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[Config] BOOST_HAS_PTHREAD_MUTEXATTR_SETTYPE not defined in MACOS for GCC-5
by Vicente J. Botet Escriba 29 Oct '15

29 Oct '15

Hi John, I'm having an issue with gcc-5.1 on MacOs. BOOST_HAS_PTHREAD_MUTEXATTR_SETTYPE is not defined. I see that there are things like #if __MACH__ && !defined(_MSL_USING_MSL_C) ... # if (__GNUC__ == 4) // Both gcc and intel require these. # define BOOST_HAS_PTHREAD_MUTEXATTR_SETTYPE # define BOOST_HAS_NANOSLEEP # endif #else ... // BOOST_HAS_PTHREAD_MUTEXATTR_SETTYPE not defined here #endif Wondering why the GCC version must be 4 and why when _MSL_USING_MSL_C is defined these PTHREAD attributes are not defined neither. BTW, when I compile with version 4 everything works correctly. Vicente

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[website] update version for Oracle Solaris Studio on the Boost website
by Aparna Kumta 29 Oct '15

29 Oct '15

The Boost1.59 page at http://www.boost.org/users/history/version_1_59_0.html under 'Compilers Tested' section, contains an entry for Sun( Oracle Solaris Studio). This needs modification for the upcoming Boost 1.60 release for which I would like to submit a PR. I looked at https://github.com/boostorg/website but not sure if this is the correct repository. Could someone please point me as to where I need to submit the PR? Thanks, Aparna

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[graph] dijkstra pull request ping
by Piotr Wygocki 28 Oct '15

28 Oct '15

Dear all, this mail concerns this pull request: https://github.com/boostorg/graph/pull/13 which is currently over one year long. Maybe, the idea of the patch is unclear or needs some additional discussion. The patch solves the problem which arises when using no_init version on dijkstra algorithm and passing a custom distance_map. This algorithm is implemented as call to BFS, which is very unfortunate since it is not BFS. Maybe BFS could be seen as special case of dijkstra with custom priority queue but not the other way around. The current implementation introduces some inefficiencies, which are described in the pull request's comment. I've created very short and direct patch which makes the implementation straight forward. Additionally, the unit test is added to check mentioned efficiency gain. Are there any additional questions concerning this pull request? Could it be possibly be merged to master? Maybe, we can use a favour of the community maintenance team. Regards, Piotr Wygocki

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Boost.Log 1.59.0 incompatible with MSVC option /Zc:wchar_t-
by Giel van Schijndel 28 Oct '15

28 Oct '15

Hi, I'm trying to build Boost.Log on MSVC9 (aka Visual Studio 2008) with the [/Zc:wchar_t-][1] option (necessary due to a vendor's SDK we're using). Unfortunately this fails to build. The mentioned option turns wchar_t into a typedef to unsigned short (i.e. it's not longer a distinct type). TLDR: My question _why_ is boost::log::aux::is_character_type<wchar_t> excluded when BOOST_NO_INTRINSIC_WCHAR_T is #defined? I see no harm in including it unconditionally. For some reason however, the template meta-function boost::log::aux::is_character_type<T>'s specialisation for wchar_t is guarded by !defined(BOOST_NO_INTRINSIC_WCHAR_T) [2]. This means wchar_t is _not_ regarded as a character type and prevents instantiation of the boost::log::aux::code_convert functions [3] which are _still_ used. The only reason I can see for excluding this is to prevent a _potential_ conflict with multiple specialisations for the same type (because of the typedef nature of wchar_t). But the only other specialisation that could potentially give a conflict is the one for char16_t, and that's mandated by C++11 to be a distinct type (AFAIK the only reason why wchar_t isn't always distinct type on Windows/MSVC is because they introduced the type pre-standardisation, so I see no reason why that mistake should be repeated for char16_t). For reference, the mentioned option's usage is detected in boost by this option preventing #definition of _NATIVE_WCHAR_T_DEFINED to indicate it did this. In boost/config/compiler/visualc.hpp there's the following code: > #ifndef _NATIVE_WCHAR_T_DEFINED > # define BOOST_NO_INTRINSIC_WCHAR_T > #endif [1]: https://msdn.microsoft.com/en-us/library/ms933181.aspx [2]: https://github.com/boostorg/log/blob/boost-1.59.0/include/boost/log/detail/… [3]: https://github.com/boostorg/log/blob/boost-1.59.0/include/boost/log/detail/… -- Met vriendelijke groet, With kind regards, Giel van Schijndel

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boost lockfree queue.hpp - alternate implementation w/o compare_exchange
by boost＠mccart.us 28 Oct '15

28 Oct '15

Is there any interest in an alternate implementation of a lockfree queue that doesn't use compare_exchange (assuming it is correct, or can be made to be correct)? I have a multi-producer / multi-consumer implementation that generally doesn't suffer nearly as much from contention. On my hardware (an older high-end 64 bit x86 workstation) I get roughly comparable throughput with existing boost lockfree queue with 1 producer and 1 consumer. With 4 producers and 4 consumers I get about 3x throughput gain on existing boost lockfree queue. However, this implementation has a weakness, it suffers in over subscription scenarios (threads in middle of push/pop that lose their time-slice); with twice as many threads as cores its performances is comparable to boost lockfree queue (using try_push/try_pop, otherwise throughput is down the toilet), and with 4x thread/core ratio the throughput is somewhat less than boost lockfree queue. This was tested on Windows 7 x64 with Inel Xeon X5355 x 2 (2 sockets w/ 4 cores a piece) @ 2.66 Ghz and 32 GB RAM @ 667 MHz. The implementation can be found here: https://github.com/benmccart/GuarunteedMpmcQueue/blob/master/queue/queue.hpp Is the implementation correct? Can anyone spot any race conditions, or conditions under which the implementation would fail to work as expected (other than queue is full/empty or over-subscription)? ~Ben

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[serialization]cannot build libboost_serialization.so.1.60.0 with Oracle Solaris Studio
by Aparna Kumta 28 Oct '15

28 Oct '15

I see the following error when compiling Boost 1.60 in develop branch with Oracle Solaris Studio development compiler with -library=stlport4. "CC" -compat=5 -library=stlport4 -temp=/tmp/bn -xO4 -mt -erroff=%none -m32 -DBOOST_ALL_NO_LIB=1 -DNDEBUG -I".." -c -o "/export/home/sstrunk-tester/boost_regression/boost_regression_develop/boost_sparc-S2_stlport4/results/boost/bin.v2/libs/serialization/build/sun-next_stlport4/release/link-static/threading-multi/basic_text_iprimitive.o" "../libs/serialization/src/basic_text_iprimitive.cpp" "../boost/archive/basic_streambuf_locale_saver.hpp", line 75: Error: sync is not a member of std::ios . "../boost/archive/impl/basic_text_iprimitive.ipp", line 112: Where: While instantiating "boost::archive::basic_ios_locale_saver<char, std::char_traits<char>>::~basic_ios_locale_saver()". "../boost/archive/impl/basic_text_iprimitive.ipp", line 112: Where: Instantiated from boost::archive::basic_text_iprimitive<std::istream>::basic_text_iprimitive(std::istream &, bool). "../libs/serialization/src/basic_text_iprimitive.cpp", line 25: Where: Instantiated from non-template code. 1 Error(s) detected. This seems to prevent building libboost_serialization.so.1.60.0, and a recent regression after changes to the serialization library. Thanks, Aparna

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[type_traits][multi_index][msvc-7.1] problems with is_const in VC 7.1
by Joaquin M López Muñoz 27 Oct '15

27 Oct '15

> Hi, Boost.MultiIndex is failing at master for VC 7.1: http://tinyurl.com/oxflkj6 .\boost\multi_index\identity.hpp(75) : error C2535: 'Type &boost::multi_index::detail::const_identity_base<Type>::operator() (const boost::reference_wrapper<Type> &) const' : member function already defined or declared the problem seemingly being with boost::is_const. The offending code looks like template<typename Type> struct const_identity_base { // produces the error above if Type is not const }; template<typename Type> struct non_const_identity_base { ... }; template<class Type> struct identity: mpl::if_c< is_const<Type>::value, detail::const_identity_base<Type>, detail::non_const_identity_base<Type> >::type { }; Boost.TypeTraits recently changed its is_const implementation to the very simple template <class T> struct is_const : public false_type {}; template <class T> struct is_const<T const> : public true_type{}; template <class T, size_t N> struct is_const<T const[N]> : public true_type{}; template <class T> struct is_const<T const[]> : public true_type{}; which relies on template partial specialization (supposedly supported by VC 7.1). Yet, seems like const_identity_base is wrongly selected for a non-const Type. Any clues about what might be going on? Thank you, Joaquín M López Muñoz Telefónica

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[tools] updating sun.jam
by Aparna Kumta 27 Oct '15

27 Oct '15

I am not familiar with the syntax to update sun.jam file. In tools/build/src/tools/sun.jam, lines 153-156 contain 153: actions link.dll bind LIBRARIES 154: { 155: "$(CONFIG_COMMAND)" $(OPTIONS) -L"$(LINKPATH)" -R"$(RPATH)" -o "$(<)" -h$(<[1]:D=) -G "$(>)" "$(LIBRARIES)" -Bdynamic -l$(FINDLIBS-SA) -Bstatic -l$(FINDLIBS-ST) -B$(LINK-RUNTIME) 156: } Only if compiling with -std=c+11 or -std=c++14, I need to replace '-G' above with '-G -library=stdcpp,CrunG3' Any help on modifying this is appreciated. Thanks, Aparna

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1.60 closes for major changes next Wednesday
by Vladimir Prus 27 Oct '15

27 Oct '15

1.60 is now closed for new libraries and breaking changes - please don't merge such changes for master. We'll be closed for major changes next Wednesday, Oct 28, at the end of the day. Thanks, -- Vladimir Prus http://vladimirprus.com

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[vmd] Added to new release
by Edward Diener 26 Oct '15

26 Oct '15

I would like to make sure the VMD library is added to the upcoming Boost 1.60 release. Is there anything further I have to do to affect that ?

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[Hana] Postponing release to 1.61.0
by Louis Dionne 24 Oct '15

24 Oct '15

Hi, Some of you might know that I have been pushing hard to deliver Hana with the next Boost release. I have even taken the (soft) engagement to do so at CppCon in last September. However, due to some time constraints, it is now clear that Hana will not be included in Boost 1.60.0, the limit for new libraries being yesterday. I hoped really hard to make it in time for Boost 1.60.0, but the closing of the release branch ~1 month before the release date got me by surprise. All in all, this is not too bad since there are still a couple issues that must be addressed, and I believe that taking more time to address them properly will be beneficial to the community in the long term. Also, while I really wanted to make Hana available to the wider community ASAP, I do not think waiting 3 more months will be very harmful. Given the current level of C++14 support in compilers, only people on Clang >= 3.5 would have been able to use Hana, and I do not think this represents such a huge amount of potential users. As a side note, given my previous announcements, some users might find it strange not to see Hana as part of 1.60.0. Hence, I wonder whether it would be possible to include a short note with a link to this message somewhere in the release notes for 1.60.0? Regards, Louis

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[detail] Compilation broken in develop and some questionable ideas
by Antony Polukhin 24 Oct '15

24 Oct '15

Hi, The commit https://github.com/boostorg/detail/commit/9fcf2ae390c7c21a9b42fd40dd5c0eec1… breaks the compilation of Boost.Filesystem: D:\t08\run\boost_root\boost/detail/utf8_codecvt_facet.hpp(126): error C2487: 'do_in': member of dll interface class may not be declared with dll interface D:\t08\run\boost_root\boost/detail/utf8_codecvt_facet.hpp(136): error C2487: 'do_out': member of dll interface class may not be declared with dll interface D:\t08\run\boost_root\boost/detail/utf8_codecvt_facet.hpp(152): error C2487: 'get_octet_count': member of dll interface class may not be declared with dll interface D:\t08\run\boost_root\boost/detail/utf8_codecvt_facet.hpp(156): error C2487: 'get_cont_octet_out_count': member of dll interface class may not be declared with dll interface D:\t08\run\boost_root\boost/detail/utf8_codecvt_facet.hpp(189): error C2487: 'do_length': member of dll interface class may not be declared with dll interface According to MSDN only the whole class or class separate members could be decorated with BOOST_UTF8_DECL, not both ( https://msdn.microsoft.com/en-us/library/t72ahzw1.aspx) Now the questionable part... We could theoreticaly avoid duplication of `utf8_codecvt_facet` code in libraries and even avoid code breakage if we: * move `struct utf8_codecvt_facet` to namespace `boost::detail::utf8_codecvt_facet_namespace` * mark all it's functions as inline, even the virtual ones => `inline` will implicitly mark the stuff in `struct utf8_codecvt_facet` as weak symbols, so that multiple occurences of it will be reduced to one by linker * add the using declaration `BOOST_UTF8_BEGIN_NAMESPACE using boost::detail::utf8_codecvt_facet_namespace::utf8_codecvt_facet; BOOST_UTF8_END_NAMESPACE` => using declaration will help the existing code to find class in `BOOST_UTF8_BEGIN_NAMESPACE` defined namespaces. Questionable part number two... Is it time to move Boost.Detail module into Boost.Core/Boost.Algorithm/Boost.MPL? Main points are: * Boost.Detail is really old and many people who maintained it are inactive. Moving it into rapidly developing modules will improve it's support (maybe even docs will appear! or tests!) * Nobody knows what does `Deatil` mean in that particular case. `detail::` namespace is a namespace that user must not use. However there's some cool stuff in Detail module that must be available to users, so the name Detail is obfuscating here. -- Best regards, Antony Polukhin

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Painting a bikeshed ...
by Marshall Clow 21 Oct '15

21 Oct '15

In Sean Parent's CppCon keynote last week, he went through the process of implementing an algorithm he called "sort_subrange", which takes four iterators describing two ranges, one a subset of the other, and sorts the subrange - as if you had sorted the entire range. (See https://www.youtube.com/watch?v=sWgDk-o-6ZE, starting at about 31:30). I have implemented this in Boost.Algorithm (crediting Sean) - called partition_sort. However, while I was doing this, I thought of a different algorithm; one that gathered all the elements into the subrange as if the entire range was sorted, but didn't actually do the sorting. I've implemented that one, too - but I'm having a bit of trouble coming up with a name. I've used "partition_subrange", but that not that clear. Sean has suggested "elements_in_subrange" and "elements_within_subrange". Here's the declaration: template<typename Iterator, typename Pred> void partition_subrange ( Iterator first, Iterator last, Iterator sub_first, Iterator sub_last, Pred p) /// \brief Gather the elements of the subrange [sub_first, sub_last) that is /// inside the range [first, last) as if you had sorted the entire range. Any suggestions? -- Marshall

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(no subject)
by Kabir Sahni 21 Oct '15

21 Oct '15

Hello! I have recently joined the mailing list and i am willing to contribute.Can anyone guide me

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[metaparse] Transferring the repository to Boostorg
by Abel Sinkovics 21 Oct '15

21 Oct '15

Hi, I'd like to transfer my Metaparse repository (https://github.com/sabel83/metaparse) to Boostorg. Based on another thread on Hana, I assume I need temporary admin rights to boostorg to be able to transfer the repository. Please give me temporary admin rights (I've posted an issue for it as well: https://github.com/boostorg/admin/issues/110) or suggest another method for the repository transfer. Thanks, Abel

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[Locale] New utf-8 codecvt facet in master (replacement of boost/details/utf8_codect_facet)
by Artyom Beilis 21 Oct '15

21 Oct '15

Hello, Following previous discussion regarding utf-8 facet in boost. I merged the changes to master branch. New utf8 codecvt facet that properly handles both UTF-16 and UTF-32 encoding for wchar_t (or char16_t/char32_t) is there. The major goal is to replace existing broken (*) utf8 facet existing today in boost/details/utf8_codecvt_facet.hpp/ipp It is implemented in header only so all you need is to include #include <boost/locale/utf8_facet.hpp> And install it as usual: std::locale new_locale(std::locale(),new boost::locale::utf8_codecvt<wchar_t>()); It *does not require* a separate compilation part like the one in details Note it is implemented in terms of boost::locale::generic_codecvt template<typename CharType,typename CodecvtImpl,int CharSize=sizeof(CharType)> class generic_codecvt; That has non-trivial specialization for CharSize=2 and CharSize=4 for UTF-16 and UTF-32 wchar_t/char16_t/char32_t character handling. boost::locale::generic_codecvt provides an interface for creating a range of facets for various character encodings. For example boost.locale uses it to implement various facets: - utf8 codecvt - single byte character set like ISO-8859-* or Windows-125* - wrap ICU ucnv_* and POSIX iconv APIs to create standard codecvt facet. That is why I decided to keep the implementation withing Boost.Locale library as the place that actually deals with different encoding. ----------- Once boost 1.60 will be released I encourage every library maintainer that incorporates broken boost/details/utf8_codecvt_facet.*pp to replace one with proper one from boost.locale Note: it is HEADER ONLY part and does not require any part of compiled library. Artyom Beilis (*) Current implementation does not handle utf-16 properly and can actually produce invalid utf-8

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[Hana] Transferring repository to boostorg on GitHub
by Louis Dionne 19 Oct '15

19 Oct '15

Hi, I would like to know what is required from me to transfer the Hana repository from my GitHub account to boostorg. I reckon I should be added as a member of the boostorg "organization" on GitHub? Regards, Louis

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Re: [boost] [interprocess] Interprocess mutex not working / throwing exception when trying to write lock
by nav999 19 Oct '15

19 Oct '15

> Hi, > > 1. Your lockWithWriteLock and lockWithReadLock create a lock, which locks > on construction and unlocks on destruction, hence when the function > returns no lock is held on the mutex. > > 2. The fact that you put a scope here makes me think that your intention > is for the lock to be unlocked at the end of this scope (which it won't, > as it is unlocked way before, as per #1). > > { > std::cout<<"Program 1: Before first locking > -------------------------- 1 v\n"; > temp.sharedMutex->lockWithWriteLock(); > const unsigned int SLEEP_TIME_IN_SECOND = 60; > std::cout<<"Program 1: sleep for "<< SLEEP_TIME_IN_SECOND << "\n"; > sleep(SLEEP_TIME_IN_SECOND); > std::cout<<"Program 1: Finished sleeping\n"; > } > > In this case though, you would perform the wait in bold while still > holding the lock, and hence preventing the 2nd program from locking it. > Once out of the scope you destroy the object right away. > > NOTE: both the issue in #1 and #2 lead to your first program possibly > deleting the mutex before the 2nd program is done with it. Which leads to > the issue you are experiencing. > > 3. If you need to have the 1st program wait for the 2nd program to be > done, then do not use sleeps, use a condition_variable. Thanks. I didn't know the lock unlocks on destruction. I had taken a cue from a post on StackOverflow: http://stackoverflow.com/questions/12439099/interprocess-reader-writer-lock… I'm using sleep only for testing purpose. The dilemma still is, how to make the mutex visible to both processes? This thread got rejected by the admin who suggested it could be posted on the users subforum, so kindly reply to my post there to continue the discussion: http://boost.2283326.n4.nabble.com/interprocess-Interprocess-mutex-not-work… -- View this message in context: http://boost.2283326.n4.nabble.com/interprocess-Interprocess-mutex-not-work… Sent from the Boost - Dev mailing list archive at Nabble.com.

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[interprocess] How to know how much memory is taken up by an object allocated in boost interprocess shared memory?
by nav999 19 Oct '15

19 Oct '15

Re-posting, as the boost mailing list rejected the first post <http://boost.2283326.n4.nabble.com/How-to-know-how-much-memory-is-taken-up-…> mentioning that I had to add "[interprocess]" to the subject line. I have asked this question on stackoverflow <http://stackoverflow.com/questions/30642585/why-does-an-object-allocated-in…> , but got no response. For this program: #include <iostream> #include <boost/interprocess/mapped_region.hpp> #include <boost/interprocess/managed_shared_memory.hpp> #include <boost/interprocess/containers/list.hpp> #include <iostream> #define SHARED_MEMORY_NAME "SO12439099-MySharedMemory" #define DATAOUTPUT "OutputFromObject" #define INITIAL_MEM 650000 #define STATE_MATRIX_SIZE 4 using namespace std; namespace bip = boost::interprocess; class SharedObject { public: unsigned int tNumber; bool pRcvdFlag; bool sRcvdFlag; unsigned long lTimeStamp; }; typedef bip::allocator<SharedObject, bip::managed_shared_memory::segment_manager> ShmemAllocator; typedef bip::list<SharedObject, ShmemAllocator> SharedMemData; int main() { bip::managed_shared_memory* seg; SharedMemData *sharedMemOutputList; bip::shared_memory_object::remove(DATAOUTPUT); seg = new bip::managed_shared_memory(bip::create_only, DATAOUTPUT, INITIAL_MEM); const ShmemAllocator alloc_inst(seg->get_segment_manager()); sharedMemOutputList = seg->construct<SharedMemData>("TrackOutput")(alloc_inst); std::size_t beforeAllocation = seg->get_free_memory(); std::cout<<"\nBefore allocation = "<< beforeAllocation <<"\n"; SharedObject temp; sharedMemOutputList->push_back(temp); std::size_t afterAllocation = seg->get_free_memory(); std::cout<<"After allocation = "<< afterAllocation <<"\n"; std::cout<<"Difference = "<< beforeAllocation - afterAllocation <<"\n"; std::cout<<"Size of SharedObject = "<< sizeof(SharedObject) <<"\n"; std::cout<<"Size of SharedObject's temp instance = "<< sizeof(temp) <<"\n"; }//main The output is: Before allocation = 649680 After allocation = 649632 Difference = 48 Size of SharedObject = 16 Size of SharedObject's temp instance = 16 If the size of SharedObject and it's instance is 16 bytes, then how can the difference in allocation be 48? Even if padding had automatically been done, it's still too much to account for 3 times the size (for larger structures it goes to 1.33 times the size). Because of this, I'm unable to allocate and dynamically grow the shared memory reliably. If SharedObject contains a list which grows dynamically, that could add to the uncertainty of space allocation even more. How can these situations be safely handled? How can I know exactly how much of memory to allocate? -- View this message in context: http://boost.2283326.n4.nabble.com/interprocess-How-to-know-how-much-memory… Sent from the Boost - Dev mailing list archive at Nabble.com.

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Do you know of standard implementation of async() that blocks on the future-destructor?
by Vicente J. Botet Escriba 18 Oct '15

18 Oct '15

Hi, all is in the title. Best, Vicente

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[Math] Help needed with FreeBSD failures
by John Maddock 18 Oct '15

18 Oct '15

Can anyone familiar with FreeBSD help me figure out what's causing a large number of runtime failures from Boost.Math, for example http://www.boost.org/development/tests/develop/developer/output/Flast-FreeB… Strangely gcc-5.1.0 is fine, but 4.8.5, 5.2.0 and 6.0 all fail. Many thanks in advance, John.

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[serialization] Massive failures in develop?
by John Maddock 18 Oct '15

18 Oct '15

Local testing seems to have badly failed: http://www.boost.org/development/tests/develop/developer/serialization.html I've only looked at the msvc failures, and there's an issue in the iostream class destructor - which is to say after the archive classes have been destructed, the iostream class they were using is left in a non-sane state. Beyond that I haven't been able to get anything sensible out of the debugger (looks like memory corruption actually, but I can't be sure). Any ideas? Thanks, John.

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[thread] Do we can a non backward compatible version with non-blocking futures?
by Vicente J. Botet Escriba 18 Oct '15

18 Oct '15

Hi, in Boost 1.58 I fixed some issues as the result of the async and future<T>:then() was not a blocking future as the documentation described. However the implementation is horrible and I suspect that it is subject to deadlocks. BTW, I added already some fixes on the develop branch. Sometime ago I started in a branch an implementation that don't use blocking futures [1]. Well the implementation is also horrible after making futures non-blocking, but less ;-) The problem is that now I have some issues with the executors :( Anyway, Gor has told me that with the blocking implementation he is unable to define await_suspend (using resumable functions) >It is just if .then returns a blocking future, I cannot subscribe a callback to .then in await_suspend. >await_suspend(f, cb) { > f.then(cb); >} &will block here preventing coroutine from suspending I don't know yet if he will reach to configure boost::future<T> on the non-blocking branch. My question is if the Boost community will accept (or even wants) a breaking change on a near release (when I would reach to fix the executors issues) including non-blocking futures instead of the current blocking futures. Best, Vicente [1] https://github.com/boostorg/thread/tree/feature/non_blocking_futures

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[intrusive]: determine the hook type of intrusive::list<>?
by Oliver Kowalke 18 Oct '15

18 Oct '15

I'd like to determine the hook type of an intrusive container (intrusive::list): template< typename List > void do_link( List & lst) { static_assert(std::is_same< typename List::???, my_hook_type >::value); lst.push_back( * this); } In the documentation I didn't found a hint. Oliver

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[regression] New runners for old compilers MSVC-7.1 and GCC 3.4
by Ion Gaztañaga 17 Oct '15

17 Oct '15

Hi, The last compiler update two years ago in Boost 1.55 left MSVC-7.1 and GCC 3.3 as two of the oldest supported compilers: http://www.boost.org/users/history/version_1_55_0.html I have no access to GCC 3.3 but managed to get a Mingw-based GCC 3.4. I will run regressions for for both mingw-GCC-3.4 and msvc-7.1 in master and develop branches in case anyone is interested. I plan to maintain support for them in Move, Intrusive, Container and Interprocess until we reach consensus on a new compiler update. Best, Ion

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[python] Merging pull request #25
by Edward Diener 17 Oct '15

17 Oct '15

The PR is necessary so that user's of Python to not see a deprecated warning coming from the updated type_traits whenever they use Boost python. Would the maintainer of Boost Python please take a look at this simple PR so we can get this in the upcoming release. Thanks !

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[Build] Specify compiler on the command line
by Louis Dionne 17 Oct '15

17 Oct '15

Hi, Still attempting to setup Boost.Build for Hana, I find myself unable to specify the compiler to be used by `b2` on the command line. The system compiler is then used by default, which does not work because I need to test on recent compilers. This can be handled by writing a project-config.jam file with the following in it: import feature ; if ! clang in [ feature.values <toolset> ] { using clang : : /path/to/clang ; } However, this is not very script-friendly, and I wonder whether there's a way to specify it on the command-line instead. Regards, Louis

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[iterator][range] Synchronization on 'master'
by Edward Diener 16 Oct '15

16 Oct '15

I have pushed a number of changes to iterator from 'develop' to 'master' for the next release. A series of these changes on 'develop', by Marcel Raad, is an attempt to remove from 'iterator' the use of the deprecated headers 'boost/iterator.hpp' and 'boost/detail/iterator.hpp' in favor of using 'std::iterator' directly instead of 'boost::iterator' and 'std::iterator_traits' and 'std::distance' directly instead of 'boost::detail::iterator_traits' and 'boost::detail::distance'. Essentially these changes mean that any other library using 'iterator' classes would fail if they attempted to refer to 'boost::iterator', 'boost::detail::iterator_traits', or 'boost::detail::distance'. After I had pushed these changes to 'master' I noticed that it broke 'range' on 'master' and reverted these specific pushed commits on iterator 'master'. On 'develop' the 'range' library ( and possibly other libraries using 'iterator' ) had been changed so that it correctly used the 'std::iterator' terminology rather than the deprecated 'boost::iterator' terminology. If we are going to make this change to 'iterator' on 'master' it needs to be co-ordinated with the same set of changes for other libraries which now work with these changes on 'develop'. I noticed quite a few changes for 'range' on 'develop' which have not been pushed to 'master' for the upcoming release. I will assume that the maintainer of 'range' will want to push these changes to 'master' for the upcoming release so this is a heads up that the changes ( actually the last 'develop' commit for 'range' ) need to be co-ordinated with 'iterator' if it is done. Similarly if any other library depending on 'iterator' needs these changes on 'master' it needs to be co-ordinated with 'iterator'. I will NOT be re-pushing these changes on 'iterator' until this co-ordination is in place as I do not want to break 'master' in the interim. I am also fine with waiting until after this upcoming release to re-push these 'iterator' change to 'master' if that is what is desired by others, but any library currently depending on these changes in 'develop' must be aware of what the decision end up to be.

5 9

[serialization] Test runners being stopped
by Tom Kent 16 Oct '15

16 Oct '15

I think there is a bug in the serialization library that is breaking out of the test harness and causing window's error handling to kick in (when running on Windows, obviously). Usually when this happens the test runner application eventually (I believe) times out the test and marks it as failed. However, there are an incredible number of failures happening (since late last week) and they are bogging down the entire test run. Most of the runs I have attempted in the last week on windows have failed...the ones that have succeeded have taken ~12hrs up from the normal 3-4hrs. I was able to capture a stack trace of one of these random failures: msvcp140d.dll!00007ff9cfffb968() Unknown msvcp140d.dll!00007ff9cff73005() Unknown > test_list_ptrs_text_warchive.exe!std::basic_filebuf<wchar_t,std::char_traits<wchar_t> >::_Endwrite() Line 649 C++ test_list_ptrs_text_warchive.exe!std::basic_filebuf<wchar_t,std::char_traits<wchar_t> >::close() Line 341 C++ test_list_ptrs_text_warchive.exe!std::basic_filebuf<wchar_t,std::char_traits<wchar_t> >::~basic_filebuf<wchar_t,std::char_traits<wchar_t> >() Line 155 C++ test_list_ptrs_text_warchive.exe!std::basic_ofstream<wchar_t,std::char_traits<wchar_t> >::~basic_ofstream<wchar_t,std::char_traits<wchar_t> >() Line 1068 C++ test_list_ptrs_text_warchive.exe!std::basic_ofstream<wchar_t,std::char_traits<wchar_t> >::`vbase destructor'() C++ test_list_ptrs_text_warchive.exe!test_list() Line 65 C++ test_list_ptrs_text_warchive.exe!test_main(int __formal, char * * __formal) Line 176 C++ test_list_ptrs_text_warchive.exe!main(int argc, char * * argv) Line 203 C++ [External Code] I'd be happy to help get to the bottom of this, if you can give me any more diagnostic steps to take. We need to resolve this ASAP because it is preventing the windows test runners from producing timely results and we have a release coming up. Thanks, Tom

2 3

[test] BOOST_PP_VARIADICS is defined twice
by Andrey Semashev 16 Oct '15

16 Oct '15

Hi, For some reason Boost.Test defines the BOOST_PP_VARIADICS macro, which, I believe, is a macro defined by Boost.Preprocessor. This results in build errors as can be seen here: http://www.boost.org/development/tests/develop/developer/output/teeks99-01b… I think Boost.Test should not define BOOST_PP_VARIADICS and rely on Boost.PP for that. In any case, BOOST_PP* is not the namespace of Boost.Test.

2 4

[fusion] result_of_with_decltype is missing
by Andrey Semashev 16 Oct '15

16 Oct '15

Hi, I can see many of my tests are failing like this: http://www.boost.org/development/tests/develop/developer/output/teeks99-01b… Basically, it complains that fusion::detail::result_of_with_decltype is missing and indeed I cannot find it defined in Boost.Fusion anywhere.

1 0

Valgrind reports use of uninitialized value in any_range
by Auer, Jens 16 Oct '15

16 Oct '15

Hi, I am using an any_range of std::unique_ptr values in one of my programs. When I analyse this with valgrind, it reports many uninitialized value usages in any_range, and I cannot explain this from my code. I managed to produce a small example to reproduce this. I would like to know if that is a real issue, or if can just create a valgrind suppression rule. #include <iostream> #include <boost/range.hpp> #include <boost/range/any_range.hpp> #include <boost/range/adaptors.hpp> struct Int { Int(int i): x(i) {} int x; }; int main( int argc, char* argv[] ) { typedef boost::any_range<Int*, boost::forward_traversal_tag, Int*, std::ptrdiff_t> R; std::vector<std::unique_ptr<Int>> v; v.push_back( std::make_unique<Int>(42) ); auto f = [](std::unique_ptr<Int> const& p) {return p.get();}; R r = v | boost::adaptors::transformed(f); auto x = (*boost::begin(r))->x; std::cout << x << std::endl; return 0; } Running this, valgrind reports a "Use of uninitialized value of size 8": # g++ --version g++ (GCC) 5.2.0 # g++ -std=c++1y -o test test.cpp # valgrind --version valgrind-3.11.0 # valgrind --track-origins=yes ./test ==8119== Memcheck, a memory error detector ==8119== Copyright (C) 2002-2015, and GNU GPL'd, by Julian Seward et al. ==8119== Using Valgrind-3.11.0 and LibVEX; rerun with -h for copyright info ==8119== Command: ./test ==8119== ==8119== Use of uninitialised value of size 8 ==8119== at 0x4010B8: main (in /tmp/test) ==8119== Uninitialised value was created by a stack allocation ==8119== at 0x40315D: boost::range_detail::any_iterator<Int*, boost::iterators::forward_traversal_tag, Int*, long, boost::any_iterator_buffer<64ul> >::dereference() const (in /tmp/test) ==8119== 42 ==8119== ==8119== HEAP SUMMARY: ==8119== in use at exit: 72,704 bytes in 1 blocks ==8119== total heap usage: 3 allocs, 2 frees, 72,716 bytes allocated ==8119== ==8119== LEAK SUMMARY: ==8119== definitely lost: 0 bytes in 0 blocks ==8119== indirectly lost: 0 bytes in 0 blocks ==8119== possibly lost: 0 bytes in 0 blocks ==8119== still reachable: 72,704 bytes in 1 blocks ==8119== suppressed: 0 bytes in 0 blocks ==8119== Rerun with --leak-check=full to see details of leaked memory ==8119== ==8119== For counts of detected and suppressed errors, rerun with: -v ==8119== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 1 from 1) Best wishes, Jens PS: I've sent this to boost-users yesterday, but I now think that boost-devel is a better match. -- Dr. Jens Auer | CGI | Software Engineer CGI Deutschland Ltd. & Co. KG Rheinstraße 95 | 64295 Darmstadt | Germany T: +49 6151 36860 154 jens.auer(a)cgi.com Unsere Pflichtangaben gemäß § 35a GmbHG / §§ 161, 125a HGB finden Sie unter de.cgi.com/pflichtangaben. CONFIDENTIALITY NOTICE: Proprietary/Confidential information belonging to CGI Group Inc. and its affiliates may be contained in this message. If you are not a recipient indicated or intended in this message (or responsible for delivery of this message to such person), or you think for any reason that this message may have been addressed to you in error, you may not use or copy or deliver this message to anyone else. In such case, you should destroy this message and are asked to notify the sender by reply e-mail.

2 1

Beginner Request for Contributing to Boost Library
by Arafat Khan 16 Oct '15

16 Oct '15

Hi Respected Sir/ Mam, I am Arafat Dad Khan, an undergraduate student at Indian Institute of Technology, Kharagpur. I wish to contribute to the Boost Library (Specifically Graph and Data Structures). I have decent knowledge of Algorithms and Data Structures and have consistently taken part in algorithmic competitions on websites such as Codechef and Spoj(Sphere online Judge ) you can view my profile here http://www.spoj.com/SPOJ/users/adk/ I am very new to open source, And i just need someone to guide me so that i could focus on the right areas to contribute. I am very comfortable with C++ language and learning complicated algorithms is great fun to me. Can anyone please tell me the ways in which i could contribute? If this is not the right place to ask newbie questions please tell me where i could ask the my questions. Thanks Arafat Dad Khan Indian Institute of Technology Kharagpur

4 3

We need a coherent higher level parallelization story for C++ (was [thread] Is there a non-blocking future-destructor?)
by Hartmut Kaiser 16 Oct '15

16 Oct '15

Sorry for cross-posting. > Vicente J. Botet Escriba wrote: > > I have a branch > (https://github.com/boostorg/thread/tree/feature/non_blocking_futures) > that don't blocks on any future, but this will break async. FWIW, the design decision to let those (and only those) futures block on destruction which are returned from async was one of the really bad decisions made for C++11, however that's just my opinion (others agree, but yet others disagree). This flaw essentially caused us to spend many committee hours on discussions how to mitigate the situation, with proposed solutions ranging from 'leave it be as is' to as extreme as 'deprecate it now'. There seems to be a growing consensus however to develop other constructs which eventually could replace async, such as executors, etc. I'm a proponent of following that path. More generally, I strongly believe that we have to come up with a _coherent story_ for all kinds of (higher-level) parallelism in C++: task-based parallelism, asynchronous, continuation style programming, fork-join parallelism of heterogeneous tasks, simple fork-join (iteration based) parallelism, etc. All of this has to go hand in hand with a (orthogonal) vectorization story. We also need to think about integrating GPUs. The goal has to be to make parallelism in C++ independent of any external solutions such as OpenMP, OpenACC, etc. Many of the building blocks for this are already being discussed: executors and executor_traits for customizing the 'how and where' of task execution, executor parameters for grain-size control, and execution policies as the higher level facility allowing to tie everything together (see for instance HPX [7]). We (as a committee) already allow for passing execution policies as the first argument to parallel algorithms (Parallelism TS, N4505 [2]). We already have some facilities for task-based, asynchronous, and continuation style parallelism in place (Concurrency TS, N4501 [3]). We have a paper proposing task_blocks for fork-join parallelism of heterogeneous tasks (N4411 [4]). We have two competing (but converging) efforts for defining an executor concept (N4406 [5], PR0008R0 [6]). We have a (strong) proposal for simplifying continuation based programming (await, PR0057R0 [8]). We have attempts on integrating executors with existing facilities (Boost, HPX). We miss work on parallel ranges. We miss work on integrating data structures with data placement policies in conjunction with executors. We miss work on extending all of this to many-core, distributed, and high-performance computing. Etc. We (as a community) really need a higher level, over-arching approach which ties all of the above together! My plan is to work on a corresponding concept paper by the time of the committee meeting end of February 2016. Our group has outlined our current understanding and a possible approach to this here [1]. I'd like for this to be understood as a seed for a wider discussion. Needless to say, I'd very much like to collaborate on this with anybody interested in joining the effort. Regards Hartmut --------------- http://boost-spirit.com http://stellar.cct.lsu.edu [1] http://stellar.cct.lsu.edu/pubs/executors_espm2_2015.pdf [2] http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4505.pdf [3] http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4501.html [4] http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4411.pdf [5] http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4406.pdf [6] http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0008r0.pdf [7] http://stellar-group.github.io/hpx/docs/html/hpx/manual/parallel.html [8] http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0057r0.pdf

5 10

[WG21 mailing] N4453 Resumable expressions
by Niall Douglas 15 Oct '15

15 Oct '15

I'm finding Chris' paper on resumable expressions instead of compiler magic created resumable functions awfully compelling: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4453.pdf I essentially proposed the same with my functionally composed constexpr basic_future design some months ago. Would anyone else like to comment on this library based instead of compiler based resumable execution? I'm not against some compiler support for resumable execution, but I am finding the await based proposal highly problematic, and Chris does an excellent job in summarising my own thoughts on what's wrong with it. Niall -- ned Productions Limited Consulting http://www.nedproductions.biz/ http://ie.linkedin.com/in/nialldouglas/

10 17

Policy for individual library versioning
by Louis Dionne 15 Oct '15

15 Oct '15

Hi, I wonder whether there is a policy for how to version individual Boost libraries. Should individual libraries follow their own versioning scheme, or should they stick to the Boost versioning scheme? For example, Hana is currently in v0.4 and following Semantic Versioning[1]. I am wondering whether I should change Hana's version to 1.60.0 when it will be released with Boost 1.60.0, and from then on follow that versioning scheme (and drop Semantic Versioning, which I'm OK with). Hence, I would bump to 1.61.0 when Boost 1.61.0 is released, and so on. The other option is to stick with my current versioning scheme and simply document the correspondence between Hana vA.B.C and Boost vX.Y.Z. Is there any agreed-upon way to handle this? Regards, Louis [1]: http://semver.org

3 4

1.60 closes for new libraries and breaking changes in a week
by Vladimir Prus 15 Oct '15

15 Oct '15

Folks, the deadline for new libraries and breaking changes for 1.60 is next Wednesday, Oct 21. Please get big changes in by that date. Thanks, Volodya

4 7

Re: [boost] [c++std-parallel-2020] Re: We need a coherent higher level parallelization story for C++ (was [thread] Is there a non-blocking future-destructor?)
by Peter Dimov 14 Oct '15

14 Oct '15

Lawrence Crowl wrote: > First, std::async and std::future have no flaws for what they were > designed to do. They were designed to provide relatively easy parallelism > for small core systems under the fork-join model. I thought that it was well established by now that std::async isn't very useful for fork-join (if at all.) First, it's required to execute each (asynchronous) task as-if in a new thread with respect to thread locals, which in practice means "in a new thread". Second, it has to allocate the future shared state. These two non-flaws kill its performance for fork-join parallelism. The first one is not related to its use of std::future, but the second one is. Given an interface of the form X x; async_result<R> r; std::async( r, [&]{ return x.f(); } ); with async_result being non-copyable and non-movable and ~async_result blocking on the async task, the task can store its result directly into r, without needing to allocate.

1 0

Re: [boost] [c++std-parallel-2020] Re: We need a coherent higher level parallelization story for C++ (was [thread] Is there a non-blocking future-destructor?)
by Peter Dimov 14 Oct '15

14 Oct '15

Lawrence Crowl wrote: > Third, extending the use of std::future beyond its design goals caused > problems. You would expect this of any system used beyond its goals. In > particular, using std::futures for anything other than std::async was a > step too far. This is absolutely backwards. Future was always intended to be used as a generic future value. Hence the name, and the existence of 'promise'. Extending it beyond these design goals in order to imbue it with a lifetime management function caused the problems.

1 0

Test Runner Crashing
by Tom Kent 12 Oct '15

12 Oct '15

Over the weekend I've seen my windows test runner completely crashed (and other OS applications crashed as well), it is preventing the runner from getting through a complete run. I don't really have any idea where it is happening, but I have seen some errors in wserialization throwing up application crashed window...could this be related? Here's the info from the window: Problem signature: Problem Event Name: APPCRASH Application Name: test_non_intrusive_text_warchive.exe Application Version: 0.0.0.0 Application Timestamp: 561b13c0 Fault Module Name: MSVCP120D.dll Fault Module Version: 12.0.21005.1 Fault Module Timestamp: 524f8411 Exception Code: c0000005 Exception Offset: 000000000007c170 OS Version: 6.3.9600.2.0.0.272.7 Locale ID: 1033 Additional Information 1: 4de6 Additional Information 2: 4de60485dd55f55c5bf1ba0ca18762f0 Additional Information 3: 57a7 Additional Information 4: 57a7ea5113dd7a4cdeb1d88e51b65649 Read our privacy statement online: http://go.microsoft.com/fwlink/?linkid=280262 If the online privacy statement is not available, please read our privacy statement offline: C:\Windows\system32\en-US\erofflps.txt Here's the Visual Studio call stack: msvcp120d.dll!00007fff81a4c170() [Frames below may be incorrect and/or missing, no symbols loaded for msvcp120d.dll] msvcp120d.dll!00007fff819d88d2() msvcp120d.dll!00007fff819d9918() msvcp120d.dll!00007fff819e1511() > test_non_intrusive_text_warchive.exe!std::basic_filebuf<wchar_t,std::char_traits<wchar_t> >::_Endwrite() Line 643 + 0xcf bytes C++ test_non_intrusive_text_warchive.exe!std::basic_filebuf<wchar_t,std::char_traits<wchar_t> >::close() Line 341 + 0xa bytes C++ test_non_intrusive_text_warchive.exe!std::basic_filebuf<wchar_t,std::char_traits<wchar_t> >::~basic_filebuf<wchar_t,std::char_traits<wchar_t> >() Line 156 C++ test_non_intrusive_text_warchive.exe!std::basic_ofstream<wchar_t,std::char_traits<wchar_t> >::~basic_ofstream<wchar_t,std::char_traits<wchar_t> >() Line 1061 + 0x13 bytes C++ test_non_intrusive_text_warchive.exe!std::basic_ofstream<wchar_t,std::char_traits<wchar_t> >::`vbase destructor'() + 0x1c bytes C++ test_non_intrusive_text_warchive.exe!save(const char * testfile) Line 143 + 0x1b bytes C++ test_non_intrusive_text_warchive.exe!test_main(int __formal, int __formal) Line 169 C++ test_non_intrusive_text_warchive.exe!main(int argc, char * * argv) Line 203 + 0xe bytes C++ test_non_intrusive_text_warchive.exe!__tmainCRTStartup() Line 626 + 0x19 bytes C test_non_intrusive_text_warchive.exe!mainCRTStartup() Line 466 C kernel32.dll!00007fff8f7013d2() ntdll.dll!00007fff91fc5454() Any ideas? Could it be possible that too many application crashes could be taking out the test runner (and other OS applications) completely? Thanks, Tom

1 0

[Hana] Integration with the regression Matrix
by Louis Dionne 12 Oct '15

12 Oct '15

Hi, With the goal of shipping Hana with the next release of Boost, I am currently trying to satisfy the requirement that Hana's testing results show up in the Boost regression matrix. One way to achieve this would be to have Travis CI upload the results on each push to master. To do so, I would need to somehow create an XML file compatible with what the regression matrix expects. That brings up a few questions: (1) Is there a way to upload the result of CMake tests to the Boost regression matrix? I suspect something like that might have already been done as part of the (unfortunately defunct) CMake effort? (2) If not, would it be difficult to implement? Any input on how to best integrate Hana's testing results with the rest of Boost's regression testing will be greatly appreciated. Also, before someone suggests using Boost.Build: I have been looking at the possibility of maintaining a separate Jamfile. However, the need to maintain two separate build systems is annoying, so I'd like to avoid it if possible. I also think that Travis-based testing could provide a better coverage for Hana than the voluntary testers given the need for cutting edge compilers, but I could be wrong. Regards, Louis -- View this message in context: http://boost.2283326.n4.nabble.com/Hana-Integration-with-the-regression-Mat… Sent from the Boost - Dev mailing list archive at Nabble.com.

7 9

[thread] Is there a non-blocking future-destructor?
by Mikael Olenfalk 11 Oct '15

11 Oct '15

Hi, I have stumbled on a minor inconvenience when it comes to using boost::future. Below is a small example which first wraps an asio io_service as an Executor (see even further below) and then uses boost::async() to launch a simple task on the executor and tries to queue up a continuation using future::then(Ex, F): 1. the destructor of async_result does not block which is nice 2. the destructor of continuation_result does block which is a bit of an annoyance as this future I do not care about at all Is there a way to make the destructor not block? /M int main(int argc, char* argv[]) { boost::asio::io_service io_service; asio_executor executor{ io_service }; auto async_result = boost::async(executor, []() { return 42; }); // hangs: // async_result.then(executor, &g); // does not hang: auto continuation_result = async_result.then(executor, [](boost::future<int> r) { cout << r.get() << endl; }); cout << "start io_service" << endl; io_service.run(); cout << "stop io_service" << endl; return 0; } class asio_executor : public boost::executors::executor { public: asio_executor(boost::asio::io_service &ios) : _ios(ios) {} void close() override { _ios.stop(); } bool closed() override { return _ios.stopped(); } void submit(work&& w) override { // for some reason _ios.post(w); causes endless // recursion and eventually a crash _ios.post(std::move(w)); } bool try_executing_one() override { return _ios.run_one() > 0; } private: boost::asio::io_service &_ios; };

2 2

Boost.Fiber mini-review report
by Nat Goodspeed 10 Oct '15

10 Oct '15

The mini-review of Boost.Fiber by Oliver Kowalke ran from Friday September 4th through Sunday September 13th. There was lively discussion, but only two actual reviews: Agustín K-ballo Bergé: not yet (list of issues below) Niall Douglas: yes, plus suggestions (below)[0] In addition I received two "review withheld" notes: Vicente J. Botet Escriba wanted me to address the previous review point by point. That seems like a reasonable request, and I apologize, but I too have time pressures. Giovanni Piero Deretta made suggestions (synopsized below) with the statement that he will make a recommendation when he sees the library author's progress along those lines. While in theory these results might seem like a hung jury, the very paucity of formal reviews supports a cautious approach. The verdict is: not yet, with specific points as noted below. No reviewer explicitly designated specific points as being essential. (Niall Douglas explicitly designated his suggestions as post-adoption enhancements.) I have made an attempt to rank the recommendations received in descending order of importance to the community. My criteria are: Robustness: does lack of this request pose significant risk to a consuming program? API stability: could this request be considered an implementation detail, or would the change break early adopters? Demand: how many people requested the same thing? If you feel that I have misrepresented the importance of one of your points (or omitted something entirely), please respond. Ultimately, of course, the importance of any given point to the community at large will be reflected in the next mini-review. ----------------------------------------------------------------- Requests: Cross-thread fiber migration: Evidently the community strongly desires the ability to transfer a suspended fiber from one thread to another.[1] Of course there must be controls. Migration might be explicit; but if implicit, there must be a way to designate which fibers may and may not be migrated. An RAII class that temporarily disables migration would also be desirable -- for instance, to guarantee TLS consistency for some specific period. Cross-thread migration support implies a requirement to document the thread safety requirements of the customization API. Standard required timing specifications: meet (30.2.4 Timing specifications [thread.req.timing]). Adapt one or more existing test suites for thread facilities to validate the correctness of the Fiber library's synchronization constructs: e.g. from libc++, libstdc++, Boost.Thread, HPX. std::chrono support: ensure that wait_until() can accept any supported time_point specialization. (The library author asserts that this has already been fixed on the 'develop' branch.) C++11 compatibility: Agustín K-ballo Bergé volunteered to help with this point post-adoption. Paul Fultz offered fit::capture to emulate C++14 move capture. Document that this_fiber::yield() (et al.) are valid from main(), or in general from a thread function, as well as from explicitly-launched fibers. Make shared_state lock requirements explicit: for example, make mark_ready_and_notify_() accept a std::unique_lock<>& (or &&) to force its caller to provide one. Avoid holding mutex during condition_variable::notify_*() calls. (The library author asserts that this has already been fixed on the 'develop' branch.) packaged_task must not decay-copy its task arguments. Align fibers::async() signature, result description and invoke_helper implementation with std::async(). Avoid returning std::move(...). Wait list implementation: try an intrusive linked list of fiber_context objects. Avoid sleeping thread when no fibers are ready -- block on external event. Better handling of waiting tasks (decentralized wait queues?). Optimization to resume awakened fiber on the thread that awakens it. Template redundancy: eliminate duplication between specializations for T, T& and void. The future, shared_future, shared_state, promise and task_object templates were specifically cited. Leverage predicate-based condition::wait() overload internally. Nested schedulers: make schedulers be schedulable entities themselves. Improve robustness of `promise' handling in Asynchronous Callbacks documentation. Avoid overconfident remarks about it. Fix Note overstating the requirements on condition_variable::wait(). The discussion also surfaced the desirability of Grand Unified Future Theory, but it was generally agreed that this is out of scope. Put differently, it would be unreasonable to put the onus on Fiber to solve that very broad cross-library problem. Many thanks to all participants, and thanks especially to Oliver Kowalke for all his work on this library! Nat Goodspeed Boost.Fiber Review Manager ________________________________ [0] Niall Douglas snuck his review recommendation into the following mail message: http://lists.boost.org/Archives/boost/2015/09/225228.php (second to final paragraph). His suggestions were in private mail. [1] Giovanni Deretta suggests that it might be possible to allocate -- without actually running -- an actual kernel thread per fiber, simply to give each fiber its own TLS area.

2 1

Boost Library Testing - a modest proposal - was boost.test regression or behavior change (was Re: Boost.lockfree)
by Robert Ramey 10 Oct '15

10 Oct '15

I believe this whole thread started from the changes in Boost.Test such that it can no longer support testing of C++03 compatible libraries. This is totally unrelated to the testing of Boost libraries. Here is what I would like to see: a) local testing by library developers. Of course library developers need this in order to develop and maintain libraries. Currently we have this and has worked quite well for many years. Making Boost.Test require C++11+ throws a monkey wrench into things for the libraries which use it. But that's only temporary. Libraries whose developers feel they need to maintain compatibility with C++98 can move to lightweight test with relatively little effort. Developers who are concerned that the develop branch is a "soup" can easily isolate themselves from this by testing against the master branch of all the other libraries. The Boost modularization system with git has made this very simple and practicle (thank you Beman!). So - not a problem. b) Testing on other platforms. We have a system which has worked pretty well for many years. Still it has some features that I'm not crazy about. i) it doesn't scale well - as boost gets bigger the testing load gets bigger. ii) it tests the develop branch of each library against the develop branch of all the other libraries - hence we have a testing "soup" where a test might show failure but this failure might not be related to the library under test but some other library. It diminishes the utility of the test results in tracking down problems. iii) it relies on volunteer testers to select compilers/platforms to test under. So it's not exhaustive and the selection might not reflect that which people are actually using. I would like to see us encourage our users to test the libaries that they use. This system would work in the following way. a) A user downloads/builds boost. b) he decides he's going to use library X, and Y c) he runs a tool which tells him which libraries he has to test. This would be the result of a dependency analysis. We have tools which do similar dependency analysis but they would have to be slightly enhanced to distinguish between testing, deployment, etc. I don't think this would be a huge undertaking given the work that has already been done. d) he runs the local testing setup on those libraries and their dependents. e) he uploads the test results to a dashboard similar if not identical to the current one. f) we would discourage uses from just using the boost libraries without runnig they're own tests. We would do this by exhortation and by refusing to support users who have been unwilling to run and post local tests. This would give us the following: a) a scalable testing setup which could handle a Boost containing any number of libraries. b) All combinations of libraries/platforms/compilers actually being used would be those being tested and vice versa. We would have complete and efficient test coverage. c) We would have statistics on libraries being used. Something we are sorely lacking now. d) We would be encouraging better software development practices. Sometime ago someone posted that he had a problem but couldn't run the tests because "management" wouldn't allocate the time - and this was a critical human life safety app. He escaped before I could weedle out of him which company he worked. And best of all - We're almost there !!!! we'd only need to: a) enhance slightly the dependency tools we've crafted but aren't actually using. b) develop a tool to post the local results to a common dashboard c) enhance the current dashboard to accept these results. Robert Ramey

3 3

[nowide] Library Updates and Boost's broken UTF-8 codecvt facet
by Artyom Beilis 09 Oct '15

09 Oct '15

Some updated regarding boost.nowide 1. Library moved to github and its format is converted to modular boost layout: https://github.com/artyom-beilis/nowide2. Fixed unsupported std::ios::ate flag by boost::nowide::fstream3. Added some C++11 interfaces to boost::nowide::fstream4. Added integration functionality with boost::filesystem: https://github.com/artyom-beilis/nowide/blob/master/include/boost/nowide/in… And another important update is that I implemented proper utf8 to utf-16/utf-32 codecvt facet https://github.com/artyom-beilis/nowide/blob/master/include/boost/nowide/ut… It implemented as template version working with wchar_t, char16_t and char32_t. Now I explain. There is widely used utf8 codecvt facet in various parts of code: https://github.com/boostorg/detail/blob/master/include/boost/detail/utf8_co… https://github.com/boostorg/detail/blob/master/include/boost/detail/utf8_co… However it is buggy and actually broken for 3 reasons: 1. It supports UCS-2 instead of UTF-16 - i.e it does not code properly Unicode characters outside BMP i.e. code points with values abouve 0xFFFF2. It allows invalid code points in UTF-32/UCS-4 i.e. above 10FFFF or that are reserved for surrogate pairs of UTF-163. And actually allows UTF-8 sequences longer than 4 (which is wrong) As a result, for example you can't use boost::filesystem::path with characters like "𝒞" U+1D49E or may actually create wrong encodings trying to read/write filesystem objects. Independently of Boost.Nowide I would like to propose replacement of boost/detail/utf8_codecvt_facet by one thatactually takes in account proper Unicode handling. Artyom Beilis--------------CppCMS - C++ Web Framework: http://cppcms.com/CppDB - C++ SQL Connectivity: http://cppcms.com/sql/cppdb/

7 47

[Build] Test file name conflicts
by Louis Dionne 09 Oct '15

09 Oct '15

Hi, While trying to create Jamfiles for Boost.Hana's unit tests, the following situation came up. I have two unit tests in files foo/main.cpp bar/main.cpp Then, my Jamfile.v2 contains the following: import testing ; test-suite xxx : [ run foo/main.cpp ] [ run bar/main.cpp ] ; When I run `b2`, I get the following: error: No best alternative for ./main next alternative: required properties: (empty) matched next alternative: required properties: (empty) matched error: No best alternative for ./main next alternative: required properties: (empty) matched next alternative: required properties: (empty) matched I think the problem is that Boost.Build tries to create two executables named `main` in the same directory, which obviously causes a name conflict. Is there any way to avoid this, besides renaming the test files? Regards, Louis -- View this message in context: http://boost.2283326.n4.nabble.com/Build-Test-file-name-conflicts-tp4680806… Sent from the Boost - Dev mailing list archive at Nabble.com.

2 2

Boost.lockfree
by Aparna Kumta 09 Oct '15

09 Oct '15

All tests for lockfree in both master and develop branch seem to fail. Error message is "../boost/system/config.hpp", line 34: Error: #error Must not define both BOOST_SYSTEM_DYN_LINK and BOOST_SYSTEM_STATIC_LINK. See develop branch: http://www.boost.org/development/tests/develop/developer/lockfree.html See master branch: http://www.boost.org/development/tests/master/developer/lockfree.html I looked at lockfree/test/Jamfile.v2 but am not sure what change needs to be made. Any suggestions? Thanks, Aparna

17 51

[Test] breaking changes in test invocation
by Jürgen Hunold 09 Oct '15

09 Oct '15

Hi, it seems that commit c0d2d29284389a1e7f924583ff6bd59128b9436b Author: Gennadiy Rozental <rogeeff(a)gmail.com> Date: Thu Oct 1 03:38:44 2015 -0400 -- is required before extra test module arguments has at least broken my Boost.Build driven tests, as I now get: Usage: my_test-clang38 [Boost.Test argument]... -- [custom test module argument]... For detailed help on Boost.Test parameters use: my_test-clang38 --help or my_test-clang38 --help=<parameter name> for every test which has extra command line arguments. I strongly suspect this breaks some libraries in Boost itself which e.g. need to read some input files. Right now I'm lost at how to fix this in Boost.Build's testing.jam as it seems we somehow have to specify different arg sets. And how to get "--" into the commandline at all. And in the light of the ongoing c++11/03 discussion it would have been nice to issue a warning before commiting breaking and/or behavioural changes. Any ideas? Yours, Jürgen -- * Dipl.-Math. Jürgen Hunold ! * voice: ++49 4257 300 ! Fährstraße 1 * fax : ++49 4257 300 ! 31609 Balge/Sebbenhausen * jhunold(a)gmx.eu ! Germany

3 6

[Date_time] Adding Input Format Flag Parsers
by Yucheng Low 08 Oct '15

08 Oct '15

Hi, Boost date_time is missing a bunch of format flag parsers on input (%I,%l, %P, %p). Here is a proposed patch to add these format flags. Thanks, Yucheng

1 0

[regression] new runner missing in master results
by Ion Gaztañaga 08 Oct '15

08 Oct '15

Hi, Since MSVC-7.1 is (in theory) supported by Boost and we had no regressions on that platform, I've set up an old computer to do the job. I've executed regression tests several times and results appear in develop branch's result page but they are always missing in master branch. Logs indicate that executions and uploading were correct. Eg.: Runner "igaztanaga" present in develop: http://www.boost.org/development/tests/develop/developer/move.html Runner "igaztanaga" missing in develop: http://www.boost.org/development/tests/master/developer/move.html Any hint on what could be the problem? Ion

3 6

Boost.test failures in develop
by Aparna Kumta 08 Oct '15

08 Oct '15

Compiling with Oracle Solaris Studio on sparc-S2 platform with -library=stlport4, I see the following failure in the develop branch: "CC" -library=stlport4 -xO4 -mt -erroff=%none -m32 -KPIC -DBOOST_ALL_NO_LIB=1 -DBOOST_CHRONO_DYN_LINK=1 -DBOOST_SYSTEM_DYN_LINK=1 -DBOOST_SYSTEM_NO_DEPRECATED -DBOOST_TEST_DYN_LINK=1 -DBOOST_TIMER_DYN_LINK=1 -DNDEBUG -D__typeof__=__typeof__ -I".." -c -o "/export/home/b_dev/results/boost/bin.v2/libs/test/build/sun/release/stdlib-sun-stlport/threading-multi/unit_test_parameters.o" "../libs/test/src/unit_test_parameters.cpp" "../boost/test/utils/runtime/errors.hpp", line 75: Error: Templates can only declare classes or functions. "../boost/test/utils/runtime/errors.hpp", line 86: Error: Templates can only declare classes or functions. "../boost/test/utils/runtime/errors.hpp", line 124: Error: ")" expected instead of "&&". "../boost/test/utils/runtime/errors.hpp", line 133: Error: ")" expected instead of "&&". "../boost/test/utils/named_params.hpp", line 69: Error: Unexpected type name "Rest" encountered. "../boost/test/utils/named_params.hpp", line 69: Error: Unexpected ":" found. "../boost/test/utils/named_params.hpp", line 205: Error: Unexpected type name "Rest" encountered. "../boost/test/utils/named_params.hpp", line 205: Error: operator, is not defined. "../boost/test/utils/named_params.hpp", line 205: Error: "," expected instead of ";". ... Compilation aborted, too many Error messages. It seems that the code contains rvalue reference and hence the compiler is not able to build it in C++03 mode. This seems to be a recent change preventing building of libboost_unit_test_framework.a and hence causing several tests to fail. Thanks, Aparna

12 33

git reset and force push
by Raffi Enficiaud 08 Oct '15

08 Oct '15

Hi all, Is there any policy wrt. reseting a branch master/develop and force pushing? The side question is to know if the boost git tools (the bot for submodules) can cope with those operations. Thanks, Raffi

9 38

[serialization] static_warning.hpp seems behind boost/config
by Alain Miniussi 07 Oct '15

07 Oct '15

Hi, It seems that BOOST_STATIC_ASSERT_UNUSED_ATTRIBUTE has been replaced by BOOST_ATTRIBUTE_UNUSED in boost config. But static_warning.hpp is still using the old macro on master (while it is fixed on develop). On master: #define BOOST_SERIALIZATION_BSW(B, L) \ typedef boost::serialization::BOOST_SERIALIZATION_SS< \ sizeof( boost::serialization::static_warning_test< B, L > ) \ > BOOST_JOIN(STATIC_WARNING_LINE, L) BOOST_STATIC_ASSERT_UNUSED_ATTRIBUTE; On develop: #define BOOST_SERIALIZATION_BSW(B, L) \ typedef boost::serialization::BOOST_SERIALIZATION_SS< \ sizeof( boost::serialization::static_warning_test< B, L > ) \ > BOOST_JOIN(STATIC_WARNING_LINE, L) BOOST_ATTRIBUTE_UNUSED; Could someone move the fix from develop to master to keep in synch with boost/config ? It is preventing some tests to pass in mpi. Thanks -- --- Alain

2 2

Boost.Filesystem for Universal Windows (windows-api=store)
by Mikael Olenfalk 06 Oct '15

06 Oct '15

Hi, I made a first attempt at getting Boost.Filesystem to run on the Universal Windows Platform (Windows 10). I intend to do more testing of it before it is ready to be merged but I would very much appreciate a quick and dirty review already. If somebody could take a look I would be a very happy guy. https://github.com/boostorg/filesystem/pull/18 I am working on some more libraries in the hopes that I can finish off most libs in the next couple of week, but I cannot promise anything. To compile for windows store, just add "windows-api=store" to your b2 invocation. Regards, /M

3 11

Request for review: Boost.Fit
by paul Fultz 06 Oct '15

06 Oct '15

Hi All, Boost.Fit is a header-only function utility library for C++11. It supports both gcc, clang and visual studio. More info can be found here: https://github.com/pfultz2/Fit I would like to take this time to ask for a review. Vicente Botet has mentioned he could be a review manager. So I would like to move forward in scheduling a formal review. I plan to boostify the library for the formal review. In addition, I would like to ask for an informal review at this time. If anyone has some feedback or questions, that would be greatly appreciated. Thanks, Paul

6 10

Boost.GSL?
by David Sankel 05 Oct '15

05 Oct '15

As you may or may not know, Bjarne Stroustrup, Herb Sutter, and others have announced a new set of C++ guidelines[1] and an accompanying library[2] that supports them. For many folks, it would be difficult to incorporate a new library into their organizations, but there is a strong desire to make use of the guidelines. I floated the idea of including GSL in Boost as a distribution mechanism to Bjarne and he said he doesn't have any objection to the idea in principle, although he is hesitant to having to go through an extensive review process where some of these basic structures would change. What do you all think? Would it be appropriate and/or desirable to have a Boost.GSL library? -- David Sankel [1] https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md [2] https://github.com/Microsoft/GSL

9 16

Re: [boost] boost.test regression or behavior change (was Re: Boost.lockfree)
by Brian Wood 04 Oct '15

04 Oct '15

Bjorn Reese writes >On 10/04/2015 12:18 PM, Gennadiy Rozental wrote: > >> Sooner rather than later we should have this discussion and setup timeline. >> IMO it had very little sense to continue to maintain c++03 workarounds. >> Boost code should be an example how modern c++ libraries should look like. >> And c++03 compatibility is directly in a way of this goal. > > You appear to have missed the many discussions on this topic. > > While Boost started out to design cutting-edge libraries, it has been > caught by its own success. Today there is a large user-base that still > uses C++03, and that are unlikely to upgrade in the foreseeable future. > > Therefore, the current consensus is that existing libraries should not > increase their standards requirements. New libraries are free to decide > their standards requirements (although it will probably be questioned > during a formal review.) > Support for that is dwindling as more projects adopt 2011 or newer versions of C++. I understand Gennadiy and Raffi's desire to discuss this issue again. C++ 2011 is required to use my software. That decision was also based on limited resources and the belief that C++ 2011 had some helpful things for on line code generation. If I had more resources, I could support C++ 2003, but at this point I'm happy to not have to support that. As time goes on, more people are using C++ 2011 or newer. -- Brian Ebenezer Enterprises - In G-d we trust. http://webEbenezer.net

1 0

Boost perf tests?
by Stephan T. Lavavej 03 Oct '15

03 Oct '15

Hi Boost devs, Does Boost have any runtime perf tests? We (MSVC) are looking for something that uses modern C++, which would reveal areas where our optimizer and libraries could be improved. I looked around briefly, but didn't find anything. Thanks, STL

6 6

[optional] Specializing optional to save space
by David Stone 03 Oct '15

03 Oct '15

Andrzej posted another thread about creating a new compact_optional class. The goal of this class is to make it easy to create a new optional type with a special sentinel value. This allows easy customization per instance of an optional value. This post is about the opposite approach: making it easier to specialize optional to provide special behavior for all instances of a given optional type. When I bring this up, people often compare it to the vector<bool> specialization, but this is a completely different issue. The problem of vector<bool> is that it does not actually store a bool anywhere, so it cannot return a reference to one. This would still store a T somewhere. For the rest of the discussion, I will be assuming a typical standard library implementation on a 64-bit system. Whenever I talk about specific sizes of objects, mentally insert "on most common systems". The principles apply generally. Consider the case of optional<std::string>. Using the naive implementation, this object is 8 bytes larger than std::string, due to alignment requirements. However, there are certain representations of std::string that are not actually possible. For instance, for common implementations of std::string you cannot have std::string::size() == std::numeric_limits<std::string::size_type>::max() *. We can take advantage of this if our std::string implementation stores the capacity as an integer value, rather than a pointer to the end of the storage. Therefore, we could have implementations that look something like this: class string { friend optional<string>; }; template<> class optional<std::string> { optional(none_t) { // Use friendship to just set capacity to sentinel value } explicit operator bool() const { return m_data.capacity() == std::numeric_limits<std::string::size_type>::max(); } }; optional<std::string> still stores std::string in it, so operator*() works just fine. The initialized check is still just comparing a field against a compile-time constant. This makes this purely a space optimization that cannot be detected by the user, unless they use sizeof(optional<std::string>). I believe all of this is possible today with the current specification of boost::optional (and would definitely be allowed for the proposed std::experimental::optional). However, this requires the creator of each specialization to implement the full optional interface. What's more, it is especially tricky to specialize optional for a class template when you only want to specialize on certain specializations of the class template. My use case for this is my bounded::integer library. This library lets you specify the bounds of your integer as template parameters. If your bounded::integer has a narrower range than its underlying integer, you can take advantage of this to make a more space-efficient optional. If, however, the bounded::integer min and max are equal to that of the underlying type, there is no extra space and we want the default optional implementation. With the current specialization approach, it is the responsibility of the specializer to reimplement all of optional. A better approach to easily support this space optimization is as follows: optional contains an instance of optional_storage<value_type>. optional_storage has a much narrower interface: * optional_storage() leaves it uninitialized * optional_storage(in_place_t, T && ...) constructs the value directly with the variadic arguments * emplace(T && ...) constructs an object when there may be one in existence already * reset() destroys the contained object and sets the storage to uninitialized * is_initialized() says whether the contained object is initialized. This could be replaced with explicit operator bool(); I have no preference. * value() returns a reference to the value We need both the constructor and the emplace function to allow literal optional types. This is because for the general case, emplace calls placement new, which is not allowed in a constexpr function. This solves the problem of specializers having to implement the entire interface of optional just to change how the uninitialized state is stored. However, it still does not solve the problem I mentioned earlier about allowing easy use of the default storage policy for some specializations of your own class template. To solve that, we need one more class: default_optional_storage. default_optional_storage<T> is a literal type if T is a literal type (in practice, std::is_trivially_destructible<T>::value is all you really need to test). It implements the same interface as optional_storage<T>. The default implementation of optional_storage<T> is template<typename T> struct optional_storage : default_optional_storage<T> { private: using base = default_optional_storage<T>; public: using base::base; }; This means that the optional library would have at least three classes in its public interface: * optional * optional_storage * default_optional_storage To see a working example of this (including a specialization for bounded::integer), see https://bitbucket.org/davidstone/bounded_integer/src/2defec41add2079ba023c2… https://bitbucket.org/davidstone/bounded_integer/src/2defec41add2079ba023c2… * The reason is that std::string::size_type is a typedef for std::size_t, which is equivalent in range to std::uint64_t. However, std::iterator_traits<std::string::iterator>::difference_type is std::ptrdiff_t, which is equivalent in range to std::int64_t. This means that for the largest std::string, std::distance(begin(), end()) cannot be more than std::numeric_limits<std::ptrdiff_t>::max(), which is less than std::numeric_limits<std::size_t>::max().

6 15

[type_traits] common_type errors with Oracle compiler
by Andrey Semashev 03 Oct '15

03 Oct '15

Hi, Both oracle-intel-S2-next-cpp11 and oracle-sparc-S2-next-stlport4 testers fail to compile common_type as it is being used in Boost.Chrono. This in turn affects compilation of Boost.Thread and multiple other library tests. The error can be seen here: http://www.boost.org/development/tests/develop/developer/output/oracle-inte… Just in case if the test results go down, I'm copying the error inline below. Could it be fixed? "CC" -std=c++11 -temp=/tmp/bn -xO4 -mt -erroff=%none -m32 -KPIC -DBOOST_ALL_NO_LIB=1 -DBOOST_ATOMIC_DYN_LINK=1 -DBOOST_CHRONO_DYN_LINK=1 -DBOOST_SYSTEM_DYN_LINK=1 -DBOOST_SYSTEM_NO_DEPRECATED -DBOOST_THREAD_BUILD_DLL=1 -DBOOST_THREAD_POSIX -DBOOST_THREAD_USE_DLL=1 -DNDEBUG -D__typeof__=__typeof__ -I".." -c -o "/export/home/sstrunk-tester/boost_regression/boost_regression_develop/boost_intel-S2_cpp11/results/boost/bin.v2/libs/atomic/test/atomicity.test/sun-next_cpp11/release/threading-multi/atomicity.o" "../libs/atomic/test/atomicity.cpp" "../boost/chrono/duration.hpp", line 405: Error: type is not a member of boost::common_type<long long, long long>. "../boost/thread/pthread/timespec.hpp", line 52: Where: While specializing "boost::common_type<boost::chrono::duration<long long, boost::ratio<1, 1000000000>>, boost::chrono::duration<long long, boost::ratio<1, 1>>>". "../boost/thread/pthread/timespec.hpp", line 52: Where: Instantiated from boost::chrono::operator-<Rep1, Period1, Rep2, Period2>(const duration<Rep1, Period1>&, const duration<Rep2, Period2>&). "../boost/thread/pthread/timespec.hpp", line 52: Where: Instantiated from non-template code. "../boost/chrono/duration.hpp", line 406: Error: A declaration does not specify a tag or an identifier. "../boost/thread/pthread/timespec.hpp", line 52: Where: While specializing "boost::common_type<boost::chrono::duration<long long, boost::ratio<1, 1000000000>>, boost::chrono::duration<long long, boost::ratio<1, 1>>>". "../boost/thread/pthread/timespec.hpp", line 52: Where: Instantiated from boost::chrono::operator-<Rep1, Period1, Rep2, Period2>(const duration<Rep1, Period1>&, const duration<Rep2, Period2>&). "../boost/thread/pthread/timespec.hpp", line 52: Where: Instantiated from non-template code. "../boost/chrono/duration.hpp", line 406: Error: Use ";" to terminate declarations. "../boost/thread/pthread/timespec.hpp", line 52: Where: While specializing "boost::common_type<boost::chrono::duration<long long, boost::ratio<1, 1000000000>>, boost::chrono::duration<long long, boost::ratio<1, 1>>>". "../boost/thread/pthread/timespec.hpp", line 52: Where: Instantiated from boost::chrono::operator-<Rep1, Period1, Rep2, Period2>(const duration<Rep1, Period1>&, const duration<Rep2, Period2>&). "../boost/thread/pthread/timespec.hpp", line 52: Where: Instantiated from non-template code. "../boost/chrono/duration.hpp", line 406: Error: "}" expected instead of ">". "../boost/thread/pthread/timespec.hpp", line 52: Where: While specializing "boost::common_type<boost::chrono::duration<long long, boost::ratio<1, 1000000000>>, boost::chrono::duration<long long, boost::ratio<1, 1>>>". "../boost/thread/pthread/timespec.hpp", line 52: Where: Instantiated from boost::chrono::operator-<Rep1, Period1, Rep2, Period2>(const duration<Rep1, Period1>&, const duration<Rep2, Period2>&). "../boost/thread/pthread/timespec.hpp", line 52: Where: Instantiated from non-template code. "../boost/thread/pthread/timespec.hpp", line 52: Error: The operation "const boost::chrono::duration<long long, boost::ratio<1, 1000000000>> - boost::chrono::duration<long long, boost::ratio<1, 1>>" is illegal. 5 Error(s) detected.

3 4

Compiler warnings after boost update
by Auer, Jens 03 Oct '15

03 Oct '15

Hi, we compile with high compiler warnings setting (-Wall, -Wpedantic), and treat compiler warnings as errors. Recently, I had to upgrade the boost library version from 1.53 to at least 1.55. Since there was no package available, I compiled it by hand from the source code. With 1.53, everything compiled fine, but with the newer version my builds now break because the boost library generates a lot of warnings, e.g. /cots/boost-1.55/include/boost/iterator/iterator_concepts.hpp: At global scope: /cots/boost-1.55/include/boost/mpl/assert.hpp:288:54: error: use of old-style cast [-Werror=old-style-cast] boost::mpl::assert_arg( (void (*) pred)0, 1 ) \ ^ /cots/boost-1.55/include/boost/mpl/assert.hpp:59:58: note: in definition of macro ‘BOOST_MPL_AUX_ASSERT_CONSTANT’ # define BOOST_MPL_AUX_ASSERT_CONSTANT(T, expr) enum { expr } /cots/boost-1.55/include/boost/range/algorithm/equal.hpp: In function ‘bool boost::range::equal(const SinglePassRange1&, const SinglePassRange2&, BinaryPredicate)’: /cots/boost-1.55/include/boost/concept/detail/general.hpp:71:20: error: typedef ‘boost_concept_check185’ locally defined but not used [-Werror=unused-local-typedefs] BOOST_PP_CAT(boost_concept_check,__LINE__) /cots/boost-1.55/include/boost/property_tree/xml_parser.hpp:52:59: required from ‘void boost::property_tree::xml_parser::read_xml(std::basic_istream<typename Ptree::key_type::value_type>&, Ptree&, int) [with Ptree = boost::property_tree::basic_ptree<std::basic_string<char>, std::basic_string<char> >; typename Ptree::key_type::value_type = char; typename Ptree::key_type::value_type = char]’ /home/auerj/MDAF/src/commons/src/crypto/KeyFileReader.cpp:43:34: required from here /cots/boost-1.55/include/boost/property_tree/detail/rapidxml.hpp:1204:33: error: zero as null pointer constant [-Werror=zero-as-null-pointer-constant] if (first_attribute()) ^ /cots/boost-1.55/include/boost/property_tree/detail/rapidxml.hpp:1204:33: error: zero as null pointer constant [-Werror=zero-as-null-pointer-constant] /cots/boost-1.55/include/boost/property_tree/detail/rapidxml.hpp:1211:45: error: zero as null pointer constant [-Werror=zero-as-null-pointer-constant] These are just some examples, there are literally hundreds of warnings. It is enough to just include ptree.hpp, but other headers have the same issue. I am wondering why this came up after the update. Is it a configuration problem during the build of the boost libraries, or is it an issue in the boost libraries? I find it hard to believe that the code quality changed so much between the versions. What is the policy of the boost project concerning compiler warnings in installation headers? I would assume that the libraries should compile without warnings on supported compilers, either because there are no issues, or because warnings are disabled in the boost headers. Best wishes, Jens -- Jens Auer | CGI | Software-Engineer CGI (Germany) GmbH & Co. KG Rheinstraße 95 | 64295 Darmstadt | Germany T: +49 6151 36860 154 jens.auer(a)cgi.com<mailto:jens.auer@cgi.com> Unsere Pflichtangaben gemäß § 35a GmbHG / §§ 161, 125a HGB finden Sie unter de.cgi.com/pflichtangaben<http://de.cgi.com/pflichtangaben>. CONFIDENTIALITY NOTICE: Proprietary/Confidential information belonging to CGI Group Inc. and its affiliates may be contained in this message. If you are not a recipient indicated or intended in this message (or responsible for delivery of this message to such person), or you think for any reason that this message may have been addressed to you in error, you may not use or copy or deliver this message to anyone else. In such case, you should destroy this message and are asked to notify the sender by reply e-mail.

10 14

[build][regression] Problems when trying to run automated regression tests for MSVC-7.1
by Ion Gaztañaga 03 Oct '15

03 Oct '15

Hi, Since Boost 1.55 minimum requirements include Visual C++ 2003. Since currently there is no regression report for this compiler, I'm trying to follow the steps detailed here and try to fill the gap: http://www.boost.org/development/running_regression_tests.html All the source code is downloaded, my user-config.jam only contains "using msvc ;" but it seems that Boost.Build continues to be broken for MSVC-7.1: <output> notice: Loading user-config configuration file 'user-config.jam' from 'C:/Users/igaztanaga'. notice: [msvc-cfg] msvc-7.1 detected, command: 'C:\Program Files (x86)\Microsoft Visual Studio .NET 2003\Vc7\bin\cl.exe' notice: will use 'C:\Program Files (x86)\Microsoft Visual Studio .NET 2003\Vc7\bin\cl.exe' for msvc, condition <toolset>msvc-7.1 C:/boost/develop/boost_bb/src/tools\msvc.jam:1072: in configure-really *** argument error * rule generate-setup-cmd ( version : command : parent : options * : cpu : global-setup : default-global-setup-options : default-setup ) * called with: ( 7.1 : C:\Program Files (x86)\Microsoft Visual Studio .NET 2003\Vc7\bin : C:\Program Files (x86)\Microsoft Visual Studio .NET 2003\Vc7 : <command>C:\Program Files (x86)\Microsoft Visual Studio .NET 2003\Vc7\bin\cl.exe : i386 : : x86 : vcvars32.bat ) * missing argument global-setup C:/boost/develop/boost_bb/src/tools\msvc.jam:798:see definition of rule 'generate-setup-cmd' being called C:/boost/develop/boost_bb/src/tools\msvc.jam:201: in configure C:/boost/develop/boost_bb/src/tools\msvc.jam:153: in msvc.init C:/boost/develop/boost_bb/src/build\toolset.jam:43: in using C:\Users\igaztanaga\user-config.jam:49: in modules.load c:/boost/develop/boost_bb/src\build-system.jam:249: in load-config c:/boost/develop/boost_bb/src\build-system.jam:389: in load-configuration-files c:/boost/develop/boost_bb/src\build-system.jam:524: in load C:\boost\develop\boost_bb\src/kernel\modules.jam:295: in import C:\boost\develop\boost_bb\src/kernel/bootstrap.jam:139: in boost-build C:\boost\develop\boost_regression\boost-build.jam:57: in module scope </output> I can't figure out what's wrong in msvc.jam. Comments on that file suggest that MSVC-7.1 should be supported although it seems that since MSVC-8.0 the configuration script architecture changed. I'd be glad if any Boost.Build expert could have a look at this issue. Many thanks, Ion PS: Full output for command... python run.py --runner=igaztanaga --toolsets=msvc-7.1 --tag=develop --incremental --libraries=move --have-source > output.txt ...attached.

2 4

compact_optional -- prompting interest
by Andrzej Krzemienski 02 Oct '15

02 Oct '15

Hi Everyone, I would like to inquire if there would be an interest in Boost in another library for storing optional objects, but working under different design goals. Compact optional T has (or can have) the same sizeof as T. It uses one indicated value of T to represent the "empty" (or "singular") value. You can declare it like this: compact_optional<evp_int<int, -1>> oi; This reads: we have an optional int, with type int inside, where -1 represents the empty value. It can never have a genuine (non-empty value -1). This can be used, for instance, to wrap the std::string::npos into: compact_optional<evp_int<string::size_type, string::npos>> With the same memory layout as std::string::size_type, but with the special syntax for managing the singular value. It is not meant to be an alternative to Boost.Optional: it targets a different application space. The (single-header) implementation is at: https://github.com/akrzemi1/compact_optional The documentation is at: https://github.com/akrzemi1/compact_optional/blob/master/documentation.md For the motivation and design rationale see this article: https://akrzemi1.wordpress.com/2015/07/15/efficient-optional-values/ Any feedback is welcome. Regards, &rzej

17 43

[build] Issue with -- argument
by Gennadiy Rozental 01 Oct '15

01 Oct '15

Hi, Due to the change in Boost.Test parameter handling I needed update Boost.Test Jamfile, since I was passing baseline pattern file names as arguments to the test module. Here is snippet from my Jamfile: return [ $(test-rule) $(source_files) ../build//$(usage-variant) $(extra-libs) : -- <============= Note: I added '--' : $(pattern_file) ... Unfortunately -- disappears for some reason from command line. I found that the following works: return [ $(test-rule) $(source_files) ../build//$(usage-variant) $(extra-libs) : -- "" <============= Note "" : $(pattern_file) ... Can we fix it so that "" is not required? Is there a different workaround? Gennadiy

1 0

Re: [boost] [regression] Tests for 'develop' not showing
by Tom Kent 30 Sep '15

30 Sep '15

On Wed, Sep 23, 2015 at 8:16 AM, Tom Kent <lists(a)teeks99.com> wrote: > > On Tue, Sep 22, 2015 at 9:53 PM, Rene Rivera <grafikrobot(a)gmail.com> > wrote: >> >> > On Wed, Sep 9, 2015 at 4:35 PM Edward Diener <eldiener(a)tropicsoft.com> >>>> > wrote: >>>> > >>>> > > Trying >>>> > > >>>> http://www.boost.org/development/tests/develop/developer/summary.html I >>>> > > get: >>>> > > >>>> > > "Error extracting file: The specified zipfile was not found." >>>> > > >>>> >>>> And they are messed up again. Tom can you look into your side of this? >> When I generated the results I got the ZIP files to be 1.5GiB and 2.0GiB, >> approximately, for develop and master, respectively. Yet what I see on the >> web site now is 1.5GiB and 200MiB. Which is clearly incorrect. And it's >> precisely the shorter ZIP, i.e. master.zip, that now doesn't work. I.e >> browsing develop results works, but not browsing master results. >> > > Over the last week I've seen both the master and develop results showing > the zip error message. > > I just noticed that in the last master run, I had a segfault in the > processing: > > tomkent@eddie:~/tmp/boost_reports/boost-reports⟫ tail master.log > Reading failures markup > Reading > /home/tomkent/tmp/boost_reports/boost-reports/master/incoming/master/processed/BP > x86_64 C++11.xml > Merging expected results > Generating links pages > Reading > /home/tomkent/tmp/boost_reports/boost-reports/master/incoming/master/processed/CrystaX.NET-apilevel-19-armeabi-v7a-hard.xml > Merging expected results > Generating links pages > Reading > /home/tomkent/tmp/boost_reports/boost-reports/master/incoming/master/processed/CrystaX.NET-apilevel-19-armeabi-v7a.xml > Merging expected results > Segmentation fault (core dumped) > > I'll look into it more tonight. > Tom > It looks like running the reports (esp master) is taking much longer...up to 2hrs. I had a cron job running every hour, which corrupted things when it was kicked off a second time while the first was still running. I've made a change in the script to setup a lock file, so that only one instance will run and submitted a pull request against the regression repo. It's already running on my report generator, so hopefully the problem won't show up again. If anyone sees it please let me know. Tom

4 6

[git] Testing and Pushing updates to library
by Artyom Beilis 30 Sep '15

30 Sep '15

Hello, I'm back to Boost after my last commits were in svn and now I need to make sure I do stuff correctly in git/github. In boost-svn there were trunk for development and release for up-to date release, currently master is what "release branch" is svn was and develop is what trunk? Q: Is it correct. I have several fixes - I pushed them to master branch of Boost.Locale library. https://github.com/boostorg/locale/compare/26482aa844...ea55386441 I did same for develop (I hope correctly) Q: Is pushing changes to master it enough to get them into next boost release? I had some strange behavior of "detached Head" so I needed to create small temporary local branch and than merge it to master... Q: is it normal? Can't I commit/push directly to master without temporary branch? Testing - in svn there were regression tests for both release and trunk branches of svn... Q: What happens now with regression tests I cound't find the information in the wiki. Thanks. Artyom Beilis -------------- CppCMS - C++ Web Framework: http://cppcms.com/ CppDB - C++ SQL Connectivity: http://cppcms.com/sql/cppdb/

2 1

how to pass -std=c++14 to b2 while building boost libraries
by Frédéric Bron 30 Sep '15

30 Sep '15

Hi, I would like to build a c++14 version of boost libraries on my system. I have the intel compiler (15.0.3) on a x86_64 linux machine (2.6.32-279.19.1.el6.x86_64). I do the following: 1. build b2 CC="icc" CFLAGS="-O2 -DNDEBUG -xhost" CXX="icpc" CXXFLAGS="-O2 -DNDEBUG -xhost -std=c++14" AR="ar" AS="as" RANLIB="ranlib" ./bootstrap.sh --without-icu --prefix=/myusr/icc-15.0.3-c++14-release/boost --with-toolset=intel-linux 2. edit user-config.jam My user-config.jam, located in the boost source directory contains: using intel-linux : : icpc : <compilerflags>-xhost <compilerflags>-std=c++14 ; 3. run b2 ./b2 -d2 -j16 -sBZIP2_INCLUDE=/myusr/icc-15.0.3-c++14-release/bzip2/include -sBZIP2_LIBPATH=/myusr/icc-15.0.3-c++14-release/bzip2/lib -sZLIB_INCLUDE=/myusr/icc-15.0.3-c++14-release/zlib/include -sZLIB_LIBPATH=/myusr/icc-15.0.3-c++14-release/zlib/lib --layout=system --user-config=user-config.jam --without-mpi --without-python --without-context --without-coroutine link=static threading=multi runtime-link=shared target-os=linux address-model=64 variant=release install The problem I see is that the flag -std=c++14 is not passed to the compiler. For example, this is an output of b2: "icpc" -c -xc++ -w1 -inline-level=2 -O3 -ip -pthread -m64 -DBOOST_ALL_NO_LIB=1 -DBOOST_FILESYSTEM_STATIC_LINK=1 -DBOOST_SYSTEM_STATIC_LINK=1 -DNDEBUG -I"." -c -o "bin.v2/libs/filesystem/build/intel-linux/release/link-static/threading-multi/codecvt_error_category.o" "libs/filesystem/src/codecvt_error_category.cpp" no trace of -std=c++14 flag. How can I send that flag to the compiler? Apparently, the problem is the same when using g++ 5.2.0. Frédéric

2 2

[boost.build] broken link
by Frédéric Bron 30 Sep '15

30 Sep '15

On this page: http://www.boost.org/doc/libs/1_59_0/tools/build/index.html the link to the documentation is broken: http://www.boost.org/doc/libs/1_59_0/tools/build/doc/html/index.html error message: 404 Not Found File "/home/www/live.boost.org/common/code/../../doc/archives/boost_1_59_0/tools/build/doc/html/index.html" not found. Unable to find file. Cheers, Frédéric

2 1

develop tests
by Robert Ramey 29 Sep '15

29 Sep '15

When I try to look at the tests of the develop branch at http://www.boost.org/development/tests/develop/developer/serialization.html I get an error message. Has this been resolved yet? Is there anything I have to do? Robert Ramey

1 0

Variadics bug in MSVC-12.0
by Gennadiy Rozental 29 Sep '15

29 Sep '15

Hi, While working on improving of implementation of data driven tests, I found rather annoying bug in MSVC-12.0 with variadic templates. The code seems to work fine with msvc-14.0, gcc 4.8 and clang 3.4. I did not try msvc- 13.0. Does anyone know a workaround? Example follows (try to comment on/off line: auto const& t3). Gennadiy // C++ 14 index_sequence template <std::size_t... Ns> struct index_sequence {}; template<typename IS1, typename IS2> struct merge_index_sequence; template <std::size_t... Ns1, std::size_t... Ns2> struct merge_index_sequence<index_sequence<Ns1...>, index_sequence<Ns2...>> { typedef index_sequence<Ns1..., Ns2...> type; }; template <std::size_t B, std::size_t E, typename Enabler = void> struct make_index_sequence { typedef typename merge_index_sequence< typename make_index_sequence<B, (B + E)/2>::type, typename make_index_sequence<(B + E)/2, E>::type>::type type; }; template <std::size_t B, std::size_t E> struct make_index_sequence<B, E, typename std::enable_if<E == B + 1, void>::type> { typedef index_sequence<B> type; }; template <typename... T> using index_sequence_for = typename make_index_sequence<0, sizeof...(T)>::type; ////////////////////////////////////////////////////////////////////////// template<typename T1, typename T2> struct merged_tuple { typedef std::tuple<T1,T2> type; typedef std::tuple<T1 const&,T2 const&> ref; }; template<typename T1, typename ...T> struct merged_tuple<T1, std::tuple<T...>> { typedef std::tuple<T1, T...> type; typedef std::tuple<T1 const&, T const&...> ref; }; template<typename ...T, typename T1> struct merged_tuple<std::tuple<T...>, T1> { typedef std::tuple<T..., T1> type; typedef std::tuple<T const&..., T1 const&> ref; }; template<typename ...T1, typename ...T2> struct merged_tuple<std::tuple<T1...>, std::tuple<T2...>> { typedef std::tuple<T1..., T2...> type; typedef std::tuple<T1 const&..., T2 const&...> ref; }; template<typename ...T1, typename ...T2, std::size_t ...I1, std::size_t ...I2> inline typename merged_tuple<std::tuple<T1...>, std::tuple<T2...>>::ref tuple_merge_impl( std::tuple<T1 const&...> const& a1, std::tuple<T2 const&...> const& a2, index_sequence<I1...> const& , index_sequence<I2...> const& ) { using ref_type = typename merged_tuple<std::tuple<T1...>, std::tuple<T2...>>::ref; return ref_type( std::get<I1>(a1)..., std::get<I2>(a2)... ); } template<typename ...T1, typename ...T2> inline typename merged_tuple<std::tuple<T1...>, std::tuple<T2...>>::ref tuple_merge_impl( std::tuple<T1 const&...> const& a1, std::tuple<T2 const&...> const& a2 ) { return tuple_merge_impl( a1, a2, index_sequence_for<T1...>{}, index_sequence_for<T2...>{} ); } template<typename T> inline std::tuple<T const&> as_tuple( T const& arg ) { return std::tuple<T const&>( arg ); } template<typename ...T> inline std::tuple<T...> const& as_tuple( std::tuple<T...> const& arg ) { return arg; } template<typename T1, typename T2> inline typename merged_tuple<T1, T2>::ref tuple_merge( T1 const& a1, T2 const& a2 ) { return tuple_merge_impl( as_tuple( a1 ), as_tuple( a2 ) ); } int main() { auto const& t1 = tuple_merge( 1, 2 ); auto const& t2 = tuple_merge( 3, 4 ); auto const& t3 = tuple_merge( t1, 5 ); auto const& t4 = tuple_merge( 6, t2 ); return 0; }

1 0

Boost.Test: runtime parameter framework update
by Gennadiy Rozental 29 Sep '15

29 Sep '15

Hi, Over the years there were complains about the interface and functionality of the Boost.Test Unit Test Framework(UTF)'s runtime parameters. Primarily command line arguments handling, but also documentation and few other concerns. This update addresses all these issues, introduces few new features and makes runtime parameters much more user friendly. In addition new implementation significantly simpler. Here is short summary of fixed issues and significant new features: * (new) UTF now requires all user defined arguments to follow UTF specific arguments. They are separated by "--" marker. For example: test.exe --random -- /myarg:17 * (bug) UTF now properly supports arguments with spaces. For example: test.exe --log_sink="file name.txt" * (bug) UTF now reports missing value in arguments. For example: test.exe --log_sink=, produces: Missing an argument value for the parameter log_level in the argument -- log_level= * (bug/new) UTF now reports invalid parameters. Moreover, UTF now supports hints with possible typos. For example: test.exe --colour, produces: An unrecognized parameter in the argument --colour Did you mean one of these? color_output Suggestion is shown when close (1 char distance from unambiguous parameter name) exists. * (new) UTF now report possible ambiguous parameters. For example: test.exe --log=all, produces: An ambiguous parameter name in the argument --log=all Did you mean one of these? log_format log_level log_sink * (new) UTF parameter help now accepts optional parameter name. Moreover you can actually "guess" the name by providing just unambiguous prefix. In this case it shows detailed information about requested parameter, including semantic, possible values and formats. For example: test.exe --help=list_con, produces: Parameter: list_content Lists the content of test tree - names of all test suites and test cases. Command line formats: --list_content[=<HRF|DOT>] Environment variable: BOOST_TEST_LIST_CONTENT Parameter list_content instructs the framework to list the content of the test module instead of executing the test cases. Parameter accepts optional string value indicating the format of the output. Currently the framework supports two formats: human readable format (HRF) and dot graph format (DOT). If value is omitted HRF value is assumed. The changes will be released with next release of boost. Any comments are welcome. Gennadiy

1 0

Graphical debugging extension for VS2015 (Container, Geometry, Polygon, Variant, ...)
by Adam Wulkiewicz 29 Sep '15

29 Sep '15

Hi, For some time now I've been thinking about extending the capabilities of a debugger and to visualize data in more convenient way than the raw numbers. It's obvious to me that in many cases variables could be graphically visualized, in many cases this is the "natural" representation, this would greately simplify the debugging. I haven't found anything like it so I've decided to play with the VS2015 extensions, mostly because they're easy to write. This is what I came up with (see the readme): https://github.com/awulkiew/graphical-debugging Besides adding commonly used native visualizers for types from some Boost libraries it allows to display their graphical representation. The extension support Boost.Geometry models and other types used internally in this library, Boost.Polygon models (polygon_set_data is missing) and boost::variant storing geometries. As a bonus, it's possible to watch containers of values (some STL containers as well as boost::array and contiguous containers from Boost.Container) as charts. Maybe if there were enough interest it'd be worth to extend it and/or to add to the official VS extensions gallery. I'm a Boost.Geometry developer so in the future I plan to support all of the coordinate systems supported by the library, maybe other internals and basically anything that helps me with the development. But I can imagine that variables of types from various Boost libraries could also be visualized, e.g. Polygon's voronoi diagram and internals, Math's quaternions as 3D Axis-Angle, std::complex as a point on a plane, containers of complex numbers and in general arbitrary types represented somehow as a 1D, 2D or 3D objects, CircularBuffer e.g. as a pie chart, BGL's graphs, maybe GIL's images, Interprocess' shared memory blocks?, etc. So feel free to share suggestions and contribute if you like. Regards, Adam

3 5

Trying out CLion.. Free license..
by Rene Rivera 29 Sep '15

29 Sep '15

As some of you are aware JetBrains recently release a new IDE that has some rather cool features (re: <https://www.jetbrains.com/clion/>) for C++ programmers. I am personally interested in using CLion for Boost work. In particular I'm hoping to write a CLion plug-in that integrates Boost Build into the IDE. And hence I've have taken it upon myself to arrange for Boost developers to get licenses for library authors to use, if they so wish. If you are interested in getting a CLion license and are a current Boost Library author here's what I need: * An email from you requesting that you want a license. * In that email indicate which Boost libraries you are an author, or maintainer, of. * Send the email from an account that you want me to send you the license when we get it. I want to avoid having to update email information a year from now when I need to renew the licenses. * You have until the end of this week, roughly, to send that email. I'll collect that and request the Boost licenses from JetBrains. And "pass" them out with instructions as needed. Rene. -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net -- rrivera/acm.org (msn) - grafikrobot/aim,yahoo,skype,efnet,gmail

6 7

CLion plug-in for Boost.Build (was: Trying out CLion.. Free license..)
by Mateusz Loskot 28 Sep '15

28 Sep '15

On 28 September 2015 at 21:19, Rene Rivera <grafikrobot(a)gmail.com> wrote: > On Mon, Sep 28, 2015 at 2:14 PM, Robert Ramey <ramey(a)rrsd.com> wrote: >> On 9/28/15 11:45 AM, Rene Rivera wrote: >> >>> As some of you are aware JetBrains recently release a new IDE that has >>> some >>> rather cool features (re: <https://www.jetbrains.com/clion/>) for C++ >>> programmers. I am personally interested in using CLion for Boost work. In >>> particular I'm hoping to write a CLion plug-in that integrates Boost Build >>> into the IDE. And hence I've have taken it upon myself to arrange for >>> Boost >>> developers to get licenses for library authors to use, if they so wish. >>> >> >> Hmm - wouldn't it be easier just to use CMake. You wouldn't have to write >> any plugin. The serialization library includes CMake files for that >> library's build and test and it works quite well. >> > > IMO no.. But I know that opinions differ ;-) Some time ago, I developed basic Boost.Build plugin for Qt Creator https://github.com/mloskot/qt-creator-plugin-boostbuild/ which interacts with the b2.exe command line. At that time, I also briefely discussed some API ideas with Volodya. Later, Volodya implemented the Boost.Build API and server mode http://lists.boost.org/boost-build/2015/03/27906.php May I ask, which option are you going to choose for your plugin? Is it going to be the command line approach, the new BB API or anything else? Best regards, -- Mateusz Loskot, http://mateusz.loskot.net

2 2

[test] Regression - overloaded virtual function "boost::unit_test::test_observer::test_unit_skipped" is only partially overridden
by Vicente J. Botet Escriba 25 Sep '15

25 Sep '15

Hi, there is a regression in Boost.Test. Test output: boost/bin.v2/libs/test/build/intel-linux/release/link-static/threading-multi Rev 32fc9643eb674d60616412bb427bb6e0f0300cc0 / Thu, 24 Sep 2015 19:13:08 +0000 Compile [2015-09-24 20:55:11 UTC]: succeed "icpc" -c -xc++ -w2 -inline-level=2 -O3 -ip -pthread -m64 -DBOOST_ALL_NO_LIB=1 -DBOOST_CHRONO_STATIC_LINK=1 -DBOOST_SYSTEM_NO_DEPRECATED -DBOOST_SYSTEM_STATIC_LINK=1 -DBOOST_TIMER_STATIC_LINK=1 -DNDEBUG -I".." -c -o "/boosttest/develop/results/boost/bin.v2/libs/test/build/intel-linux/release/link-static/threading-multi/test_tools.o" "../libs/test/src/test_tools.cpp" In file included from ../boost/test/impl/test_tools.ipp(19), from ../libs/test/src/test_tools.cpp(16): ../boost/test/unit_test_log.hpp(88): warning #654: overloaded virtual function "boost::unit_test::test_observer::test_unit_skipped" is only partially overridden in class "boost::unit_test::unit_test_log_t" class BOOST_TEST_DECL unit_test_log_t : public test_observer, public singleton<unit_test_log_t> { ^ remark #11074: Inlining inhibited by limit max-size remark #11074: Inlining inhibited by limit max-total-size remark #11076: To get full report use -qopt-report=4 -qopt-report-phase ipo Vicente

1 0

boost_1_59_0 build failures
by Karen Shaeffer 24 Sep '15

24 Sep '15

Hello, I downloaded boost_1_59_0 and built the whole set of libraries. gcc --version gcc (Ubuntu 4.8.4-2ubuntu1~14.04) 4.8.4 ./b2 install warning: No toolsets are configured. warning: Configuring default toolset "gcc". warning: If the default is wrong, your build may not work correctly. warning: Use the "toolset=xxxxx" option to override our guess. warning: For more configuration options, please consult warning: http://boost.org/boost-build2/doc/html/bbv2/advanced/configuration.html Performing configuration checks - 32-bit : no (cached) - 64-bit : yes (cached) - arm : no (cached) - mips1 : no (cached) - power : no (cached) - sparc : no (cached) - x86 : yes (cached) - symlinks supported : yes (cached) - lockfree boost::atomic_flag : yes (cached) - has_icu builds : yes (cached) warning: Graph library does not contain MPI-based parallel components. note: to enable them, add "using mpi ;" to your user-config.jam - zlib : yes (cached) - iconv (libc) : yes (cached) - icu : yes (cached) - compiler-supports-visibility : yes (cached) - compiler-supports-ssse3 : yes (cached) - compiler-supports-avx2 : yes (cached) - gcc visibility : yes (cached) - long double support : yes (cached) warning: skipping optional Message Passing Interface (MPI) library. note: to enable MPI support, add "using mpi ;" to user-config.jam. note: to suppress this message, pass "--without-mpi" to bjam. note: otherwise, you can safely ignore this message. - zlib : yes (cached) Component configuration: - atomic : building - chrono : building - container : building - context : building - coroutine : building - coroutine2 : building - date_time : building - exception : building - filesystem : building - graph : building - graph_parallel : building - iostreams : building - locale : building - log : building - math : building - mpi : building - program_options : building - python : building - random : building - regex : building - serialization : building - signals : building - system : building - test : building - thread : building - timer : building - wave : building ...patience... ...patience... ...patience... ...patience... ...patience... ...patience... ...found 34509 targets... ...updating 8 targets... gcc.compile.c++ bin.v2/libs/iostreams/build/gcc-4.8/release/link-static/threading-multi/bzip2.o libs/iostreams/src/bzip2.cpp:20:56: fatal error: bzlib.h: No such file or directory #include "bzlib.h" // Julian Seward's "bzip.h" header. ^ compilation terminated. "g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -pthread -m64 -DBOOST_ALL_NO_LIB=1 -DBOOST_IOSTREAMS_USE_DEPRECATED -DNDEBUG -I"." -c -o "bin.v2/libs/iostreams/build/gcc-4.8/release/link-static/threading-multi/bzip2.o" "libs/iostreams/src/bzip2.cpp" ...failed gcc.compile.c++ bin.v2/libs/iostreams/build/gcc-4.8/release/link-static/threading-multi/bzip2.o... ...skipped <pbin.v2/libs/iostreams/build/gcc-4.8/release/link-static/threading-multi>libboost_iostreams.a(clean) for lack of <pbin.v2/libs/iostreams/build/gcc-4.8/release/link-static/threading-multi>bzip2.o... ...skipped <pbin.v2/libs/iostreams/build/gcc-4.8/release/link-static/threading-multi>libboost_iostreams.a for lack of <pbin.v2/libs/iostreams/build/gcc-4.8/release/link-static/threading-multi>bzip2.o... ...skipped <p/usr/local/lib>libboost_iostreams.a for lack of <pbin.v2/libs/iostreams/build/gcc-4.8/release/link-static/threading-multi>libboost_iostreams.a... gcc.compile.c++ bin.v2/libs/iostreams/build/gcc-4.8/release/threading-multi/bzip2.o libs/iostreams/src/bzip2.cpp:20:56: fatal error: bzlib.h: No such file or directory #include "bzlib.h" // Julian Seward's "bzip.h" header. ^ compilation terminated. "g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -pthread -fPIC -m64 -DBOOST_ALL_NO_LIB=1 -DBOOST_IOSTREAMS_DYN_LINK=1 -DBOOST_IOSTREAMS_USE_DEPRECATED -DNDEBUG -I"." -c -o "bin.v2/libs/iostreams/build/gcc-4.8/release/threading-multi/bzip2.o" "libs/iostreams/src/bzip2.cpp" ...failed gcc.compile.c++ bin.v2/libs/iostreams/build/gcc-4.8/release/threading-multi/bzip2.o... ...skipped <pbin.v2/libs/iostreams/build/gcc-4.8/release/threading-multi>libboost_iostreams.so.1.59.0 for lack of <pbin.v2/libs/iostreams/build/gcc-4.8/release/threading-multi>bzip2.o... ...skipped <p/usr/local/lib>libboost_iostreams.so.1.59.0 for lack of <pbin.v2/libs/iostreams/build/gcc-4.8/release/threading-multi>libboost_iostreams.so.1.59.0... ...skipped <p/usr/local/lib>libboost_iostreams.so for lack of <p/usr/local/lib>libboost_iostreams.so.1.59.0... ...failed updating 2 targets... ...skipped 6 targets... Is that expected? thanks, Karen -- Karen Shaeffer Be aware: If you see an obstacle in your path, Neuralscape Services that obstacle is your path. Zen proverb

2 1

Fwd: [sort][container] Challenge for sorting experts, an improved stable sort
by Francisco José Tapia 23 Sep '15

23 Sep '15

Hi Jon, If the elements in the flat associative container are sorted, you need only to sort the elements to insert and after do a fusion of the two parts. If your container admit repeated elements, you can use the std::sort, if not, you must use an stable sort , and delete the repeated. You have several algorithms for to do a stable sort. In the library we are developing (https://github.com/fjtapia/sort_parallel ) you have a smart_merge_sort, which is a very fast stable sort and use only one half of the memory used by the data, is exception safe and use the move semantics I didn't see any implementation of the stable sort algorithms without additional memory, in any library GCC, TBB, IPP … I suppose because they are slow. If you have 100 elements and want to insert 30 elements, need to resize the vector to 130 elements, the last 30 are empty. If you have other vector with the data to insert, you can use smart_merge_sort, and use as auxiliary memory the last 15 elements of the main vector. After sort, delete the repeated elements. And with the two vectors you must do a half_merge fusion , and all is done. With this method you need only the vector for to sort the elements to insert. If you want I can write a small program doing this, using the code of the library.

2 2

[sort][container] Challenge for sorting experts, an improved stable sort
by Ion Gaztañaga 23 Sep '15

23 Sep '15

Hi, I'm trying to improve insertion times for flat associative containers. In range insertions one optimization is to insert the whole range in the end of the container and sort the whole vector instead of trying a loop. An additional optimization proposed in the mailing list is to have an option to create externally the internal vector type of the flat map/set, fill it and then try to move it into the flat container. That requires sorting the moved vector (and removing duplicates if needed). I could try to use std::sort/std::stable_sort but there are some problems: -> Non-portable for C++03 compilers and Boost.Move, and Boost.Container fully supports those platforms. -> Additional O(N) temporary memory for stable sorting. Usually this means a temporary N element array, although there are algorithm to use only N/2 temporary elements. With big containers, this is a lot of memory. So I started analyzing several papers and implementations to see if a custom implementation was possible, but I felt Boost.Sort could be a good place to have that implementation and the Boost community a good place to discuss design alternatives. My initial requirements: 1) Stable sort. A non-stable sort is faster and useful for unique keys containers, but stable sort can be used initially in all flat containers until the non-stable version is implemented. 2) Externally supplied auxiliary memory with optionally no auxiliary memory at all. It seems that there are newer algorithms like Grailsort (https://github.com/Mrrl/GrailSort) or WikiSort (https://github.com/BonzaiThePenguin/WikiSort) that claim O(1) memory, even no auxiliary buffer, and key comparison and data exchanges with complexity O(n*log(n)). However I don't think those implementation correctly handle the basic exception guarantee or non-trivially copyable types. Reason: I want to avoid allocating short-lived temporary memory: if it's available I want to pass the extra capacity that flat containers' internal vector holds for future insertions. 3) Customization points (without ADL, which IMHO is not customizable enough). The sort algorithm should use a SortTraits template parameter for basic operations like "move", "swap", "initialized_move". E.g: template<class T> struct sort_traits { static? void move(T &from, T &to); static? void swap(T &l, T &r); static? void uninitialized_move(T &from, void *to); static? void destroy(T &from, void *to); }; I don't know if this trait should be stateful or not (static members). I could imagine the usefulness of a stateful implementation of sort_traits that could store a reference to an allocator so that some special "construct" version is used in some operations. Or just a version that counts the number of each operation to ease debugging. In any case, a stateless version would be enough for most cases. Reason: In Boost.Container, the idea is to use boost::move + boost::adl_move_swap in the initial implementation, maybe some destructive move implementation in a second iteration if Boost.Move implements it. In any case those operations should be customizable by the user, independently from the type to be sorted. This also avoids unnecessary dependencies in Boost.Sort. -> Dependencies: the implementation should only rely on Boost.Core, Boost.Config, maybe Boost.TypeTraits and no heavy STL dependencies (optionally). Currently Boost.Sort depends on Serialization for BOOST_STATIC_WARNING, but I think this is easily solvable, maybe this static assert utility should go to the core/utility library. Reason: Sort is a low-level algorithm that should avoid pulling unneeded dependencies to other boost libraries. * * * I don't know if other Boost libraries could benefit from this new stable_sort implementation. Maybe it's too special and I should try to write it myself in Boost.Container. I would love to hear comments and suggestions from sort experts, this might be a common need that could enrich the Boost.Sort library. Best, Ion

4 9

[regression] Tests for 'develop' not showing
by Edward Diener 23 Sep '15

23 Sep '15

Trying http://www.boost.org/development/tests/develop/developer/summary.html I get: "Error extracting file: The specified zipfile was not found."

4 4

Re: [boost] Error while building boost
by Roshan 22 Sep '15

22 Sep '15

Hi, This list is specific to the Boost.Compute library. This mail is probably meant for the main Boost mailing list. Forwarding you there. P.S. I'm not sure if the attachment is being forwarded properly, please check. On Tue, Sep 22, 2015 at 12:24 PM, <valnci89(a)gmail.com> wrote: > Hi, > > > I'm trying to install boost on my machine but its not building properly. > Attached is the output generated on running ./b2 install. > > > Commands used: > > ./bootstrap.sh --prefix=/usr/include/boost > > ./b2 install > > > Machine Info: > > OS: RHEL ppc64le > > Boost version: boost_1_59_0 > > > Let me know if any other info is required. > > > Please advice me on this issue. > > > Thanks, > > Valnci > -- Warm regards Roshan

1 0

[Container] interest in a flat_unordered_map
by Treb Connell 21 Sep '15

21 Sep '15

I'm hoping to port a flat hash map that I've written to boost. Since boost has a flat_map I think it'd be good to have a flat_unordered_map as well, especially since there's an opportunity to be much more efficient. The one I would like to use is based on the hash map used in Lua, which is a mix of Coalesced and Robin Hood hashes. I don't think there's a name that describes it yet unfortunately, but I describe it near the end of this post. *Performance (primary reason for use):* It uses memory and cache very effectively and ends up being *very fast*. It's hard to benchmark real world situations, but in inserting, finding, erasing, and iterating over a dictionary it was up to six orders of magnitude faster than VS2013's unordered_map. This isn't a totally fair test because the cache efficiency really shines. *Standards compliance:* Differences from std::unordered_map are widely the same differences as flat_map listed here <http://www.boost.org/doc/libs/1_59_0/doc/html/container/non_standard_contai…>. Also bucket related methods no longer apply, so will be removed. *That said there's one major standards compliance issue that I'm struggling with:* The most optimal implementation of iterators for this container *does not have constant time traversal*. The implementation is a vector with elements scattered across it. To increment an iterator I continue to increment the internal vector iterator until I hit a new element. In practice elements should be scattered evenly, and will be close to one another, but in the worst case this is N-1. Additional memory or logic could be added to make this O(1), but I don't think that trade is worth it. In my applications of unordered_map I rarely iterate, and would not want to penalize insert, find, or erase to make iteration faster. I could make a new concept for this, pay the cost for making it truly O(1), or *since the common case is not O(N) would it be okay to consider these bidirectional iterators*? *Implementation details:* You can see Lua's implementation here <http://www.lua.org/source/5.3/ltable.c.html>. The applicable logic is in and below *luaH_newkey, *comments are useful. It's primarily a Coalesced hash table, but differs in collision behavior. When a new key collides with an old key, we check to see if the old key is in it's "*main position"*. The main position is the index that the key hashes to. If it's not in it's main position that means that it previously collided and was displaced. Since this is the new keys main position, we displace again the current key, and place ourselves there. This drastically decreases chain length, and improves the load factor that the hash map can optimally reach. Sorry about long post, can go into additional details upon request. Thanks, Treb

6 7

A compile-time-counter code snippet for boost
by Igor V. Chesnokov 21 Sep '15

21 Sep '15

2 1

[serialization] bug in static_warning.hpp
by Alain Miniussi 21 Sep '15

21 Sep '15

Hi, In static_warning.hpp we have the following code (which, if I trust its name, should trigger a *warning*): #define BOOST_SERIALIZATION_BSW(B, L) \ typedef boost::serialization::BOOST_SERIALIZATION_SS< \ sizeof( boost::serialization::static_warning_test< B, L > ) \ > BOOST_JOIN(STATIC_WARNING_LINE, L) BOOST_STATIC_ASSERT_UNUSED_ATTRIBUTE; #define BOOST_STATIC_WARNING(B) BOOST_SERIALIZATION_BSW(B, __LINE__) Now, since, since there is no BOOST_STATIC_ASSERT_UNUSED_ATTRIBUTE defined in boost (there used to be one in static_assert.hpp) this thing will generate a typedef of the form: typedef boost::serialization::BOOST_SERIALIZATION_SS< \ sizeof( boost::serialization::static_warning_test< B, L > ) \ > $STATIC_WARNING_LINE$L BOOST_STATIC_ASSERT_UNUSED_ATTRIBUTE; which is wrong. The MPI test are failing on that. Maybe BOOST_STATIC_ASSERT_UNUSED_ATTRIBUTE should be replaced with BOOST_ATTRIBUTE_UNUSED, but I am not sure what that macro is trying to achieve. Thks Alain

1 1

[locale] char conversion issue
by Alain Miniussi 21 Sep '15

21 Sep '15

Hi, My build is failing on message.cpp with: ../../../libs/locale/src/shared/message.cpp(439): error: invalid type conversion: "const wchar_t *" to "const char *" static_cast<char const *>(p), ^ detected during: [...] caused by code like: ================= template<typename CharType> struct hash_function { size_t operator()(message_key<CharType> const &msg) const { pj_winberger_hash::state_type state = pj_winberger_hash::initial_state; CharType const *p = msg.context(); if(*p != 0) { CharType const *e = p; while(*e) e++; state = pj_winberger_hash::update_state(state, static_cast<char const *>(p), static_cast<char const *>(e)); state = pj_winberger_hash::update_state(state,'\4'); } =================== Which looks like a legitimate error since that conversion does not seems t be covered by static_cast. This is on bot master and develop branch. The compiler is intel 16: [alainm@gurney build]$ icpc --version icpc (ICC) 16.0.0 20150815 Copyright (C) 1985-2015 Intel Corporation. All rights reserved. [alainm@gurney build]$ Regards Alain

2 1

[Compute] array support
by Fabian Bösch 19 Sep '15

19 Sep '15

Hi, I've been using Boost.Compute for some tests in the last couple of days. So far, it has proven very useful and I came to like it quite a bit. One thing I would add to it, though, is support for arrays when adapting your own classes for OpenCl through the Macro BOOST_COMPUTE_ADAPT_STRUCT. A simple overload would do the trick in my opinion: namespace boost { namespace compute { namespace detail { template<class Struct, class T> inline std::string adapt_struct_insert_member(T Struct::*, const char *name) { std::stringstream s; s << " " << type_name<T>() << " " << name << ";\n"; return s.str(); } template<class Struct, class T, int N> inline std::string adapt_struct_insert_member(T (Struct::*)[N], const char *name) { std::stringstream s; s << " " << type_name<T>() << " " << name << "[" << N << "]" << ";\n"; return s.str(); } } // end detail namespace } // end compute namespace } // end boost namespace Hope something along this lines can be added, thanks, Fabian

2 1

[Coroutine] Back to the caller
by Mikhail Strelnikov 18 Sep '15

18 Sep '15

Hi, I have an issue after switching from Boost.Coroutine to Boost.Coroutine2 - nested coroutine switches to its creator - not to the caller. Here is the code - http://codepad.org/WGNs0N7F There are two coroutines (1st coroutine starts, makes some progress, then spawns 2nd coroutine. But 1st coroutine knows nothing about 2nd and does not communicate with it - main thread does). With Boost.Coroutine it works as expected and outputs: g1g1g1g1g2g1g2g1g2g1g2g1g2g1g2g1 leaving coroutine 1 g2g2g2g2 leaving coroutine 2 Here you can see that 1st coroutine exits but 2nd keeps working normally. And control from coroutines is returned back to the caller (g - caller, 1 and 2 - coroutines). But with Boost.Coroutine2 it outputs: g1g1g1g1g21g1g21g1g1g21 leaving coroutine 1 assertion failed : (false) && ("pull_coroutine is complete") Here you can see that when caller (g) calls 2nd coroutine, it does not yield back to caller, but instead switches to 1st coroutine ("g21" in output).Then it terminates on assert "pull_coroutine is complete". Is it a bug of Boost.Coroutine2? If not, how can I change this code to work equally for Boost.Coroutine and Boost.Coroutine2? Thanks! P.S. What is the reason of boost::coroutines2::coroutine<void>::pull_type not having default constructor? It is still possible to have an "empty" pull_type, but it is painful process.

2 6

Interest in algorithm for arithmetic mean of integers
by Matt Calabrese 17 Sep '15

17 Sep '15

AFAICT the only function for calculating arithmetic mean in boost is in the accumulators library and it's not really appropriate for integral types. In practice, properly calculating the mean for a range (especially a range that's only an input range but not a forward range) is surprisingly tricky to do in a way that avoids overflow and provides an exact result. I have a couple of solutions, including one that works for input ranges. Is this something that people would find useful? Is there a similar algorithm already implemented in boost that I'm not aware of? The approach I've taken yields an exact result as a mixed number and should work without overflow (assuming only that the range's size is able to be represented by its difference type). I believe the implementation that works for input ranges could theoretically be adapted to work with Boost.Accumulators, though I'm admittedly not too familiar with the library. -- -Matt Calabrese

5 10

integrating NaCl support into boost
by Konstantin Ivlev 17 Sep '15

17 Sep '15

Hi boost community, some introdution: NaCl (Google NativeClient, https://developer.chrome.com/native-client) - open-source technology authored by Google Inc. providing way to run native code inside web-browser in portable and secure manner. NaCl provides posix-like environment, and supports newlib and glibc standard libraries. currently NaCl is supported by Google Chrome web-browser, and range of applications and software libraries are ported to NaCl (include zlib, quake, etc.). how about integrating NaCl support patches into the boost main-line (trunk/master), I am talking about these NaCl ports patches from Google: https://chromium.googlesource.com/external/naclports/+/master/ports/boost (I actually have a bit more correct patches that allow to compile boost 1.59 for NaCl platforms, while Google patches are still for old version 1.55). some details about patches and which boost areas are covered by patches: - boost/config - common setup for NaCl - boost/cstdint - small change to expose boost::uintptr_t/boost::intptr_t for NaCl, similarly to how it was done to other compilers - buitin.jam and gcc.jam - introduced new os-name for NaCl, in order to properly setup threading libraries (NaCl has pthread but no rt, just like BSD) - boost/system/errorcode - oddball version of strerror_r (just like cygwin), also ENOTRECOVERABLE & EOWNERDEAD errno codes are not supported by PNaCl - boost/log/light_rw_mutex - not supported on NaCl note that boost build is incomplete - certain libraries are not (yet) ported to NaCl, because of platform-specific stuff like file/network I/O : - context - coroutine - coruutine2 - log - filesystem - test - timer - wave not sure if it's OK for start, or all boost libraries should be ported together in order to process further. I would be grateful to hear suggestion about how to process with it, e.g. which actions should I take to make it really happen. I personally suppose making boost to officially support more platforms will make boost even more popular and allow more developers to use it and port their applications to other platforms. I look forward to hearing from you soon. yours sincerely, Konstantin

4 5

Windows Phone and Visual Studio 2015
by Vladimir Prus 17 Sep '15

17 Sep '15

Folks, did anybody had success building Boost for Windows Phone using Visual Studio 2015 (aka 14.0)? We have Boost.Build code to do so, but it tries to find vcvarsphoneall.bat script, and some other similarly named scripts, that I don't seem to have anywhere, despite been able to build WP app from the IDE. Has anybody solved this? Thanks, Volodya

1 1

[predef] BOOST_ARCH_BITS_* feature request
by Antony Polukhin 16 Sep '15

16 Sep '15

Hi, It looks like for low-level programming following macro could be really useful: BOOST_ARCH_BITS_64 BOOST_ARCH_BITS_32 BOOST_ARCH_BITS_16 ? Predef also missing BOOST_ARCH_ARM_64, BOOST_ARCH_PPC_64. Boost.DLL really needs those macro for detecting bit's dependent elf/macho/pe structures layout. Is it possible to add them? -- Best regards, Antony Polukhin

4 4

Copyright-less licence references
by Gennadiy Rozental 16 Sep '15

16 Sep '15

Hi, I suggest we should drop "Copyright Joe Coder 20xx" from all our files. My reasons: * git/svn history provides much better copyright attribution. Each developer has a copyright on lines authored. As it is these copyright disclaimers are very frequently wrong. * I am never clear what this line really mean. Copyright Joe Coder 2010 - does this mean Joe has copyright up to 2010, starting 2010 or only in 2010? Should one keep updating these disclaimers every January? * For libraries which are maintained by multiple developers and/or which were moved from one maintainer to another maintainer - these disclaimers either wrong or pain to maintain. * these are just a clutter with no real value IMO we should just keep licence reference and that's it: // Distributed under the Boost Software License, Version 1.0. // (See accompanying file LICENSE_1_0.txt or copy at // http://www.boost.org/LICENSE_1_0.txt) Gennadiy

12 38

Determining interest in container with efficient random access insert and erase
by Chris Clearwater 16 Sep '15

16 Sep '15

Greetings, I have written a library with the intention of submitting it to Boost.Container. My container implements O(log n) random access insert/erase and has a strong focus on performance while supporting the interfaces of the standard library sequence types. An example application would be the character buffer of a text editor. Useful links: - Source code: https://github.com/det/segmented_tree_seq - Documentation: http://det.github.io/segmented_tree_seq/ - Benchmarks: https://github.com/det/segmented_tree_seq/tree/benchmarks Any feedback is greatly appreciated.

14 28

BOOST_PP array extension proposal
by Antoine Leblanc 14 Sep '15

14 Sep '15

Hello to all of you! A few years ago, I've developped a small extension to BOOST_PP that adds a few functions to it. Namely: * ARRAY_CAT, which concatenates two BOOST_PP arrays; * ARRAY_LOWER_BOUND, which finds the index of the lower bound of an item in a given array of numerical values; * ARRAY_SORT, which sorts the given array of numerical values; * ARRAY_SORT_U, which sorts the given array and remove duplicates. I'm not sure it'd be worth adding to BOOST_PP; but if you think it might be, I'd be happy to submit a merge request. The code is rather small and can be browsed at https://github.com/nicuveo/TOOLS_PP Any suggestion or input is welcome. Thanks for your time! -- Antoine Leblanc

6 34

1.59 release notes don't mention new property_tree::json_parser
by Jonathan Wakely 14 Sep '15

14 Sep '15

The commit logs say: TL;DR: The new parser fixes long-standing bugs and has full Unicode support, but removes non-standard extensions of the old parser, which could break code: - String concatenation: the old parser concatenated adjacent string literals like C does. - Comments: the old parser supported C and C++-style comments. JSON doesn't allow comments. Removing support for comments did break something. Unfortunately there was no sign of this in the release notes, so I had to debug it the hard way (in code that swallowed the exception from the parser - gah!) and only found the commit message once I already knew what the problem was. </rant>

4 5

[type_traits] New version in master
by John Maddock 14 Sep '15

14 Sep '15

Just a quick heads up that the new version of type_traits is now in master, if there are any issues please do shout, John.

5 7

[type_traits] New version in master
by Glen Fernandes 14 Sep '15

14 Sep '15

Hi John, Any particular reason why 'is_trivially_default_constructible' was not provided as just the functionally-equivalent of 'has_trivial_default_constructor'? Glen

2 1

b2 headers failing
by Marcel Raad 13 Sep '15

13 Sep '15

Hi, when I try "b2 headers" on a fresh checkout of the develop branch, I get the following errors: C:/boost/tools/build/src/build\feature.jam:326: in validate-feature from module feature error: unknown feature "<segmented-stacks>" C:/boost/tools/build/src/build\feature.jam:360: in expand-subfeatures-aux from module feature C:/boost/tools/build/src/build\feature.jam:425: in feature.expand-subfeatures from module feature C:/boost/tools/build/src/build\property.jam:508: in property.translate from module property C:/boost/tools/build/src/build\property-set.jam:432: in property-set.create-from-user-input from module property-set C:/boost/tools/build/src/build\property-set.jam:484: in property-set.refine-from-user-input from module property-set C:/boost/tools/build/src/build\project.jam:700: in class(a)project-attributes.set from module object(project-attributes)@369 C:/boost/tools/build/src/build\project.jam:1099: in project from module project-rules libs\coroutine2\build\Jamfile.v2:26: in modules.load from module Jamfile<C:\boost\libs\coroutine2\build> C:/boost/tools/build/src/build\project.jam:325: in load-jamfile from module project C:/boost/tools/build/src/build\project.jam:64: in load from module project C:/boost/tools/build/src/build\project.jam:89: in load-used-projects from module project C:/boost/tools/build/src/build\project.jam:75: in load from module project C:/boost/tools/build/src/build\project.jam:145: in project.find from module project C:/boost/tools/build/src\build-system.jam:535: in load from module build-system C:\boost\tools\build\src/kernel\modules.jam:295: in import from module modules C:\boost\tools\build\src/kernel/bootstrap.jam:139: in boost-build from module C:\boost\boost-build.jam:17: in module scope from module Does anyone know what's wrong here? Thanks, Marcel -- View this message in context: http://boost.2283326.n4.nabble.com/b2-headers-failing-tp4680039.html Sent from the Boost - Dev mailing list archive at Nabble.com.

1 1

[AFIO] Formal review
by Jeremy Maitin-Shepard 12 Sep '15

12 Sep '15

> 1. Should Boost.AFIO be accepted into Boost? Please state all conditions for > acceptance explicity. In its current state, Boost.AFIO should NOT be accepted into Boost. However, I am confident that Niall will be able to deliver a future version of AFIO that should be accepted into Boost after another review. There is a great need for more powerful and efficient file handling functionality in C++ than is provided by iostreams and Boost.Filesystem/Filesystem TS. I appreciate the enormous complexity of trying to define a multi-platform filesystem interface, and it is clear that Niall has done a ton of very valuable research on this topic. > 2. What is your evaluation of the design? A key strength of the design is that it provides a common interface for asynchronous operations regardless of whether they are internally implemented using Windows IOCP support, async IO on FreeBSD, or regular POSIX operations via a thread pool. Another key strength is that it exposes handle-based (i.e. *at), rather than path-based APIs where possible in order to minimize race conditions, which tend to be difficult or impossible to avoid completely with file system operations. I do have a number of concerns about several aspects of the design, however: Batch API: - It is not clear what, if any, purpose the batch API serves. The significant added complexity of using it would have to be justified by a significant performance advantage, but it is not at all clear that there is even any performance advantage at all. - I suggest removing it unless there is a strong argument otherwise. File handle API: - The file handle abstraction in AFIO is very heavy weight, involving a shared_ptr to a structure containing a whole bunch of fields in addition to the native file handle, including a mutex, numerous flags, the path used to open it, a pointer to a handle to the parent directory, a chrono time_point specifying the time the file was opened, the total number of bytes read, written, and written since last fsync using this file handle. - Because file handles are at the core of AFIO, it is critical that users precisely understand what this abstraction involves, and specifically how it differs from a native file handle. - I'd be much more comfortable with a much leaner abstraction, like a unique_handle type that just contains the bare native handle, and uses unique ownership semantics. The fat handles impose both computational/memory overhead as well as mental overhead on the programmer. I understand these extra fields are probably necessary to provide various functionality, particularly emulation of behavior provided by other operating systems, but it would be nicer to be able to opt-in to such functionality and only pay for it when needed. - At the very least, if these fat file handles are kept, a very strong argument needs to be given as a rationale. (Perhaps you have found the overhead to be negligible relative to the cost of the native file handle.) - It should be possible to construct an AFIO handle from a native file descriptor. - On POSIX, AFIO should support supplying platform-specific open flags, like O_NOATIME. - I'd much prefer native_handle() to return the actual appropriate native handle type for the platform, e.g. int on POSIX, rather than a void *. I'm guessing this is done in order to support alternative dispatchers, that aren't necessarily based on OS files at all, in the future, but perhaps a better way of doing this that doesn't require casting the void* to an int, can be found. Future-based API: - I agree with Thomas Heller regarding the Future-based API: - The implicit future.then built into the API should be eliminated. Instead, API functions should take a file handle directly. - future<T> should not implicitly store a file handle. The API functions that open a file can return a future to a file_handle. API functions that don't open a new file should just return a future to the actual result. Inconsistency in how operations are defined: - Some operations are methods of the dispatcher, some are methods of the file handle, and others are free functions. - I suggest that all file system operations be free functions, and take a dispatcher as an argument. Thread-local current dispatcher: - Some operations involve an explicitly specified dispatcher, others seem to obtain it from the file handle, and others default to a thread-local dispatcher that has been set. - Given that it is extremely likely for user code to execute from multiple threads given the nature of AFIO, relying on a thread-local current dispatcher seems very error prone. - I suggest that the thread-local current dispatcher be eliminated, and that the dispatcher always be specified explicitly to any API call that requires one. Directory handle cache: - A cache of open handles to directories is kept by AFIO by default. This is particularly problematic because (as is documented) it makes reading directory entries thread-unsafe by default. If this is to be kept, a very strong rationale needs to be given, and the behavior must be changed somehow to ensure that directory reading is reliable by default. Enumerate API: - The future-based API of async_enumerate seems to be unnecessarily complicated, due to the need to specify maxitems and deal with making repeated calls, and all of the copying and memory allocation required to return a std::vector of directory_entry. I suggest instead something like passing in a std::function<bool (expected<directory_entry> const &next)> callback (possibly replacing expected by the new name for your monad type). An empty next value means end of directory has been reached. Returning true means continue listing the directory, returning false means stop listing the directory. Miscellaneous comments: - Operations including rmdir, rmfile, symlink, rmsymlink (as well as async variants) that normally would not necessarily even operate on file handles, actually return a handle_ptr. Perhaps if on some platforms a handle has to be opened, then there could be a way for the user to specify that a handle is desired. Otherwise, it would make sense to just return void or std::future<void> equivalent for async variants. - The documentation notes that on MS Windows, DOS short names are not supported. I don't have much familiarity with Windows, but if programs generally accept DOS short names when a filename is required, then AFIO should probably support these names as well. - The documentation notes: "Don't do directory enumerations from an x86 binary on a x64 Windows system. This is due to a bug in Microsoft's WOW64 syscall translation layer which Microsoft have decided is wontfix. " Given that a major purpose of AFIO is to provide a portable abstraction that works around OS limitations, AFIO needs to support directory enumeration even in this case (e.g. by detecting WOW64 and using a synchronous call via a threadpool in that case). - It is noted that to do an asynchronous stat you have to use enumerate with an appropriate glob specified, but constructing such a glob may be non-trivial if the path contains characters that are interpreted specially by the glob syntax, and impossible to do in a race-free manner. - As a general matter, it is important to provide leanest possible API that offers the most flexibility to users, in order to avoid the case that users choose not to use the library despite it offering a lot of functionality that is useful to them, because of excessive overhead or insufficiently powerful interfaces. I often forgo use of Boost Filesystem and C++ iostreams for this reason. 3. What is your evaluation of the implementation? - I understand that Niall already intends to rewrite much of the implementation, making much of the current implementation irrelevant. - As has been noted by other reviewers, there are a bunch of #if 0 blocks, many undocumented. Some seem to contain work in progress, which might better be placed in a separate branch. Some contain debugging code, in which case it might be better to replace #if 0 with #ifdef BOOST_AFIO_DEBUG_XXX where XXX specifies the particular feature being debugged. That way it is self-documenting. Some seem to contain alternate implementations. Ideally these would also be guarded by a descriptive macro, and a unit test case be defined that tests it as well to make sure it is still meaningful. Otherwise #if 0 code tends to bitrot, which admittedly is not such a great problem if it is just for debugging anyway, but I'd say it is less than optimal. - The implementation might be better split up into multiple independent files. There are various independent facilities, like secded_ecc, that could be placed in a separate file. - Although this tends to be a problem with most Boost libraries, it would be nice if the compile times could be reduced, particularly when not in header-only mode. Some libraries like Boost Spirit have an interface inherently based on template metaprogramming, such that long compile times are pretty much unavoidable, but the Boost AFIO interface seems to be mostly non-template based, which suggests that it may be possible to get pretty good compile times. > 4. What is your evaluation of the documentation? - The extensive documentation about race guarantees is extremely useful. - I appreciate the in-depth examples. - Much more design rationale is needed. - The term "filing system" is used in place of the more common "file system", leading me to wonder if there is a difference in meaning. - Every instance where there is a platform-specific #ifdef in an example should be evaluated, so that you can figure out the appropriate platform-independent abstraction that could be added to AFIO in order to move that #ifdef into the library and out of user code. - There is an attempt to document differences in behavior on different platforms, but this is not done sufficiently. For example, it is stated that async_write requires that the destination region does not go off the end of the file, but on POSIX pwrite supports this just fine as a way to extend the file. I assume that this restriction applies to Windows only. - The semantics of the Batch API are not precisely documented, nor is any rationale given for it. For instance, I understand that the operations themselves cannot happen atomically, since that is not supported by operating systems, though this is not clearly stated. It is stated: "Once a batch of input ops has been verified at the point of entry as not errored, you are guaranteed that the batch is atomically scheduled as a whole, unless a failure to allocate memory occurs." Does this means that if the *_req object involves futures, it waits for all of them to be ready before launching any of the operations in the batch? Is that the purpose of the Batch API, to do a wait_all on all of the relevant futures, then to launch each operation? This issue goes away though if the Batch API is eliminated, as seems to make sense. - It would be useful to document for each operation which underlying system calls it invokes on each platform. - Many operations other than open (e.g. rmfile) take file_flags, but it is not specified which flags are supported. - References to historical versions of AFIO (prior to the review) should be removed from the main parts of the documentation, since they only distract from the useful information. This information could be kept in a different section at the end for the extra curious. - Formatting of the "description" in the Boost Quickbook format function documentation has some problems: the lack of line breaks between the general description, other notes, and the common note about the use of NT kernel paths make it difficult to read. > 5. What is your evaluation of the potential usefulness of the library? The library is potentially extremely useful. C++ and Boost iostreams and Boost/TS Filesystem provide only very limited functionality. The C library libuv is a close competitor but seems to offer less functionality and a less convenient API. For achieving similar functionality, the status quo in C++ is to rely on platform-specific C APIs that are much more cumbersome to use. > 6. Did you try to use the library? With what compiler? Did you have any problems? I tried some very simple usage of the library with GCC 5.2.0 on Linux. There were a few warnings (variable set but not used) with -Wall that would be best eliminated. - The error messages are not ideal: for instance, in the case that there was an error opening a file, this is the result: Dynamic exception type: boost::system::system_error std::exception::what: File '/home/jbms/tmp/afio-test/test.txt' not found [Host OS Error: No such file or directory (2) in '/home/jbms/tmp/boost.afio/include/boost/afio/v2/detail/impl/afio.ipp': async_io_handle_posix:805]: No such file or directory. Op was scheduled at: 1. 0x42fb4f: ./test (+0x2fb4f) : No such file or directory Some of this is only useful when debugging AFIO, some only useful when debugging the application, and there is a lot of redundancy, for instance the actual error "No such file or directory" is shown in 3 places. Ideally there would be a way to get a simple message along the lines of "Error opening file '/home/jbms/tmp/afio-test/test.txt': No such file or directory" that could be shown directly to the user. I tried to #define BOOST_AFIO_EXCEPTION_DISABLESOURCEINFO to see if that would make the error message better, but instead that seemed to trigger a bug: Dynamic exception type: std::logic_error std::exception::what: basic_string::_S_construct null not valid - A separate issue is that attempting to read a range that is not present in a file, something that the library should handle elegantly, leads to the program aborting immediately with an error message, rather than allowing the error to be handled: FATAL EXCEPTION: Failed to read all buffers 1. 0x40f0f4: ./test (+0xf0f4) terminate called after throwing an instance of 'std::runtime_error' what(): Failed to read all buffers zsh: abort (core dumped) ./test > 7. How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? I gave the library a fairly in-depth study, spending at least 8 hours in total. I looked at the documentation fairly thoroughly, looked through parts of the implementation, and tried running a couple small programs that use the library. > 8. Are you knowledgeable about the problem domain? I have a fair amount of experience with asynchronous programming in C++, and I have pretty extensive knowledge of the file system APIs on Linux. As a final note, I'd like to thank Niall for all of the work he has done to get the library this far. A powerful, elegant, cross-platform interface for file system operations is very much needed in C++, I really do want to see (a future version of) this library in Boost and use it myself.

11 32

Boost.Fiber mini-review September 4-13
by Nat Goodspeed 11 Sep '15

11 Sep '15

Hi all, The mini-review of Boost.Fiber by Oliver Kowalke begins today, Friday September 4th, and closes Sunday September 13th. It was reviewed in January 2014; the verdict at that time was "not in its present form." Since then Oliver has substantially improved documentation, performance, library customization and the underlying implementation, and is bringing the library back for mini-review. The substance of the library API remains the same, which is why a mini-review is appropriate. The Fiber library now requires a C++14-conforming compiler. I will monitor reviews and discussion on both the boost-users@ list and the boost@ developers' list. Please include at least "fiber" and "review" in your mail subject, e.g. by replying to this message. (Please reply to only ONE list, however.) Thank you for your interest and your feedback! ----------------------------------------------------- About the library: Boost.Fiber provides a framework for micro-/userland-threads (fibers) scheduled cooperatively. The API contains classes and functions to manage and synchronize fibers similar to Boost.Thread. Each fiber has its own stack. A fiber can save the current execution state, including all registers and CPU flags, the instruction pointer, and the stack pointer and later restore this state. The idea is to have multiple execution paths running on a single thread using a sort of cooperative scheduling (versus threads, which are preemptively scheduled). The running fiber decides explicitly when it should yield to allow another fiber to run (context switching). Boost.Fiber internally uses execution_context from Boost.Context; the classes in this library manage, schedule and, when needed, synchronize those contexts. A context switch between threads usually costs thousands of CPU cycles on x86, compared to a fiber switch with a few hundred cycles. A fiber can only run on a single thread at any point in time. docs: http://olk.github.io/libs/fiber/doc/html/index.html git: https://github.com/olk/boost-fiber --------------------------------------------------- Please always state in your review whether you think the library should be accepted as a Boost library! Additionally please consider giving feedback on the following general topics: - What is your evaluation of the design? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - What is your evaluation of the potential usefulness of the library? - Did you try to use the library? With what compiler? Did you have any problems? - How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? - Are you knowledgeable about the problem domain? Nat Goodspeed Boost.Fiber Review Manager ________________________________

11 108

[fiber] on schedulers and wakeups
by Giovanni Deretta 11 Sep '15

11 Sep '15

Hi Oliver, I'm looking at the boost.fiber scheduling customization options. I have a few comments. My first concern is that scheduler is a global (per thread) property. This makes sense, but it limits its usability in libraries, unless the library completely owns a thread. It would be nice if schedulers where schedulable entities themselves, so that they could be nested (more at the end). Also the description of the scheduler interface does not specify any thread safety requirements. I assume that at least awakened must be thread safe as the scheduling might be caused by a signal coming from another thread. Any requirements should be specified properly. This leads to two additional points. First of all, there should be a way to retrieve the scheduler associated with a fiber: I haven't looked at the source, but the association must exist internally, otherwise cross thread scheduling wouldn't work. Second, there does not seem to be a way to allow signaled fibers to run in the context of the signaling thread. This seems an important optimization.I understand this is an explicit decision as currently it is not possible to portably migrate fibers, but the option should be left to the user if he knows it is safe in their setup. Possibly require 'awakened(fiber*x)' to call x->get_scheduler()->awakened(x) if it does not support running the fiber. My preference is to add a queryable boolean flag to each schedulable entity that states whether it is allowed to move from its scheduler (this makes a difference when you have multiple nested schedulers). Among other things this would also prevent work stealing. The flag would by default be set to prevent migration of course. Now, what do nested schedulers give you? In addition to composability, you can have the equivalent of an asio strand without explicit mutual exclusion. Let say you have a bunch of fibers that all access the same resource; you do not care where they run, as long as they never run concurrently. By binding all of them to the same scheduler, the guarantee is implicit. It should be possible to implement nested schedulers by having each fiber set the current scheduler pointer if it differs and store the previous one. On a scheduling event, if the current scheduler runs out of runnables, the signal/yield code would restore the previous scheduler and try again. Of course handling priorities and non strict fifo scheduling might be more complex. Note that the multi scheduler logic need to be implemented by Boost.Fiber itself. Finally, it might be possible (but I haven't tested this) to make fibers migrable on platforms where it normally isn't safe by allocating an actual thread for each one. The thread would be stopped as soon as it has been created, but a thread control block plush TLS entries would have been allocated. The existing context switch would need to be augmented with the ability to swap the thread context pointer. HTH, -- gpd

4 23

Critical. Help required. Boost.DLL Jamfile breaks testing with multiple toolsets
by Antony Polukhin 10 Sep '15

10 Sep '15

Hi, There's a big problem with Boost.DLL's Jamfile which I do not know how to fix. Introduction Tests of Boost.DLL create multiple *.so files and install them to a specified TEST_DIR path. Tests consume that TEST_DIR path and search for *.so in there: path-constant TEST_DIR : $(BOOST_ROOT)/bin.v2/libs/dll/test ; project : source-location . : requirements ; { # our test lib for shared library tests lib test_library : test_library.cpp : <link>shared ; lib getting_started_library : ../example/getting_started_library.cpp : <link>shared ; install install-bin : test_library getting_started_library : <location>$(TEST_DIR) ; test-suite boostdll : [ run shared_library_load_test.cpp : $(TEST_DIR) : : <dependency>install-bin ] [ run shared_library_search_symbol_test.cpp : $(TEST_DIR) : : $(RDYNAMIC) <dependency>install-bin ] ; } The Problem If multiple toolsets specified, then `install-bin` target gets broken: cd libs/dll/test ../../../b2 toolset=gcc,clang error: Tried to build the target twice, with property sets having error: these incompatible properties: error: error: - <cxxflags>-Wall -Wextra -pedantic -Wno-long-long <library>object(file-target)@3829 <library>object(file-target)@3862 <toolset-gcc:version>4.8 <toolset>gcc <xdll-path>/home/antoshkka/boost_maintain/boost/bin.v2/libs/filesystem/build/gcc-4.8/debug/threading-multi <xdll-path>/home/antoshkka/boost_maintain/boost/bin.v2/libs/system/build/gcc-4.8/debug/threading-multi error: - <library>object(file-target)@7264 <library>object(file-target)@7296 <toolset-clang:platform>linux <toolset-clang:version>3.4 <toolset>clang <xdll-path>/home/antoshkka/boost_maintain/boost/bin.v2/libs/filesystem/build/clang-linux-3.4/debug/threading-multi <xdll-path>/home/antoshkka/boost_maintain/boost/bin.v2/libs/system/build/clang-linux-3.4/debug/threading-multi Correct fix would be to embed into TEST_DIR the names of toolset and all other configuration flags. path-constant TEST_DIR : $(BOOST_ROOT)/bin.v2/libs/dll/test/$(FLAGS)/$(TOOLSET) ; The Question How to get the $(FLAGS) and $(TOOLSET) variables? If that requires writing rules or implies some other Boost.Build magic I'd really appreciate a pull request: any nontrivial modification to Jamfile takes months to apply and test because of my poor knowledge of Boost.Build. Jamfile: https://github.com/boostorg/dll/blob/develop/test/Jamfile.v2 Boost.DLL: https://github.com/boostorg/dll This issue is critical, because it breaks regression testing (see "[boost] [android][regression] bjam failed") -- Best regards, Antony Polukhin

5 9

Find All Paths
by Tom Skora 10 Sep '15

10 Sep '15

I have a list of vertices and using unidirectional edges, create multiple start and end paths starting from a start vertex. Ex. Vertices= 1,2,3,4,5, 6 Edges = (1,2), (2,3), (2,4), (2,5), and (5, 6) I would like to put in vertex 1 and have the following lists returned: 1,2,3 and 1,2, 4 and 1,2, 5, 6 What function can I use to return those lists Thanks Sent from my iPhone

1 0

[git] Stalled submodule updates?
by Rene Rivera 09 Sep '15

09 Sep '15

I was investigating why testing is currently broken.. And narrowed it down to the tools/build subproject on develop not being up to date with the current build submodule commit. Anyone know what has gone awry with the auto-updates of the super project? -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net -- rrivera/acm.org (msn) - grafikrobot/aim,yahoo,skype,efnet,gmail

2 2

[type_traits] Time to merge Version 2 to the master branch?
by Ion Gaztañaga 09 Sep '15

09 Sep '15

Hi, Once Boost 1.59 is out, I'd like to suggest merging TypeTraits V2 to the master branch. It's a great job that will reduce boost library dependencies. Any chance this can happen soon? Best, Ion

4 5

[container] Implemented Polymorphic Memory Resources
by Ion Gaztañaga 09 Sep '15

09 Sep '15

Hi to all, In case anyone is interested, I just committed to the develop branch the implementation of the proposal "N3916 Polymorphic Memory Resources - r2" that was included in the TS "C++ Extensions for Library Fundamentals". The library continues to support C++03 compilers. It basically introduces in namespace boost::container::pmr and the path boost/container/pmr/: - memory_resource - synchronized_pool_resource - unsynchronized_pool_resource - monotonic_buffer_resource - polymorphic_allocator - resource_adaptor - new_delete_resource / null_memory_resource / get_default_resource / set_default_resource - Aliases for all containers, using the polymorphic_allocator. As default resource, new_delete_resource and null_memory_resource are required to be globals, they are implemented in the separately compiled boost.container library that was used to implement the DLMalloc-based extended allocator. It seems that many users dislike building Boost libraries, but I felt this was the correct way to implement it. We could change or make it optionally header-only if there is demand. To avoid dependencies to some users, I made sure that memory_resource and resource_adaptor, which don't depend on the global default memory resource, can be used without linking the library. Some logic was refactored from scoped_allocator_adaptor to avoid repeating the complicated template and preprocessor machinery in the polymorphic_allocator. I hope this does not cause any problem to scoped allocator users. Any suggestion or bug report is welcome. Best, Ion

5 8

Compiling with Clang 3.7.0 from windows
by Paul A. Bristow 09 Sep '15

09 Sep '15

I've downloaded the shiny new Clang 3.7 and added this to my user-config. # 64-bit version using clang # from http://llvm.org/releases/download.html : # version 3.7.0 : # Clang compiler .exe location #"C:/LLVM/bin/clang++.exe" # OK #"C:\\Program Files (x86)\\LLVM\\bin\\clang++.exe" # OK "C:\\Program Files\\LLVM\\bin\\clang++.exe" # : # options ; If I compile a simple hello world (no Boost library calls) program using the defaults (jam (using up-to-date Boost develop branch) it fails at the link complaining c:\mingw\bin\ld.exe: unrecognised emulation mode: i386pep Supported emulations: i386pe which seems an odd message??? I:\modular-boost\libs\quickdox\example>b2 toolset=clang-3.7.0 Performing configuration checks - 32-bit : no (cached) - 64-bit : yes (cached) - arm : no (cached) - mips1 : no (cached) - power : no (cached) - sparc : no (cached) - x86 : yes (cached) - symlinks supported : yes (cached) ...found 22 targets... ...updating 4 targets... clang-linux.compile.c++.without-pth ..\..\..\bin.v2\libs\quickdox\example\quick_auto_dox_index.test\clang-linux-3.7.0\debug\quick_auto_d ox_index.obj clang version 3.7.0 (tags/RELEASE_370/final) Target: x86_64-w64-windows-gnu Thread model: posix "C:\\Program Files\\LLVM\\bin\\clang++.exe" -cc1 -triple x86_64-w64-windows-gnu -emit-obj -mrelax-all -disable-free -main-file-name quick_auto_dox_index.cpp -mrelocation-model pic -pic-level 2 -mthread-model posix -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -target-cpu x86-64 -momit-leaf-frame-pointer -v -g -dwarf-column-info -coverage-file "I:\\modular-boost\\libs\\quickdox\\example\\..\\..\\..\\bin.v2\\libs\\quickdox\\example\\quick_auto _dox_index.test\\clang-linux-3.7.0\\debug\\quick_auto_dox_index.obj" -resource-dir "C:\\Program Files\\LLVM\\bin\\..\\lib\\clang\\3.7.0" -D BOOST_ALL_NO_LIB=1 -I "..\\..\\.." -I "..\\include" -internal-isystem "c:\\mingw\\mingw32\\include\\c++" -internal-isystem "c:\\mingw\\mingw32\\include\\c++\\mingw32" -internal-isystem "c:\\mingw\\mingw32\\include\\c++\\backward" -internal-isystem "c:\\mingw\\mingw32\\include\\c++\\4.8.1" -internal-isystem "c:\\mingw\\mingw32\\include\\c++\\4.8.1\\mingw32" -internal-isystem "c:\\mingw\\mingw32\\include\\c++\\4.8.1\\backward" -internal-isystem "c:\\mingw\\include\\c++\\4.8.1" -internal-isystem "c:\\mingw\\include\\c++\\4.8.1\\mingw32" -internal-isystem "c:\\mingw\\include\\c++\\4.8.1\\backward" -internal-isystem "c:\\mingw\\lib\\gcc\\mingw32\\4.8.1\\include\\c++" -internal-isystem "c:\\mingw\\lib\\gcc\\mingw32\\4.8.1\\include\\c++\\mingw32" -internal-isystem "c:\\mingw\\lib\\gcc\\mingw32\\4.8.1\\include\\c++\\backward" -internal-isystem "C:\\Program Files\\LLVM\\bin\\..\\lib\\clang\\3.7.0\\include" -internal-isystem "c:\\mingw\\lib\\gcc\\mingw32\\4.8.1\\include" -internal-isystem "c:\\mingw\\mingw32/sys-root/mingw/include" -internal-isystem "c:\\mingw\\lib\\gcc\\mingw32\\4.8.1\\include-fixed" -internal-isystem "c:\\mingw\\mingw32\\include" -internal-isystem "c:\\mingw\\include" -O0 -Wall -fdeprecated-macro -fdebug-compilation-dir "I:\\modular-boost\\libs\\quickdox\\example" -ferror-limit 19 -fmessage-length 0 -mstackrealign -fno-use-cxa-atexit -fno-inline -fobjc-runtime=gcc -fcxx-exceptions -fexceptions -fdiagnostics-show-option -o "..\\..\\..\\bin.v2\\libs\\quickdox\\example\\quick_auto_dox_index.test\\clang-linux-3.7.0\\debug\\q uick_auto_dox_index.obj" -x c++ quick_auto_dox_index.cpp clang -cc1 version 3.7.0 based upon LLVM 3.7.0 default target x86_64-w64-windows-gnu ignoring nonexistent directory "c:\mingw\mingw32\include\c++" ignoring nonexistent directory "c:\mingw\mingw32\include\c++\mingw32" ignoring nonexistent directory "c:\mingw\mingw32\include\c++\backward" ignoring nonexistent directory "c:\mingw\mingw32\include\c++\4.8.1" ignoring nonexistent directory "c:\mingw\mingw32\include\c++\4.8.1\mingw32" ignoring nonexistent directory "c:\mingw\mingw32\include\c++\4.8.1\backward" ignoring nonexistent directory "c:\mingw\include\c++\4.8.1" ignoring nonexistent directory "c:\mingw\include\c++\4.8.1\mingw32" ignoring nonexistent directory "c:\mingw\include\c++\4.8.1\backward" ignoring nonexistent directory "c:\mingw\mingw32/sys-root/mingw/include" ignoring nonexistent directory "c:\mingw\mingw32\include" #include "..." search starts here: #include <...> search starts here: ..\..\.. ..\include c:\mingw\lib\gcc\mingw32\4.8.1\include\c++ c:\mingw\lib\gcc\mingw32\4.8.1\include\c++\mingw32 c:\mingw\lib\gcc\mingw32\4.8.1\include\c++\backward C:\Program Files\LLVM\bin\..\lib\clang\3.7.0\include c:\mingw\lib\gcc\mingw32\4.8.1\include c:\mingw\lib\gcc\mingw32\4.8.1\include-fixed c:\mingw\include End of search list. clang-linux.link ..\..\..\bin.v2\libs\quickdox\example\quick_auto_dox_index.test\clang-linux-3.7.0\debug\quick_auto_d ox_index.exe c:\mingw\bin\ld.exe: unrecognised emulation mode: i386pep Supported emulations: i386pe clang++.exe: error: linker command failed with exit code 1 (use -v to see invocation) "C:\Program Files\LLVM\bin\clang++.exe" -o "..\..\..\bin.v2\libs\quickdox\example\quick_auto_dox_index.test\clang-linux-3.7.0\debug\quick_auto_ dox_index.exe" -Wl,--start-group "..\..\..\bin.v2\libs\quickdox\example\quick_auto_dox_index.test\clang-linux-3.7.0\debug\quick_auto_ dox_index.obj" -Wl,-Bstatic -Wl,-Bdynamic -Wl,--end-group -g -m64 ...failed clang-linux.link ..\..\..\bin.v2\libs\quickdox\example\quick_auto_dox_index.test\clang-linux-3.7.0\debug\quick_auto_d ox_index.exe... ...skipped <p..\..\..\bin.v2\libs\quickdox\example\quick_auto_dox_index.test\clang-linux-3.7.0\debug>quick_auto _dox_index.run for lack of <p..\..\..\bin.v2\libs\quickdox\example\quick_auto_dox_index.test\clang-linux-3.7.0\debug>quick_auto _dox_index.exe... ...failed updating 1 target... ...skipped 2 targets... ...updated 1 target... If I specify address-model=32, then it runs OK - but still says "64-bit : yes (cached)" which isn't what I would expect? I:\modular-boost\libs\quickdox\example>b2 -a toolset=clang-3.7.0 address-model=32 Performing configuration checks - 32-bit : no (cached) - 64-bit : yes (cached) <<<<<<<<<<<<<<<<<<< ??????????????????? <snip> [Also example>b2 -a toolset=clang-3.7.0 address-model=64 fails to link as with no address-model specified (so default is 64 bit?)]. Suggestions? (Have I got the wrong version of mingw? I have others from ming64 - how do I specify to use those?) Thanks Paul --- Paul A. Bristow Prizet Farmhouse Kendal UK LA8 8AB +44 (0) 1539 561830

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Re: [boost] Common future base class (was Re: Boost.Fibermini-review September 4-13)
by Nat Goodspeed 07 Sep '15

07 Sep '15

On Sun, Sep 6, 2015 at 2:07 PM, Hartmut Kaiser <hartmut.kaiser(a)gmail.com> wrote: >> I've always found when_any much more interesting than when_all. Is it as >> trivial to implement with await as when_all? > Nod, I agree. However, I have not found a clever way to do that yet. On Mon, Sep 7, 2015 at 9:39 AM, Anthony Williams <anthony.ajw(a)gmail.com> wrote: > On 07/09/15 14:36, Agustín K-ballo Bergé wrote: >> On 9/7/2015 4:32 AM, Anthony Williams wrote: >>> On 03/09/15 16:47, Agustín K-ballo Bergé wrote: >>>> calling `set_value` on the same instance from different >>>> threads concurrently is expected to work, as in only one (unspecified) >>>> of them will actually make the shared state ready while all the others >>>> would throw `promise_already_satisfied`? >>> Yes, that was the intent. I've got an example that does exactly that in >>> chapter 8 of my book. >> Could you describe briefly what this example does? Is it just workers >> racing (in the good sense) to satisfy the promise? Or does serialization >> of set_xxx calls matter? > It's just workers racing to satisfy the promise. The first one to do so > sets the value, the rest get an exception. Seems like that could be the basis for a nice when_any?

2 1

Re: [boost] [Boost-users] Boost.Fiber mini-review September 4-13
by Vicente J. Botet Escriba 07 Sep '15

07 Sep '15

Le 06/09/15 02:21, Vicente J. Botet Escriba a écrit : > Le 05/09/15 16:27, Nat Goodspeed a écrit : >> On Fri, Sep 4, 2015 at 5:08 PM, Vicente J. Botet Escriba >> <vicente.botet(a)wanadoo.fr> wrote: >> >>> Le 04/09/15 20:37, Nat Goodspeed a écrit : >>>> On Fri, Sep 4, 2015 at 2:07 PM, Vicente J. Botet Escriba >>>> <vicente.botet(a)wanadoo.fr> wrote: >>>>> Please could you recall us what "not in the present form" meant as a >>>>> result >>>>> of the review and what has been done to overcome these issues? >>>> http://lists.boost.org/boost-announce/2014/01/0393.php >>>> >>>> I have not yet tried to address those point by point. >>> I don't understand then why are we doing the mini review now, before >>> you >>> check that any point has at least tried to be addressed. >> Sorry. How about these points: >> >> Performance: Oliver has not only worked to improve performance, he has >> included and documented performance tests you can run on your own >> hardware. > Great, I will check. > See below. >> Documentation: The documentation now contains several new sections >> explaining how to use the library for interesting/common use cases. >> New examples are presented and documented. > See below. >> >> API: The API has been aligned more closely with std::thread. C++14 is >> not only supported but required. Move-only callables are supported. >> Variadic parameters are supported. std::chrono is more generically >> supported. Channels now support value_pop(). fiber_group has been >> dropped. Migrating fibers between threads has been dropped. > See below. >> That said, of course, it is up to each reviewer to state for him- or >> herself whether s/he believes that the Fiber library should become >> part of Boost. In particular, regardless of what Oliver or I might >> synopsize, it is up to each previous reviewer to decide whether his >> January 2014 objections have been addressed. > To be clear, I believe that by respect to the reviewers you should > take the review summary you wrote and add a comment for each point. > > Best, > Vicente Hi again, In addition to my last request and in order to be able to write a review, I would like to know what exactly has been changed since the first review, what was expected after the review summary and what was removed, changed or added and what was the rationale. Best, Vicente

2 1

[android] New compilers: gcc-5.2 and clang-3.7
by Dmitry Moskalchuk 03 Sep '15

03 Sep '15

Hi all, We've added new compilers into CrystaX NDK recently: gcc-5.2 and clang-3.7 (old gcc-4.9 and clang-3.6 still there too). Testing results should appear on Boost regression page in a few days. Both compilers have fully passed our automatic tests, but you know, there still could be bugs, especially in such complicate projects. We're asking all maintainers of the Boost libraries look on that results and report us bugs (if any) to https://tracker.crystax.net/projects/ndk. The most important for us is catching regressions caused by new compilers compared to theirs previous versions. In case of such bugs, please don't add workarounds into Boost code; better report and let us fix them in CrystaX NDK. Thank you. -- Dmitry Moskalchuk

1 0

[Boost.AFIO] Formal Review
by Joel FALCOU 02 Sep '15

02 Sep '15

> 1. Should Boost.AFIO be accepted into Boost? The topic of asynchronous file operation is very very important and quite critical in our days. Boost needs such a library but I fear *current* AFO is not there yet. I vote NO for its inclusion in Boost in its current form. > 2. What is your evaluation of the design? I think the intent are goods but there's some icky parts. The use of future and other asynchronous element in the API cudl be made more clear and easy. Thomas Heller made a compelling lsit of gotcha that shoudl be followed. Currently i had to fight against my habit of writing future absed code to get the stuff working. > 3. What is your evaluation of the implementation? Next to small scale issues like mammoth headers and liberal use of allocation in the implementation of some functions, I think the main culprit is to simplify the implementation by splitting the ABI stable part into another component. Also, the way asynchronous cmponents are used internally hould be aligned with the required fix on the public API. > 4. What is your evaluation of the documentation? The documentation is hard to follow and some 'simple example' are clearly not that simple. This should be the second major point of improvement. > 5. What is your evaluation of the potential usefulness of the library? THis kind of library is very useful and as I said, we need one with proper design and implementation. > 6. Did you try to use the library? Played around with the examle and the doc. > 7. How much effort did you put into your evaluation? Roughly 10-12 hours > 8. Are you knowledgeable about the problem domain? Not with async file I/O but I have a fair amount of experience in asynchronous computation and parallel programming in general. As a concluding note, I *really* want Niall to keep going on making AFIO the reference async file I/O library. Just take the needed time to reflect on the afformentionned PAI and implementation issues and remember that there is no rush to get there.

3 3

boost::python::make_setter(&X::y) no longer compiles
by Jonathan Wakely 02 Sep '15

02 Sep '15

This compiled with 1,58, it doesn't with 1.59: #include <boost/python.hpp> struct X { int y; }; int main() { boost::python::make_setter(&X::y); } Is this intentional? Is it documented somewhere? The examples in the docs still seem to use this form.

1 1

[atomic] Generalized read-modify-write operation
by Andrey Semashev 02 Sep '15

02 Sep '15

Hi, I was wondering is there would be interest in a generalized read-modify-write operation in Boost.Atomic. The idea is to have a atomic<T>::read_modify_write method that would take a function that would perform the modify on the atomic value. The interface could be roughly this: template< typename T > class atomic { public: // Returns the original value T read_modify_write(F modify, memory_order order = memory_order_seq_cst); }; Usage example: // Saturating increment atomic< int > a; a.read_modify_write([](int n) { return n < std::numeric_limits< int >::max() ? n + 1 : n; }); The implementation could synthesize a CAS loop around the modify function or (ideally) wrap it inside the LL/SC instructions, also in a loop. I believe, in order for this to work the modify function should meet certain requirements: 1. It must not use atomic operations (on this or other variables) or thread synchronization primitives. 2. It must not call functions that might involve context switching (e.g. syscalls, i/o). 3. It should be as small as possible and have the least possible working set (that is the number of accessed variables). 4. It must be prepared to be called multiple times. 5. It must be prepared to receive a value that has never been stored in the atomic variable. The first restriction is essential to avoid deadlocking in case of the emulated (lock-based) atomic<>. Thread synchronization primitives may possibly be using atomic ops internally, so are prohibited as well. The 2 and 3, besides just being something rational one would strive for anyway, are mostly targeted to allow to inject the function call inside the LL/SC pair. It is known that some architectures are very sensitive to what is happening between the LL and SC instructions, so accessing some memory from the modify function or switching the thread context will result in SC always failing and an infinite loop. The 5 would allow to make the first load non-atomic, which can be faster. The CAS or SC instruction will fail if the loaded value was inconsistent. I know there's probably no way to ensure that the function meets these requirements, and it is possible to get an infinite loop in runtime, so maybe always using a CAS loop would be a safer approach, even on an architecture with LL/SC instructions. My hope is that compilers will someday provide intrinsics for this and will be able to generate optimal code, when possible. Does this look interesting to anyone? Comments?

4 7

[AFIO] Formal review
by Giovanni Piero Deretta 02 Sep '15

02 Sep '15

Hi all, This is my review of boost.afio. In fact I have still more comments on the library, but this is taking already too long and I'm well past the review deadline, so I'm sending what I have. I'm hopefully going to post the second part in the next few days. 1. Should Boost.AFIO be accepted into Boost? Please state all conditions for acceptance explicitly. No, not at this time. While the library is potentially quite useful, possibly to larger niche than expected to the author, I have many issues with both the documentation and the API itself, which would need to be resolved before acceptance. To be clear, this is not a conditional acceptance. I believe a full review is warranted to verify that the issues have been addressed. The author is obviously quite experienced in this area (or at least has done a lot of research), so I strongly encourage him to resubmit the library in the future as it has the potential to be be a great contribution to boost. 2. What is your evaluation of the design? My preference, but wouldn't require for acceptance, would be to use ASIO async protocol that leaves the choice of the completion notification strategy to the user . If the library wants all async functions to return futures, it should follow the standard future idioms. First of all, having futures which claim 'standard conformance' and then carry extra hidden error payload is unacceptable. Also functions should take handlers as parameters and not futures. The user should be responsible of explicitly 'then' chaining futures. The library should follow the standard semantics for handle types (i.e. single ownership move only wrappers system handles), and similarly for the future wrappers for such handles (i.e. future<handle>, not shared_future<handle>). Other reviewers have discussed these issues better than I could, so I won't expand further. The dispatcher should probably be called filesystem because that's what it is. The overridable per thread global dispatcher is evil. Functions should take a dispatcher explicitly (or through a handle_ptr) or use a static global dispatcher that represent the global filesystem. Does the library need to distinguish between files and symlinks at open time by calling differently named functions? I'll assume that's the case, but I would like to know the rationale. File, directory, symlink functions should be verbs and called open_file, open_directory, open_symlink. They should return differently typed handles (i.e. file_handle, dir_handle, sym_handle). As an aside, the handle types should have value semantics and be movable. To help generic code, rmdir, rmfile and rmsymbol should be unified under the same function name (rm, or better delete). The parameter type can be used to select the correct overload. Functions that return handles must do so explicitly (i.e. no implicit handle payload). The library should *never* cause the program to crash because of external causes (i.e. files and dirs disappearing or truncated, external locks taken, lock forcibly removed, up to and including disk failure). It is ok to abort on a failed internal consistency check, although it would be nice if the check+abort was encapsulated in an overridable macro (BOOST_AFIO_ASSERT maybe?). It is fine and even encouraged for the check be present even in release builds. The library *must* not suppose that every other program interacting with the filesystem is using AFIO. It is fine if the library were to give some additional guarantees (for example advisory locking becomes non-advisory), but these guarantees should be properly documented. For example, writes in append should be guaranteed atomic no matter what the program doing the writes is doing. In practice, this means that afio should document in detail the implementation of each operation for each backend for each operation so that a knowledgeable user can make the necessary inferences. In practice this seems already to be mostly the case. The documentation has a huge amount of notes on how the various FS and OSs differ and what are the different guarantees. AFIO should provide a standardised set of flags describing the various capabilities and a query interface, so that the inevitable different code paths do not need to be fs name dependent or, worse, #ifdef based. A good starting point for deciding which flags to expose, are the various FS tables scattered through the docs. 3. What is your evaluation of the implementation? I haven't had a chance to do an as in depth evaluation. Additionally, files with thousands of lines do not make it easy to read the code. The git repo contains both v1 and v2 subdirectories, and I'm not sure which one is the one actually under review (the docs say 1.5, not sure which one it is)' A few comments: Overuse of shared_ptr is in my experience code smell as the unclear ownership semantics lead to bugs down the line. The amount of ifdefs is staggering. Most of them are probably necessary, but the number of options that the library can be configured with certainly doesn't help.' It depends on external non-boost libraries, which it seems (but I can't be sure because of the layer of versioning macros) inject names outside the boost::afio namespace, which it shouldn't happen. With two spinlock acquisition per move, the lightweight future/modand seems anything but lightweight. The library should really use boost::future instead of rolling its own. The author should attempt to fold possible improvements directly into boost.thread. Similarly for any necessary improvements to Boost.Asio (for the WoW issue) and Boost.Filesysterm (for boost::path). The abstraction overhead seems excessive, especially for a library suposedly IO bound. The author should at least try to mach the performance of the naive openmp implementation. BTW, nonvolatile ram based storage will be becoming mainstream within the year, so the author might need to revisit very soon the relative cost of various operations. Random suggestions (feel free to ignore these): - look into non temporal stores to help with cache pollution. - have a libnfs backend + NFS over loopback for truly asynchronous filesystem operations (performance is probably going to atrocious). - experiment with the "O_NONBLOCK disk read" patches for the linux kernel. 4. What is your evaluation of the documentation? As noted by others, the documentation does not seem to be of boost standard quality; At times it feels more like a stream of consciousness; often irrelevant or less important information is presented before more important ones. Disquss Comments do not belong in the documentation. With JS disabled, some pictures are not shown, at least in the single page docs. I'm less bothered than others about the 'try AFIO online button'. In fact it would be nice to have such a button after each example (I'm not suggesting that the author should provide it though). Any reference to not-implemented features should removed and at best moved to a separate section at the end of the documentation. A common patters is: "" AFIO implements * A * B (not implemented) * C (not implemented) * D (not implemented)"" which is, honestly, a bit ridiculous. Similarly scattering references to preivious versions of the library all over the documentation is confusing. These should go to a separate history page and/or changelog. The misuse of Terms of Art ('monad' 'precondition') seem a bit worrying. At every occurrence of the term 'filing system' my brain trips. For a while I thought it meant something subtly different from the more common 'filesystem' or 'file system'. This could be just me, so feel free to ignore this unless others complain. The documentation often references C++1z coroutines, which as far as I understand are far from being standardisation ready. It would be better if examples using boost.coroutine, boost.context or even asio.coroutine were provided. ** Intro The first paragraph is a nice introduction, but it should mention prominently that AFIO helps prevents file system races. Move the sub points of bullet 8 to top level, instead deemphatize and sythetize the performance claims under a single bullet. Before claiming performance, describle what the library can do. Reduce any reference to APIBind to a single line (something 'AFIO can be used as a standalone library thanks to APIBind', details elsewhere; also do not claim that APIBind is a boost library). Remove any references to backends from this section. Totaly remove references to unimplemented backands. Supported compilers and platforms, jenkins and uni tests etc do not belong here. Neither do links to dispatch benchmarks. You might want to mention that it is a C++11 library written as part of the GSoC. A reference to ASIO might or might not belong here (No ASIO class or concept seem to be part of the interface). Remove the Batch section from the simple example. Also the rest should stand by itself, without the comments. About the example itself: I find it surprising that you call the results using verbs and operations using names. A better naming convention would be nice. Also in general please prefer type result = op(params); to type result(op(params)); at least when op is an important operation. The initialisation syntax together with the noun based naming convention makes it harder to parse examples. ** Cheat Sheet The frist few paragraphs are interesting, but should go after the table. The table as is not useful, other than an alternate index. I would expecte something like; function name, paramenters, result, very short description. I have no idea what the other columns of the table are trying to convey. The related functionality at the end does not belong here. ** Design Introduction and Rationale In this page I would expect to find an analysis of a generic afio async operation, why a certain interface was chosen, how futures help compose operation, how an operation is implemented internally. For every choice a discussion of the design tradeoff should be presented. Unfortunately, after an interesting "why did I write this library", the chapter loses itself. The version history does not belong here unless is used to justify design choices, but other than saying that previous versions where slower, no other information is conveyed. In particular, at this point of the documentation I would expect a thorough explanation of the concept of a FS race and the minimum guarantees given by the library with respect to file system races. Additionally as the library comes with its own future implementation, a detailed explanations of why boost::futures is not sufficient should be given. As an aside, the author claims that the library is completely lock free, and it would be wait free if not for the the use of spinlocks. This does not makes any sense as the use of spinlocks also make the library *not* lock free, unless the author is using a non-standard meaning for these terms (again see previous comment about misuse of Terms of Art). ** Write Ordering Constraint The explanation on how sync behaves like a barrier and the description of scheduling ordering and dependencies is very useful, and it should be a great starting point for a formal treatment of race freedom. The description of TripleGit is completely unnecessary and should be removed. ** Compilation This section is very confusing. Let' say I want the default (whatever it is) and do not define anything. I get this: After defining your build macros of choice, making latest AFIO available to your code is as simple as: #include "boost.afio/include/boost/afio.hpp" // latest version #include "boost.afio/include/boost/v1/afio.hpp" // specific version if being used standalone or if being used as part of Boost: #include "boost/afio.hpp" // latest version #include "boost/afio/v1/afio.hpp" // specific version I have no idea what any of the above means. ** Boost AFIO Installation into Boost Why is this information not part of the previous chapter? Any reference to non boost.afio should be dropped (except possibly to a link at the end to an external non boost distribution). I understand the the external build instructions are useful for reviewers, but they shouldn't have been part of the documentation under review. ** Supported compilers not much to say here other than, assuming AFIO is accepted, the table would be static and reflect the specific released version instead of trunk. ** Example 1 All references to the macro based versioning should be dropped. I have no idea why the example datastore has to return a monad<shared_ptr<iostream> >. The shared pointer is gratuitous, and for the ""simplest interface" errors can be communicated by exceptions As defined I would expect an interface like this for the simplest store: optional<std::string> read(std::string key) void write(std::string key, std::string content) or something like this for something more complex: some_special_container_range read(std::string key) template<class Range> void write(std::string& key, const Range& range); Possibly the author has in mind something different than a key value system. ** Example 2 Because the interface is non-ideal, it is hard to evaluate the next examples. Freedom from directory renames in nice, but I wouldn't count it very high in the list of requirements for an object store. A dispatcher is introduced, without explanation of what it is. The cheat-sheet mentioned it, but it should be described in more details here. The VM shenigans required to make something like utils::file_buffer_allocator<> work can have serious and hard to pinpoint performance and scalability considerations and shouldn't be presented as a performance win uncritically. The tradeoffs should be discussed. Also read mappings can defeat the point of async IO as the application threads will be subject to blocking page faults. Both previous comments are not trying to suggest that mmap is not useful, but it shouldn't be treated as a transparent optimisation as it can have application wide consequences well outside IO code. As far as I understand boost.afio leaves the choice to the client code and never does mmap behind its back; still the examples should present best practices. The example is too long and has too many distractions. The demonstration a streambuf can be implemented on top of afio is quite interesting, but should be relegated to a separate example. ** Example 3 BOOST_MONAD_PROPAGATE, in addition to being in the wrong namespace, is not documented anywhere (at least a search in the one page doc does not lead anywhere) and seems completely unnecessary. I guess it expands to either a return or a throw. In 'The problems with this naive design', the table does not have unit of measure. The information is interesting, although, without any comparison of durability, concurrency and atomicity guarantees of any of the solution, is hard to infer anything (not that I expect much from a NoSQL db...). ** Example 4 ' Linux is different from other operating systems in that you must explicitly request metadata updates to be sent to physical storage' I'm not an expert, but I thought this was true only for ext3/4 (and only with some, albeit default, mount options) and generally considered broken even by Linus himself. If that's the case might be important to point it out so users can choose other FSs. The atomic key replacement example is nice. Should the library provide pre-made recipes for these kind of uses? In The FS table, the first few column titles should be reworded so that all checkmarks mean that a positive feature is available and 'x'es mean a lack of it. 'This is a good example of where Intel's Hyperthreading can really penalise overall performance sometimes: filing systems tend to parallelise linearly to real CPU core count only.' Why is that the case? I would expect the exact opposite in fact. Are you sure the performance bottleneck is not somewhere else (TLB invalidation, cache misses, badly sized hash lock pools)? ** Example 5 The extent based and append behaviour are great. 'Any writes we make within a 4Kb boundary is probably safe'. 'Probably safe' is not something I want to see when implementing a DB. The example is probably way too complex for a tutorial, also the fact that is incomplete makes it hard to evaluate. ** Hello World Please remove the long comments from the examples. Either make them part of the surrounding explanation or footnotes. ** A less toy example The documentation sometimes claims that AFIO is either faster than dumb stream based IO and sometimes assert that it is slower. Please pick one and stick to it. Or better, do not make any performance claims outside a benchmark page. Performance should not be the biggest claim for AFIO anyway. The example uses stl_future which is not defined anywhere in the documentation as far as I can see. when_all_p(ihs).get(); should probably be when_all_p(ihs_req).get() In general, unless I've completely misunderstood the example, all the .get() calls impose synchronisation, which means that the parallel_concatenate is not as asynchronous as possible. Also it should really schedule handle closes at the end and return a future<void>. for(auto &i : ihs) lasts.push_back(dispatcher->depends(ohresize, i)); The meaning of dispatcher->depend on this code is not obvious at all. From mailing list discussions I assume that depend(future a, bufure b) is a.then([b] { return b; }), but what's the role of the dispatcher here is opaque. Even more surprisingly, a few lines below depend is called as a free function. Also, a few lines above this line is present: when_all_p(ohresize).get(); which should impose an explicit synchronisation, making the depend superfluous. This is the implementation I would like to see: using br = boost::range; auto async_size = [](auto&& name) { return async_info(name).then(auto&& info) { return info.size(); }; }; auto open =[](auto&& name) { reutrn asyn_open(name); }; auto get = [](auto&& future) { return future.get(); }; auto always = [](auto&& x) { return [x=std::move(x)] { return x;}; }; auto unwrap = [](auto&& fr) { std::vector<typename decltype(fr)::value_type> ret; copy_to(ret, mapped(fr, get)); return ret; } template<class PathRange> std::future<std::size> asyn_concat(std::path destname, PathRange&& srcnames) { auto sizes = when_all(br::mapped(srcnames, async_size)) .then(unwrap)).share(); auto total_size = sizes .then([](auto&& range) { return br::accumulate(range.get(), 0);; }); auto srcs_range = when_all(br::mapped(srcnames, open)); auto dest = when_all(async_open(destname), total_size) .then([](auto fdest, auto size ) [] { auto dest = fdest.get(); return async_truncate(dest, size).then(always(dest)); }); return wait_all(srcs_range, dest, fbuffers) .then([](auto&& fsrcs, auto && fdest, auto&& fsizes) { auto&& sizes = fsizes.get(); std::vector<handles> srcs = unwrap(fsrcs); std::vector<std::future<> > writes; struct ctx { off_t offset = 0; ssize_t len = 0; std::vector<char> buf = std::vector<char>(1024*4); }; std::vector<ctx> ctxs; ctx.reserve(src.size()); std::size_t off = 0; auto dest = make_unique(fdest.get()); for(int i = 0; i != src.size(); ++i) { ctxs.push_back({ off, sizes[i] ); off += sizes[i]; auto& ctx = ctxs.back(); auto read = [&ctx, &s = srcs[i]] { if (ctx.len < ctx.buffer.size()) ctx.buffer.resize(ctx.len); ctx.len -= ctx.buffer.size(); return async_read(s, ctx.buffer); }; auto write = [&ctx, &dst = dest.get()] { auto off = ctx.off; ctx.off += ctx.buffer.size(); return async_write(s, off, ctx.buffer); }; auto read_write = [&ctx, read, write](auto self){ if(ctx.len) return read().then(write).then(self); return make_ready_future(); }; writes.push_back(read_write(read_write)); } return wait_all(writes).then( [ctx=std::move(ctx), dst=std::move(dst), src=std::move(src)] { return wait_all( mapped(srd, [](auto&& s) { return async_close(s); }) .then([d = async_close(dst)] { return d; })) }); }); }; Note that everything is perfectly parallel and dependencies are minimal. Most operations use unique semantics except for 'sizes' where I didn't bother to do better. The lifetimes of buffers and handles in the read/writes are admittedly subtle, but not too much. Instead of creating N futures per file, I'm creating just a single one at a time. ** (all examples) Overall the examples are nice, the progression of additional features makes sense. The code should be cleaned up to remove superflous code. Comments should be removed and the code should be discussed in the prose (possibly referencing line numbers). I suggest that the strawman interface using iostream is removed. The lookups should simply return initially optional<string>, then future<string>. future<string> (or future<vector<char> >) of course does not work well for large buffers. You could return something like future<chunk>, where chunk has the following interface: struct chunk { const char * begin(); const char * end(); std::size_t size(); // an empty chunk means we are done future<chunk> next(); // invalidates this }; but the reality is that futures are not great for lazy streams. You could look into reactive streams, but that's another can of worms. For pure read/writes I suggest an asio-like interface which uses callbacks would be optimal and readily familiar to boost users. 5. What is your evaluation of the potential usefulness of the library? I had never had a chance to look at the library in the past, and my only impressions of it came by the many references and claims made by the author in the boost mailing list. In particular I was baffled by the author's claim that the ASIO callback interface is not adequate for file IO. I could not understand how async read/writes from a file could be so significantly different from socket io. Turns out that the actual I/O part is just a small part of the library, and the async part even less. The bulk of the library is about writing roboust filesystem manipulations. In my mind, where boost.filesystem is designed as a simple interface to file system operations for script-like programs, AFIO attempts to be the goto interface for robust applications. 6. Did you try to use the library? With what compiler? Did you have any problems? I didn't trey to compile or use the library. 7. How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? An in depth study of the documentation. I didn't keep track of the hours, probably 10 or more. 8. Are you knowledgeable about the problem domain? Asynchronous File IO? No. Race free file IO? Neither, but had to deal with these kind of issues in the past. Something like AFIO might have been useful.

2 1

[afio] Formal review of Boost.AFIO
by Ahmed Charles 02 Sep '15

02 Sep '15

The formal review of the Boost.AFIO library starts, August 21st and ends on Monday August 31st. Boost.AFIO provides a portable API implementing synchronous and asynchronous race-free filesystem and scatter-gather file i/o. It requires a minimum of C++ 11. It has minimum dependencies on a Filesystem TS and a Networking TS implementation (e.g. Boost.Filesystem and Boost.ASIO). Backends are provided for the Windows NT kernel and POSIX. The utility of a portable library providing strong concurrent race guarantees about filesystem and file i/o can be seen in its tutorial where a transactional ACID key-value store is built from first principles. Boost.AFIO was brought to Boost as part of GSoC 2013 and Niall Douglas has continued to develop and improve the library since then, generating two internal implementation libraries Boost.APIBind and Boost.Monad which are expected to be separately brought for Boost review in 2016. The documentation can be found here: https://boostgsoc13.github.io/boost.afio/doc/html/afio.html The source code can be found here: https://github.com/BoostGSoC13/boost.afio/tree/boost-peer-review Online web compiler playpen can be found here: http://melpon.org/wandbox/permlink/DR8wCpu5Rl20GMdM? Please answer the following questions: 1. Should Boost.AFIO be accepted into Boost? Please state all conditions for acceptance explicity. 2. What is your evaluation of the design? 3. What is your evaluation of the implementation? 4. What is your evaluation of the documentation? 5. What is your evaluation of the potential usefulness of the library? 6. Did you try to use the library? With what compiler? Did you have any problems? 7. How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? 8. Are you knowledgeable about the problem domain?

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[AFIO] Formal review
by Antony Polukhin 01 Sep '15

01 Sep '15

> 1. Should Boost.AFIO be accepted into Boost? This library must be in Boost, but not in it's current state. Some polishing required and some improvements. Dependent libraries must be accepted in Boost/dropped/documented and reviewed as part of AFIO. After that another review must be done. So it's NO for now. > 2. What is your evaluation of the design? NONBACTH operations seem right and good. Some simplification must be applied, by possibly removing some of the overloads and reducing amount of types visible to user (`handle_ptr`, `*_req`). BATCH operations do not seem right. They must be removed or their interface must be greatly reworked. afio::path must be hidden from user or filesystem::path must be used (I'm not 100% sure, but it looks like `\\?\` paths are OK to be in filesystem::path http://www.boost.org/doc/libs/1_59_0/libs/filesystem/doc/reference.html#lon… ). More functions for everyday use may be provided (async_copy for example) > 3. What is your evaluation of the implementation? Header files must be split into multiple smaller ones. Multiple memory allocations must be removed from library internals. Implementation must be polished. Recommendation: ABI stable part of AFIO may be moved in a separate git branch to untie the AFIO library developer's hands. In that case new version of AFIO may break the ABI without affecting users and older versions could be removed from sources. > 4. What is your evaluation of the documentation? That's one of the biggest problems of the library. Documentation is not structured and sometimes overcomplicated. Some notes for simplification: * "AFIO single page cheat sheet for the very impatient" -> "Getting started". Move table to the top of the page, replace the "Related types" column with "Boost.Filesystem sync alternative", replace numbers with checks/+/-. * Move the "Example mini-programs written using AFIO" chapter right after the "Getting started", rename chapter into "Tutorial", refactor second example to not use batch operations and to use only free standing functions. Third and fourth examples must be greatly simplified and probably split into smaller examples. * Move the content of "Step by step workshop building an AFIO-based key-value store" into the "Tutorial" after the previous examples, rename it into "Key-value store walkthrough", simplify and make shorter if possible * "Compilation" section must be somewhere around "Getting started" * Other docs must be after the "Getting Started," "Tutorial" and "Compilation" * "Reference" section must be refactored. All the overloads must be probably described and showed on a single page (all the overloads, including those that explicitly accept dispatcher) * Shorten and simplify the examples wherever possible. > 5. What is your evaluation of the potential usefulness of the library? Very very useful. > 6. Did you try to use the library? No. > 7. How much effort did you put into your evaluation? About 20 hours. > 8. Are you knowledgeable about the problem domain? I have a fair amount of experience with asynchronous programming in C++ and I have pretty extensive experience with designing interfaces for async operations. Have not dealt with async fiesystem operations before. -- Best regards, Antony Polukhin

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[math] lcm errors
by Damian Vicino 31 Aug '15

31 Aug '15

Hi, I found out, lcm (RT) is silent about errors. (the bad way) Is there any way to activate them? For example, the following code: #include<iostream> #include <boost/math/common_factor.hpp> int main () { int a = 1<<30; int b = 3; int c = boost::math::lcm(a, b); std::cout << "lcm of :" << a << " & " << b << " is " << c << std::endl; return 0; } Obtains the following result: lcm of :1073741824 & 3 is 1073741824 Which is not the right answer (because it is not divisible by 3), but neither it raised an exception or returned some special value. Is there any way I can make it raise an exception? I guess I could check everywhere it as: if (c%a != 0 || c%b != 1) throw std::exception(); But probably there is something implemented that I couldn’t find in the documentation. Best regards, Damian

2 1

[asio] MSVC compiler error when compiling urdl
by Christian Henning 31 Aug '15

31 Aug '15

So URDL (https://github.com/chriskohlhoff/urdl ) is not part of boost, I know. But a nasty MSVC 2013 compiler error prevents the most simple code to compile. #define _WIN32_WINNT 0x0601 #define URDL_HEADER_ONLY 1 #define URDL_DISABLE_SSL 1 #include <urdl/istream.hpp> #include <boost/progress.hpp> #include <iostream> #include <fstream> int main(int argc, char* argv[]) { return 0; } The fix is relatively simple but it would change code is asio's handler_invoke_helpers.hpp. Basically change: using boost::asio::asio_handler_invoke; asio_handler_invoke(function, boost::asio::detail::addressof(context)); to boost::asio::asio_handler_invoke(function, boost::asio::detail::addressof(context)); I'm using VC2013. I'm using master branch of boost. Regards, Christian

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Re: [boost] [afio] Formal review of Boost.AFIO
by Sebastian Theophil 31 Aug '15

31 Aug '15

-- Dr. Sebastian Theophil | stheophil(a)think-cell.com<mailto:stheophil@think-cell.com> Senior Software Engineer We are looking for C++ Developers: http://www.think-cell.com/career ________________________________ think-cell Software GmbH http://www.think-cell.com<http://www.think-cell.com/> Chausseestr. 8/E phone / fax +49 30 666473-10 / -19 10115 Berlin, Germany US phone / fax +1 800 891 8091 / +1 212 504 3039 Amtsgericht Berlin-Charlottenburg, HRB 85229 | European Union VAT Id DE813474306 Directors: Dr. Markus Hannebauer, Dr. Arno Schödl On 27 Aug 2015, at 04:45, boost-request(a)lists.boost.org<mailto:boost-request@lists.boost.org> wrote: Ok, let's revisit the original pattern code I mentioned: EXAMPLE A: shared_future h=async_file("niall.txt"); // Perform these in any order the OS thinks best for(size_t n=0; n<100; n++) async_read(h, buffer[n], 1, n*4096); Niall, is parallel read (parallel writing maybe?) the only use-case where you want a shared_future? If I understand Thomas correctly, he doubts you need the shared_future semantics because one async operation hands down a single handle to the next continuation. Essentially something like: async_file(“niall.txt”) .async_read(buffer, length_to_read) .async_truncate(length_to_read) .async_close() Your counter example was an asynchronous *and* parallel read where you need to share the file handle (or rather the future<handle>) between parallel reads. Shouldn’t this be abstracted away in the API somehow? I can’t think of many file operations you want to do N times in parallel. Truncating a file in parallel several times doesn’t seem to make much sense :-) So why not make it: async_file(“niall.txt”) // Read 100 times asynchrnously and in parallel and provide lambda returning n-th buffer and offset: .async_parallel_read(100, [&](int nCount) { return std::make_pair(buffer[n], n*4096; }) .async_truncate(length_to_read) .async_close() The 100 reads are internally not ordered but they can only begin once the file has been opened, they consume this handle together, and only after all reads are complete can we truncate. Is this not what you’re trying to do? Regards Sebastian

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[AFIO] Review (or lack of it)
by Roland Bock 31 Aug '15

31 Aug '15

Hi, I vote for "No, the library should not be accepted". I do not vote this way because the library is bad. I do so because I have no way of telling. a) There is so much going on about personal hardships (e.g. hundreds of hours of family time and 12-4am sessions and fried disks and no electricity and suspected vendettas and supposedly useless reviews). None of this has anything to do with a library review. Why mention it, even if you feel it? All of this is bound to make it hard to be impartial. b) AFIO depends on other libraries which are probably going to be proposed for boost, but are not in yet. Regardless of whether there is a precedent or not, this is far from being ideal. Judging by the discussion about "Monad", getting that library into boost is not just a mere formality. Thus, Monad implicitly IS part of the review, because if it is not accepted (which we don't know today), it will become part of AFIO. Thus, the scope of the review is not defined correctly. c) There are older versions in there. There is 1.3 and 1.4 at least (are there more?). Please choose one. Go for it. Of course, boost libraries evolve over time. There will be new versions of the interface. But starting with that kind of baggage? And asking for a review that necessarily has to cover everything that is currently available? d) The implementation of 1.4 will be replaced completely. Thus, the implementation (which I consider an important part of the review), cannot be reviewed in any way that is worth anyone's time. e) Documentation * Please drop the "using namespace XYZ" from all examples. Maybe use namespace aliases. * The "cheat-sheet" for the impatient is beyond me. I have no idea what it is trying to convey. * I would certainly prefer ONE page with planned features, not sprinkled info here and there (especially not on the cheat sheet). * Redundancy: For example, all the dir() functions share the same example, don't they? I haven't done a diff and I won't. But it makes me nervous to see the same example over and over again. Why not make one page explaining all the dir() functions and then use ONE example? Also the "Note that ..." text seems to be the same on all pages. This piles up to wonderfully large amounts of documentation, but I have no intention to reading all of that ever repeating stuff trying to find the needle in the haystack that actually contains different information. This has to be condensed. * There are deprecated functions? Again, I strongly recommend to start without the extra baggage. * The mix of history and rationale is hard to read, IMO. I'd be interested in the rationale, but not in the many steps it took to get there. * I do not get the world's simplest blob store in the STL form. It is most definitely not the simplest blob store. Not even the simplest persistent blob store. Why would I need a monad there? Why is there a writable flag (why isn't constness enough to prevent writing)? Why isn't the directory created at construction once and for all? BTW: The name validation fails to check for empty string. * https://boostgsoc13.github.io/boost.afio/doc/html/afio/quickstart/workshop/… mentions AFIO v1.40 (thats 36 numbers in the future). If the pictures are not loaded, the performance numbers in the table do not say what they are (the per sec is missing). * "The /final/ named blob store design" starts with "Caution: This section was not finished". * "The performance of and problems with this third generation design" consists of "This section was not completed in time[...]" * So basically the crucial parts of the blob store sequence are incomplete at best. f) Code (since the implementation is going to change anyway, this might all be useless): * /attic: Seriously? * I am not a big fan of #if 0 in release code * I doubt that std::cerr should be in this library's code. * I wonder why there really is a need to have your own path stuff on top of boost::filesystem. If boost::filesystem is insufficient, wouldn't it be better to contribute to that one? Haven't looked too closely, though. * I looked briefly into detail/. I would not want to look for a bug there. I have not done any detailed analysis to base this on, but: I would assume that with some refactoring (moving the platform specific parts into platform specific headers), the readability could be increased dramatically. Again: This is just a guess. In the current situation, I cannot do a formal review that would result in acceptance. I recommend to treat the current review period as a pre-review and * Do a review of Monad (or whatever it will be named) first, maybe API Bind, too, depending on whether that is going to be used in AFIO * Remove all old versions, everything deprecated and do the implementation change that is planned * Cleanup the documentation. Get it read by people with different knowledge of the problem domain. I am willing to read it as somebody who is interested but certainly not very knowledgeable. * Let the dust settle a bit * Start a new review * Even if you believe in vendettas, stay calm and answer in a matter-of-fact way. My experience with the boost list is, that there are strong voices here which have a very finely tuned sense of fairness. I did invest several hours in this review, reading the mail threads, reading the documentation, looking through some code, writing this mail. As stated above, I do consider myself interested but not very knowledgeable in the problem domain. I would like to see a library for asynchronous file IO in boost, but I don't think AFIO is ready yet. Regards, Roland

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[afio] running tests
by Michael Caisse 30 Aug '15

30 Aug '15

Hi Niall - I'm trying to run the tests. I'm certain I am just doing something really silly... input is welcome! I have dropped the AFIO repo into a libs/afio directory for the super project. I ran ./b2 headers which linked in the boost/afio bits. I then go to libs/afio/test and execute "b2 release" which unfortunately results in: find: libs/afio: No such file or directory Performing configuration checks ... This is the same way I run other library tests and those are working as normal. Is there some other setup step that I'm forgetting? Thanks! michael -- Michael Caisse ciere consulting ciere.com

4 4

AFIO review response
by Hartmut Kaiser 30 Aug '15

30 Aug '15

This is my (sadly very short) AFIO review. I vote NO (to not accept) the library into Boost as I'm not able to tell whether the library is useful and fit for Boost. Reason: I tried to understand the design and rationale of the library and asked a number of questions on this list to clarify things I didn't understand. Sadly, the author decided not to answer a single of my questions (not even did he directly respond to any of my emails). I'm not able to make an educated decision on any of the review criteria without having the questions answered which I asked. The reason I send my review now is that I have to make this decision today. I'll not be able to spend any more time on this before the review period ends. So far, I have invested a couple of hours reading through the documentation, following the email threads, and thinking about the design I saw. Regards Hartmut --------------- http://boost-spirit.com http://stellar.cct.lsu.edu

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[android][regression] bjam failed
by Dmitry Moskalchuk 30 Aug '15

30 Aug '15

Hello, Today I've experienced problems with Android regression tests on 'develop' ('master' is OK, and 'develop' was OK too for long time): ERROR: Bjam failed (see /home/cislave/.crystax/ci-boost/regression/android-21-armeabi-v7a-hard-develop/test/develop/regression/armeabi-v7a-hard/test/results/bjam.log for full details): - BOOST_OS_LINUX == 0 : yes - BOOST_COMP_GNUC >= 4.7.4 : no - BOOST_COMP_GNUC >= 4.3.0 : no - BOOST_COMP_GNUC >= 4.3 : no - BOOST_OS_QNX == 0 : yes - zlib : yes warn: Unable to construct ../libs/predef/test/info_as_objcpp warn: Unable to construct ../libs/predef/test/info_as_objc error: Name clash for '<p/home/cislave/.crystax/ci-boost/regression/android-21-armeabi-v7a-hard-develop/test/develop/regression/armeabi-v7a-hard/test/boost_root/bin.v2/libs/dll/test>libtest_library.so.1.59.0' error: error: Tried to build the target twice, with property sets having error: these incompatible properties: error: error: - <cxxflags>-Wall -Wextra -pedantic -Wno-long-long <library>object(file-target)@57008 <library>object(file-target)@57040 <toolset-gcc:version>4.9 <toolset>gcc <xdll-path>/home/cislave/.crystax/ci-boost/regression/android-21-armeabi-v7a-hard-develop/test/develop/regression/armeabi-v7a-hard/test/results/boost/bin.v2/libs/filesystem/build/gcc-4.9/release/abi-aapcs/target-os-android/threading-multi <xdll-path>/home/cislave/.crystax/ci-boost/regression/android-21-armeabi-v7a-hard-develop/test/develop/regression/armeabi-v7a-hard/test/results/boost/bin.v2/libs/system/build/gcc-4.9/release/abi-aapcs/target-os-android/threading-multi error: - <library>object(file-target)@332654 <library>object(file-target)@332686 <toolset-clang:platform>linux <toolset-clang:version>3.6 <toolset>clang <xdll-path>/home/cislave/.crystax/ci-boost/regression/android-21-armeabi-v7a-hard-develop/test/develop/regression/armeabi-v7a-hard/test/results/boost/bin.v2/libs/filesystem/build/clang-linux-3.6/release/abi-aapcs/target-os-android/threading-multi <xdll-path>/home/cislave/.crystax/ci-boost/regression/android-21-armeabi-v7a-hard-develop/test/develop/regression/armeabi-v7a-hard/test/results/boost/bin.v2/libs/system/build/clang-linux-3.6/release/abi-aapcs/target-os-android/threading-multi error: error: Please make sure to have consistent requirements for these error: properties everywhere in your project, especially for install error: targets. Does anyone know what that means and how to fix it? I suspect this is result of recent update related to Boost.Dll, but I don't know if that's error in our scripts, preparing testing environment, or error in Boost itself. -- Dmitry Moskalchuk

1 0

[Proposal] BOOST_NO_GLOBAL_FILESYSTEM_NAMESPACE
by Ed Schouten 30 Aug '15

30 Aug '15

Hi there, I'm currently in the process of porting the Boost libraries to a new platform called CloudABI. CloudABI is a POSIX-like runtime environment that is purely built on the concept of capability-based security. In a nutshell, it means that actions that have side-effects outside of a process can only be performed if the process owns a capability (a file descriptor). In other words, open() is missing, but openat() is still there. There are only local filesystem namespaces. CloudABI allows you to reduce the impact of security exploits through sandboxing, but also makes it possible to safely run untrusted third-party applications without requiring any virtualization, containers, etc. Be sure to check out the GitHub page for more details: https://github.com/NuxiNL/cloudlibc The other day I started experimenting with getting Boost working on CloudABI and I noticed that most of the Boost sources already build on CloudABI. I somewhat expected this, because Boost sources tend to be written in a loosely coupled, testable way. But still, hats off to the Boost developers! The biggest showstopper -- as expected -- is boost::filesystem, which will likely never work on CloudABI: https://groups.google.com/a/isocpp.org/forum/#!msg/std-proposals/q1F0KDEBtf… But in many cases there are also classes that can optionally access the filesystem through utility functions (boost::locale::gnu_gettext, boost::program_options::parse_config_file(), etc). The reason why I'm sending this email is because I want to propose adding a new configuration option, BOOST_NO_GLOBAL_FILESYSTEM_NAMESPACE, that I can use to conditionally disable such utility functions. I've attached a patch for Boost.Config to this email. Does this approach seem reasonable? Do we like the name of this build option? Does the patch look all right? It seems as if generate.cpp also made some unnecessary changes to these files. What's up with that? Best regards, -- Ed Schouten <ed(a)nuxi.nl> Nuxi, 's-Hertogenbosch, the Netherlands KvK-nr.: 62051717

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Re: [boost] [afio] AFIO review postponed till Monday
by Glen Fernandes 29 Aug '15

29 Aug '15

Did the review start yesterday? Glen

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Request for help in porting colony to boost from experienced container boost dev
by Soul Studios 29 Aug '15

29 Aug '15

Hi all- I require help in adapting colony to the boost framework, as colony is light on dependencies, as per the boost recommendations, whereas the boost containers are extremely dependency-heavy - which is somewhat confusing. I need somebody who has some experience with writing or editing the boost containers, to help me sort this from that, wrong practice from right practice in this area. It is, perhaps, something I could spend half a year trying to understand, but unfortunately I do not have that luxury. Whoever helps me will of course get credit for their involvement, with my gratitude. If yourself or anyone you know can help, please get them or yourself in touch. If anyone is interested, my initial port of colony to boost is at the following github repository: https://github.com/mattreecebentley/boost_colony It is an incomplete port but functional. I posted to the boost-users list about colony previously, if anyone is unsure about what it is please see the website (plflib.org) for benchmarks, overview reasoning and code- Thanks, Matt

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Merging pull requests in boostorg/boost
by Antony Polukhin 28 Aug '15

28 Aug '15

Hi, Could someone review and merge the following pull request https://github.com/boostorg/boost/pull/94 ? I do hope to see Boost.DLL in next release, but that requires a lot of testing on different platforms (and that requires the pull request merged). There are also some pending Boost.Compute pull requests, please take a look at them too. -- Best regards, Antony Polukhin

1 0

Feature macro for putting things in the std namespace
by Mathias Gaunard 28 Aug '15

28 Aug '15

Hi all, I'm working on providing support in Boost for a new standard library provider, which happens to put some but not all of its symbols in the 'std' namespace. As a result, opening the 'std' namespace and forward-declaring or specializing things would not work. It seems a number of Boost libraries do this (most notably Boost.Container), with special code to deal with libc++ (since libc++ puts everything under an inline namespace). I think it would make more sense to have a BOOST_HAS_SYMBOLS_IN_STD_NAMESPACE feature macro that one could check to tell whether it is possible or not to do that. In the case of forward-declarations, the library would have to fall back to including the appropriate headers if that feature macro is not set. Is everyone on board with this? Any recommendation for the name?

4 8

Interest in adding support for the Bloomberg Standard Library
by Mathias Gaunard 28 Aug '15

28 Aug '15

Bloomberg has its own C++ standard library, BSL, which sits on top of another standard library but replaces containers with their own versions. The BSL containers are somewhat similar to Boost.Container's: they provide stateful allocators, as well as backport some C++11 extensions to C++03. Before I make all the necessary changes and do a pull request, I would like to make sure the Boost community would be ok in including support for this in Boost.Config. This library is fairly specific to one company and not used much elsewhere, despite being open-source (<https://github.com/bloomberg/bde>). We are also trying to phase out usage of this library with the 'std' namespace (it can be configured to use the 'bsl' namespace instead), but that's likely not going to happen anytime soon. As part as providing support for this in Boost, we would also be providing testers, mostly on big iron unix (AIX-powerpc, SunOS-sparc). Any interest?

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Re: [boost] [Boost-users] [afio] Formal review of Boost.AFIO
by Niall Douglas 28 Aug '15

28 Aug '15

On 25 Aug 2015 at 8:17, Robert Ramey wrote: > > Please answer the following questions: > > > > 1. Should Boost.AFIO be accepted into Boost? Please state all > > conditions for acceptance explicity. > > > > Provisionally, yes. > > > > Requirements: > <snip> > > This list of requirements constitutes much more than a "a few changes". > It's impossible to know what what the library would like like after > all these changes and and their repercussions were addressed. I don't > think we can realistically expect the review manager to verify that and > library with all these changes is sufficiently close the current one to > take responsibility for signing off on the final version. I read the provisional yes as meaning yes to how the library is roadmapped to look like in the future, and he recommends an additional mini-review at that point which could introduce yet another mini-review after again. In other words, he's saying fundamentally it's good, but needs a lot more work yet. Paul please do correct me if I am wrong in this interpretation. There is precedent for this: Boost.Fiber was provisionally approved here as a C++ 98 library with condition of a mini-review before entry. Boost.Fiber is now a C++ 14 library and sufficiently different from the library originally reviewed it may require a second mini-review if during its first mini-review it is felt still lacking. I think this pattern of repeated mini-reviews caused by changes to the common implementations of the C++ standard rather than the libraries themselves is going to be very common next few years. All these changes to AFIO are almost entirely driven by changes since 2012 to the various WG21 technical standards. If they hadn't changed and C++ compilers (specifically MSVC) hadn't changed, AFIO wouldn't have changed. It's very similar for Fiber, which had to be refactored in the face of substantial changes in C++ 14. Niall -- ned Productions Limited Consulting http://www.nedproductions.biz/ http://ie.linkedin.com/in/nialldouglas/

7 16

[http] Formal review of Boost.Http
by Bjorn Reese 28 Aug '15

28 Aug '15

Dear Boost and ASIO communities. The formal review of Vinícius dos Santos Oliveira's Boost.Http library starts today, August 7th and ends on Sunday August 16th. Boost.Http is designed for various forms of modern HTTP interaction, from normal HTTP request, over HTTP chunking and pipelining, to upgrading to other web protocols like WebSocket. This library builds on top of Boost.ASIO, and follows the threading model of ASIO. The two basic building-blocks are http::socket, which is socket that talks HTTP, and http::message with contains HTTP meta-data and body information. You can use these building-blocks to build a HTTP server that fits your exact needs; for instance, an embedded HTTP server for a ReST API. Boost.Http comes with a light-weight HTTP server and a static file server. Currently, Boost.Http is limited to server-side interaction, but the design principles used extends to client-side as well. Boost.Http was originally developed as part of GSoC 2014 and Vinícius has continued to develop and improve the library since then. The documentation can be found here: http://boostgsoc14.github.io/boost.http/ The source code can be found here: https://github.com/BoostGSoC14/boost.http The source code is build using CMake, but Boost.Build is in the pipeline (already done for documentation.) Please answer the following questions: 1. Should Boost.Http be accepted into Boost? Please state all conditions for acceptance explicity. 2. What is your evaluation of the design? 3. What is your evaluation of the implementation? 4. What is your evaluation of the documentation? 5. What is your evaluation of the potential usefulness of the library? 6. Did you try to use the library? With what compiler? Did you have any problems? 7. How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? 8. Are you knowledgeable about the problem domain?

17 58

[http] Boost.Http review report
by Bjorn Reese 28 Aug '15

28 Aug '15

The outcome of the formal review of Boost.Http is that the library is NOT accepted for inclusion into Boost this time. Below I will first summarize the main themes running through the review, and afterwards I will make some recommendations about how to proceed from here. The following reviews were posted: - Antony Polukhin: No - Darren Cook: No - David Sankel: No - Lee Clagett: No - Niall Douglas: Yes, conditionally - Roland Bock: No - Tom Kent: No The discussions were constructive and offered much valuable feedback. There was a general consensus that Boost ought have a HTTP library, but that Boost.Http was too incomplete in its present state. Many reviewers mentioned the disconnect between their expectations and what the library offered. There were several suggestions for alternative names for the library to better reflect the feature-set it offers. Boost.Http currently only provides a server-side API, but the reviewers felt that a client-side API would be usable to more users. There was also a recurring request for Boost.Http to be a header-only library. The HTTP parser currently used is not header-only and that is the main obstacle towards a header-only Boost.Http library. Some of the discussion revolved around what level of abstraction would be appropriate for Boost.Http. The views ranged from wanting higher- level APIs all the way down to simply wanting a HTTP parser/generator and then leave all the socket and buffer management up to the user. Regarding the HTTP parser/generator, there is no reason why it cannot be a separate Boost library. However, Vinicius correctly pointed out that this is insufficient for a HTTP server framework that handles multipleback-ends (e.g. HTTP/2, FastCGI, or WebSocket). By implication it cannot handle HTTP upgrade requests either. Some reviewers also felt that HTTP/2 should be part of Boost.Http, partly because that would demonstrate the extensibility of the current design, and partly because the library would be in a stronger position to attract users if it offers more than its competitors. There was concern about whether or not the Boost.Http API can be extended to HTTP/2. The main challenge with HTTP/2 is fitting multiplexing into the API. Vinicius suggested that there should be a http::socket per multiplexed channel, so it will be transparent to the user if several of his http::sockets to the same remote endpoint are transported via the same TCP socket. This will keep the API clean when extended to HTTP/2. Boost.Http currently creates an associative array for all header fields. One reviewer explored the idea of using an incremental (push or pull) HTTP parser as part of the API to let users decide which header fields to copy and which to discard. There was a general consensus that more examples are needed, and that the tutorial should have smaller examples. The Boost.Http code base currently builds with CMake. This must be converted into Boost.Build before being integrated into the Boost code base. Several other third-party tools were suggested, but as these are not requirements for inclusion into Boost I will leave the decision to the author. As for the future, I hope that Vinicius is not too discourage by the current rejection, and that he will consider re-submitting the library at a later stage. Judging from the reviews, the following additions will make a future submission more likely to succeed: 1. Involve the community more during the development. This will both solicit earlier feedback on the design, and help to align community expectation. 2. Provide a client-side API. 3. Design higher-level APIs on top of the low-level APIs. 4. Better documentation and more examples. I also hope that people in the community will consider contributing to the library. For example, a good opportunity is to help creating the higher-level APIs. Another opportunity is to help with the (header- only, possibly incremental) HTTP parser/generator, which could be a separate library.

4 3

[trac] Adding notification for component
by Edward Diener 28 Aug '15

28 Aug '15

I have a few trac questions. Who is the trac administrator ? How does one change the default person who is assigned a trac ticket for a particular Boost library ? How does one get added as a notification for a particular Boost library activity on Trac ? How do I add vmd as a component/library in trac ?

3 3

[website] [log] Add a patch to 1.59 release notes
by Andrey Semashev 27 Aug '15

27 Aug '15

Hi, Unfortunately, Boost.Log in Boost 1.59 contained a serious bug that affected many users (I got multiple reports already): https://svn.boost.org/trac/boost/ticket/11549 There's a fix in develop, and it went through some testing (including my manual test runs): https://github.com/boostorg/log/commit/7da193fde1a9c1bc925ee980339f4df2e1a6… Is it possible to add a patch from this commit and a link to the ticket to the 1.59 release notes? PS: You can download the patch if you add ".patch" to the above link: https://github.com/boostorg/log/commit/7da193fde1a9c1bc925ee980339f4df2e1a6…

2 3

[filesystem] Relative Draft Proposal RFC
by Beman Dawes 27 Aug '15

27 Aug '15

There have been requests for a Filesystem library relative function for at least ten years. The requested functionality seems simple - given two paths with a common prefix, return the non-common suffix portion of one of the paths such that it is relative to the other path. In terms of the Filesystem library, path p("/a/b/c"); path base("/a/b"); path rel = relative(p, base); // the requested function cout << rel << endl; // outputs "c" assert(absolute(rel, base) == p); If that was all there was to it, the Filesystem library would have had a relative function years ago. Critical issues: Clashing requirements, symlinks, directory placeholders (dot, dot-dot), user-expectations, corner cases. A paper by Jamie Allsop, Additions to Filesystem supporting Relative Paths, is what broke my mental logjam. Much of [my proposal] is based directly on Jamie's analysis and proposal. The weakly_canonical function and aspects of the semantic specifications are my contributions. Mistakes, of course, are mine. The full proposal is at http://boostorg.github.io/filesystem/relative_proposal.html A preliminary implementation is available in the feature/relative2 branch of the Boost Filesystem Git repository. See github.com/boostorg/filesystem/tree/feature/relative2 The overall plan is to get feedback from boost developers, then merge to develop for boost 1.60, then propose to the C++ committee for addition to the Filesystem TS. Comments welcome. If you are one of the many people who have requested "relative" functionality, does this proposal meet your needs? If not, why? Thanks, --Beman

1 1

[iterator] Regenerating the iterator docs
by Edward Diener 26 Aug '15

26 Aug '15

I have updated a very small portion of the iterator docs and now I need to regenerate the documentation. Evidently despite iterator having quickbook documentation the actual documentation presented to end-users is created from RST files, python scripts, and make files. But I do not see the process of regenerating the docs explained anywhere so I am wondering if anyone knows how to do it. I tried 'python generate.py' on Windows but this led to the error: > make counting_iterator.html facade-and-adaptor.html filter_iterator.html functio > n_input_iterator.html function_output_iterator.html index.html indirect_iterator > .html pointee.html iterator_adaptor.html iterator_facade.html new-iter-concepts. > html permutation_iterator.html reverse_iterator.html transform_iterator.html zip > _iterator.html iterator_archetypes.html iterator_concepts.html iterator_traits.h > tml counting_iterator.pdf facade-and-adaptor.pdf filter_iterator.pdf function_in > put_iterator.pdf function_output_iterator.pdf index.pdf indirect_iterator.pdf po > intee.pdf iterator_adaptor.pdf iterator_facade.pdf new-iter-concepts.pdf permuta > tion_iterator.pdf reverse_iterator.pdf transform_iterator.pdf zip_iterator.pdf i > terator_archetypes.pdf iterator_concepts.pdf iterator_traits.pdf > executing: 'make counting_iterator.html facade-and-adaptor.html filter_iterator > .html function_input_iterator.html function_output_iterator.html index.html indi > rect_iterator.html pointee.html iterator_adaptor.html iterator_facade.html new-i > ter-concepts.html permutation_iterator.html reverse_iterator.html transform_iter > ator.html zip_iterator.html iterator_archetypes.html iterator_concepts.html iter > ator_traits.html counting_iterator.pdf facade-and-adaptor.pdf filter_iterator.pd > f function_input_iterator.pdf function_output_iterator.pdf index.pdf indirect_it > erator.pdf pointee.pdf iterator_adaptor.pdf iterator_facade.pdf new-iter-concept > s.pdf permutation_iterator.pdf reverse_iterator.pdf transform_iterator.pdf zip_i > terator.pdf iterator_archetypes.pdf iterator_concepts.pdf iterator_traits.pdf' > make: Nothing to be done for `counting_iterator.html'. > make: Nothing to be done for `facade-and-adaptor.html'. > make: Nothing to be done for `filter_iterator.html'. > make: Nothing to be done for `function_input_iterator.html'. > make: Nothing to be done for `function_output_iterator.html'. > make: Nothing to be done for `index.html'. > make: Nothing to be done for `indirect_iterator.html'. > make: Nothing to be done for `pointee.html'. > make: Nothing to be done for `iterator_adaptor.html'. > make: Nothing to be done for `iterator_facade.html'. > make: Nothing to be done for `new-iter-concepts.html'. > make: Nothing to be done for `permutation_iterator.html'. > make: Nothing to be done for `reverse_iterator.html'. > make: Nothing to be done for `transform_iterator.html'. > make: Nothing to be done for `zip_iterator.html'. > make: Nothing to be done for `iterator_archetypes.html'. > make: Nothing to be done for `iterator_concepts.html'. > make: Nothing to be done for `iterator_traits.html'. > make: Nothing to be done for `counting_iterator.pdf'. > make: Nothing to be done for `facade-and-adaptor.pdf'. > make: Nothing to be done for `filter_iterator.pdf'. > make: *** No rule to make target `function_input_iterator.pdf'. Stop. > Traceback (most recent call last): > File "generate.py", line 30, in <module> > syscmd('make %s' % ' '.join(all)) > File "C:\Programming\VersionControl\modular-boost\libs\iterator\doc\syscmd.py" > , line 14, in syscmd > repr(s), err) > SystemError: command: 'make counting_iterator.html facade-and-adaptor.html filte > r_iterator.html function_input_iterator.html function_output_iterator.html index > .html indirect_iterator.html pointee.html iterator_adaptor.html iterator_facade. > html new-iter-concepts.html permutation_iterator.html reverse_iterator.html tran > sform_iterator.html zip_iterator.html iterator_archetypes.html iterator_concepts > .html iterator_traits.html counting_iterator.pdf facade-and-adaptor.pdf filter_i > terator.pdf function_input_iterator.pdf function_output_iterator.pdf index.pdf i > ndirect_iterator.pdf pointee.pdf iterator_adaptor.pdf iterator_facade.pdf new-it > er-concepts.pdf permutation_iterator.pdf reverse_iterator.pdf transform_iterator > .pdf zip_iterator.pdf iterator_archetypes.pdf iterator_concepts.pdf iterator_tra > its.pdf' returned 2 Is this process only successful under Linux ? I have a 'make' as the GnuWin32 package installed on Windows. But something is missing in this process.

8 24

[vmd] Adding to boost master branch
by Edward Diener 26 Aug '15

26 Aug '15

In an effort to get vmd as a submodule of the boost superproject master branch I submitted a PR against Boost on master ( https://github.com/boostorg/boost/pull/93 ). In this PR I added vmd to .gitmodules and also to the status/jamfile.v2 for testing. But looking at the Travis CI build of this a failure occurs: 0.01s$ cd status The command "cd status" exited with 0. 2.13s$ ../b2 -n -d0 error: Unable to find file or target named error: '../libs/vmd/test/' error: referred to from project at error: '.' There is most definitely a jamfile and tests at libs/vmd/test on the master branch. Is there something else I have to do to get vmd added to the master branch ?

3 5

Re: [boost] [Boost-users] [afio] Formal review of Boost.AFIO
by Niall Douglas 25 Aug '15

25 Aug '15

On 25 Aug 2015 at 12:30, Robert Ramey wrote: > > There is precedent for this: Boost.Fiber was provisionally approved > > here as a C++ 98 library with condition of a mini-review before > > entry. Boost.Fiber is now a C++ 14 library and sufficiently different > > from the library originally reviewed it may require a second > > mini-review if during its first mini-review it is felt still lacking. > > This is a precedent - a bad one which I hope to avoid a repetition of in > the future. A library which is accepted should be close enough to it's > final state so that it can be finished up on the order of a couple of > months and will result in a final version which is close to what > reviewers actually reviewed. > > We can't have a library pass a review, then have the package morph into > something significantly different then have it accepted. This make the > original review a farce. I've been watching Fiber closely since we reviewed it. As far as I know, the public API has barely changed. The documentation has improved in all the areas the review recommended. Just because the internal implementation is radically different does not mean it has morphed into something significantly different. For example, Oliver is considering making boost::fiber::future<> based on my Monad/Outcome Concurrency TS custom future framework as why bother duplicating the work. If he did, even then the public API reviewed and accepted into Boost remains exactly that which was reviewed and accepted. You don't really need to know or think about Monad/Outcome for boost::fiber::future<> to work as a C++ 11 type future. > All > > these changes to AFIO are almost entirely driven by changes since > > 2012 to the various WG21 technical standards. If they hadn't changed > > and C++ compilers (specifically MSVC) hadn't changed, AFIO wouldn't > > have changed. > > > It's very similar for Fiber, which had to be refactored > > in the face of substantial changes in C++ 14. > > I seriously doubt that a package which compiles and passes tests and > reviews with C++03 cannot do these things when C++11 comes out. What > really happens is that the author sees opportunities with C++11 that he > didn't have before then starts incorporating them after the original > review. I guess this would be called feature creep or implementation > creep. In any case, it indicates that the original acceptance was > premature. I think he saw a chance to make his internal implementation code vastly simpler and easier to maintain yes. Same as me. We're going to be supporting this thing for a decade or so, it makes sense to invest in saving ourselves work. > Ultimately it hinges on what "acceptance into Boost" means. To me it's > a library ready - with a few straight forward / uncontroversial changes > which is ready to be incorporated into the boost distribution. It's not > acceptance of an idea for a library, a prototype for a library, or that > a developer is certified to add a library in the future. I agree. But I draw the line between API and design and then the internal implementation. If it's just the latter which has changed and the API and design is identical, I think a mini-review is enough. Niall -- ned Productions Limited Consulting http://www.nedproductions.biz/ http://ie.linkedin.com/in/nialldouglas/

1 0

boost.test documentation header
by Raffi Enficiaud 25 Aug '15

25 Aug '15

Hi, Boost.test 1.59 documentation header is not the same as the other boost libraries. In particular, the green header is missing: http://www.boost.org/doc/libs/1_59_0/libs/test/doc/html/index.html vs for instance: http://www.boost.org/doc/libs/1_59_0/libs/assert/assert.html I would like to know how to include this header and what I am missing in the documentation generation. Those headers are also mentioning the latest available version of the doc. Thanks, Raffi PS.: sorry for cross-posting, but I cannot get an answer on boost-doc ML/

3 4

Boost Social Event at CppCon
by Jon Kalb 25 Aug '15

25 Aug '15

Boosters, Because a lot of Boosters are going to be attending CppCon, we¹d like to arrange a social event for Boosters/C++Now regulars. http://cppcon.org/ If you are planning to attend CppCon or even If you are just going to be in or around Bellevue, Washington between September 20th and 25 and you¹d like to join us for dinner, please let us know so we can get a count. Please send mail to: social(a)boost.org Once we settle on a date, etc, we¹ll let everyone who responded know when and where, so please let us know, even if you are a ³maybe.² I hope to see you at CppCon. Jon

1 0

Re: [boost] [Boost-users] [afio] Formal review of Boost.AFIO
by Niall Douglas 25 Aug '15

25 Aug '15

On 25 Aug 2015 at 12:37, Paul A. Bristow wrote: > 1. Should Boost.AFIO be accepted into Boost? Please state all > conditions for acceptance explicity. > > Provisionally, yes. > > Requirements: > > . Major restructuring of documentation. (Not re-writing!) > > . Completion of Boost.Was_Called_Monad and APBind. > > . Creation of a TODO list. > > . Mini-review before going into a release (perhaps of all together?). > > . More documentation of examples to explain what they demonstrate. Thanks for the review Paul. I pretty much agree with all of it. This review process has been particularly useful for helping me see the documentation as others see it - I had no idea it was so confusing! - and I'm going to try raising with the Standard C++ Foundation in Seattle next month the idea of them funding professional copy writers to take passes at C++ library documentation. Niall -- ned Productions Limited Consulting http://www.nedproductions.biz/ http://ie.linkedin.com/in/nialldouglas/

1 0

Did Boost 1.59.0 change the meaning of "using python : 3.4 : ..." in user-config.jam?
by Jonathan Wakely 24 Aug '15

24 Aug '15

Hi, I'm trying to update the Fedora rawhide package to Boost 1.59.0 and the build fails with the output below (ignore the MPI warnings). We build with the following in user-config.jam: # This _adds_ extra python version. It doesn't replace whatever # python 2.X is default on the system. using python : 3.4 : /usr/bin/python3 : /usr/include/python3.4m : : : : m ; Is that comment no longer true? Did something change in Boost 1.59.0 so that that line now sets the only allowed python version? I can make the build work with the following but I'd like to understand the change: using python : 2.7 : /usr/bin/python2 : /usr/include/python2.7 : : : : ; using python : 3.4 : /usr/bin/python3 : /usr/include/python3.4m : : : : m ; Build failure: + echo ============================= build serial ================== + ./b2 -d+2 -q -j4 --without-mpi --without-graph_parallel --build-dir=serial variant=release threading=multi debug-symbols=on pch=off python=2.7 stage MPI auto-detection failed: unknown wrapper compiler mpic++ Please report this error to the Boost mailing list: http://www.boost.org You will need to manually configure MPI support. /builddir/build/BUILD/boost_1_59_0/tools/build/src/build/feature.jam:494: in feature.validate-value-string from module feature error: "2.7" is not a known value of feature <python> error: legal values: "3.4" /builddir/build/BUILD/boost_1_59_0/tools/build/src/build/property.jam:276: in validate1 from module property /builddir/build/BUILD/boost_1_59_0/tools/build/src/build/property.jam:302: in property.validate from module property /builddir/build/BUILD/boost_1_59_0/tools/build/src/build/build-request.jam:216: in convert-command-line-element from module build-request /builddir/build/BUILD/boost_1_59_0/tools/build/src/build/build-request.jam:154: in build-request.from-command-line from module build-request /builddir/build/BUILD/boost_1_59_0/tools/build/src/build-system.jam:583: in load from module build-system /builddir/build/BUILD/boost_1_59_0/tools/build/src/kernel/modules.jam:295: in import from module modules /builddir/build/BUILD/boost_1_59_0/tools/build/src/kernel/bootstrap.jam:139: in boost-build from module /builddir/build/BUILD/boost_1_59_0/boost-build.jam:17: in module scope from module

2 8

Unicode characters in filenames
by Tom Kent 24 Aug '15

24 Aug '15

Recently there was a thread that ended up changing the boost guidelines so that Unicode characters are now allowed in C++ source files. http://lists.boost.org/Archives/boost/2015/06/223822.php However, in the 1.59 release, there was a filename that had unicode characters in it: libs\preprocessor\doc\Appendix A An Introduction to Preprocessor Metaprogramming.html. Which, HTML encoded, actually looks like: Appendix%20A%20%C2%A0%20An%20Introduction. Note the %C2%A0 character (Hex C2A0, Octal: 302240, Windows displays: ┬á)? Since this seems like a mistake, I've created a pull request for this in pre-processor. However, it begs the question: Should we support unicode codepoints for filenames in the boost distribution? I would like for this answer to be 'no' as there are still lots of tools out there that don't correctly handle unicode filenames. However, it is worth bringing up the discussion. Is there a reason we would want unicode file names? I would guess that tests uses them (especially the filesystem tests), however I would also expect that these tests generate the files on the fly, and that they aren't part of what is distributed. Thoughts? Tom Kent

5 9

"Simple C++11 metaprogramming"
by Peter Dimov 22 Aug '15

22 Aug '15

I've recently made the mistake to reread Eric Niebler's excellent "Tiny Metaprogramming Library" article http://ericniebler.com/2014/11/13/tiny-metaprogramming-library/ which of course prompted me to try to experiment with my own tiny metaprogramming library and to see how I'd go about implementing tuple_cat (a challenge Eric gives.) Ordinarily, any such experiments of mine leave no trace once I abandon them and move on, but this time I decided to at least write an article about the result, so here it is, with the hope someone might find it useful. :-) http://pdimov.com/cpp2/simple_cxx11_metaprogramming.html

17 55

cache size runtime detection
by Joel FALCOU 22 Aug '15

22 Aug '15

We have a bunch of cross-platform CPU cache size and cache line size detection that we want to offload into boost in preparation for the first reviewable version of Boost.SIMD. It's rather smallish in term of API but the code is non-trivial. I think it's a bit broad to be in utility/core, doesn't really fit in align and IIRC there is no "general memory related" library in Boost. Questions: 1/ would there be interest to have such utility in Boost ? 2/ here should we put it ? Is Boost.Memory a viable solution or could it be hosted somewhere non-trivial ? Regards

10 25

[Polygon] trait register on derived class
by Lechuan Xue 21 Aug '15

21 Aug '15

Hi, Currently, if I have one custom geometry and a few further derived custom geometries, I need to do trait register on all of them. Like: class derived_point1 : public base_point {}; class derived_point2 : public base_point1 {}; namespace boost { namespace polygon { struct geometry_concept<base_point> { typedef point_concept type; }; struct geometry_concept<derived_point1> { typedef point_concept type; }; struct geometry_concept<derived_point2> { typedef point_concept type; }; } What I want is to register all custom geometries in one step. Like: template<typename T> struct geometry_concept<T, typename std::enable_if<std::is_base_of<base_point, T>()>::type> { typedef point_concept type; }; To do that, I need to add a dummy template type to all the trait classes to enable SFINAE. Attached is the patch (based on boost 1.57.0_1). Is this something we can consider? Thanks, Leo Xue

1 0

Transfer ownership of DLL into boostorg
by Antony Polukhin 19 Aug '15

19 Aug '15

Hi, I'd like to transfer Boost.DLL library ( https://github.com/apolukhin/Boost.DLL) into the boostorg. What's the current procedure for that? -- Best regards, Antony Polukhin

3 6

[http] Boost.Http formal review is finished
by Bjorn Reese 19 Aug '15

19 Aug '15

The formal review of Boost.Http is finished, and I would like to thank all who participated. The following reviews have been recorded: - Antony Polukhin: No - Darren Cook: No - David Sankel: No - Lee Clagett: No - Niall Douglas: Yes, conditionally - Roland Bock: No - Tom Kent: No Please let me know if I have missed any. The final review results will be posted later.

5 8

[core] Determining interest for two new classes: readonly and newtype
by Sam Kellett 19 Aug '15

19 Aug '15

Hey, I have two classes I've developed that have been used in my own projects that I think could have a place in Boost. They are outlined below. readonly<T>: This is a wrapper class for a type to replace a const-type field in a movable class. It has const access to the type so can't modify except for the move constructor and move assignment operator. This solves the problem that no fields in a movable class can be const which can cloud the intentions of a field. readonly copies the accessor patterns seen in classes such as optional and the smart pointer collection. Example: struct foo { foo() : str("hello world") {} readonly<std::string> str; }; foo f; auto g = std::move(f); static_assert(std::is_move_constructible<foo>{}, ""); std::cout << *g.str << std::endl; g.str->clear() // error: non-const method. ----- newtype<N, T> This is shamelessly ripped off from Haskell and provides strongly-typed typedefs to C++. It actually has two template parameters, one is an incomplete type that provides a unique identifier for this typedef. I've opted to use the name of the typedef with an '_t' suffix, the second is the raw type that it contains. Like readonly the underlying type can be accessed by operator*, operator-> and get() methods. Example: using age = newtype<struct age_t, int>; age a{25}; using byte = newtype<struct byte_t, int>; byte b{42}; // do something with bytes (*not* any old int). void bar(const byte); bar(a); // error: wrong type wanted 'byte' got 'age' bar(b); // okay bar(89); // error: wrong type wanted 'byte' got 'int' assert(*b == 42); Any thoughts on the design and/or their place in Boost would be much appreciated. Cheers, Sam

8 16

[build] Algorithm for setting PATH when a 'run' or 'run-fail'
by Edward Diener 18 Aug '15

18 Aug '15

What is the algorithm for setting a PATH on Windows when the 'run' or 'run-fail' rule occurs in a jamfile ? In running clang on Windows when an executable is created the PATH needs to start with the bin directory of the mingw(-64)/gcc implementation that a particular version of clang uses as its RTL when the program is compiled/linked. It appears that when the 'run' or 'run-test' rule occurs with the clang toolset on Windows that the PATH is adjusted to have the directory of the clang++ executable and not that of the corresponding mingw(-64)/gcc RTL ? Is there any solution to this from within Boost Build ?

2 5

[lclcontext] Any interest in Pythonesque "with-as" statement in C++.
by Mostafa 18 Aug '15

18 Aug '15

I think Python's concept of Context and Context Managers useful and I've adapted, to the best of my abilities, a similar concept in C++. For those not familiar with this concept, I'll quote a brief snippet from the documentation: "Simply stated, this library enables the use of the Pythonesque with-statement construct in C++. More broadly, this library seeks to formalize a generalized version of a subset of the RAII (Resource Acquisition is Initialization) idiom that, for the lack of preexisting terms, I shall refer here to as the STEP (Scope Triggered Event Processing) idiom. The STEP idiom is the commonly occurring use case where for a given block of code some user specified action(s) must execute on entry and on exit, and the failure to do so will result in some deterministic behavior." You can find the library here: https://github.com/m-w-a/WG Documentation is here: https://github.com/m-w-a/WG/tree/master/Local/Docs (In the same repository I've also redid Boost's local_function, but that the subject of another posting.) If there is enough interest from the community for such a library then I will go ahead and "Boostify" it.

3 6

[http] Formal Review
by David Sankel 17 Aug '15

17 Aug '15

> 1. Should Boost.Http be accepted into Boost? Please state all conditions for acceptance explicity. No. This library unfortunately is not complete enough to be in Boost. > 2. What is your evaluation of the design? >From my reading, the design of the low level components that are in the library seems okay. > 3. What is your evaluation of the implementation? Looks okay from what I've seen. > 4. What is your evaluation of the documentation? More tutorials for common use cases are needed. I fear, though, that the only use case of these low-level components is the writing of a higher-level one on top of it that is more widely useful. > 5. What is your evaluation of the potential usefulness of the library? In its current state, I do not find this library very useful. A Boost HTTP library should support both client side and server side. Micro-services are quite commonly used these days and only communicating one direction excludes this library from having full participation. While I very much enjoy and appreciate the exposed lower-level functionality, higher level abstractions are required to scratch the itch most developers have when they want a C++ HTTP library. I could not recommend this library over pion for this reason even though I like this library's design better. In particular, we need really good stories for: a) How to fetch the contents of a website given a URL. b) How to make a static page server. c) How to write code that handles a POST or GET request dynamically based on specified parameters. d) How to write a server that accepts file uploads. e) HTTP/2.0 f) Websockets I would also like to see instances of this library being used in production. That would give some evidence that the design works in practice. There is the argument that we should accept this into Boost now because, once it has more features, it'll be really great. I think that Boost is for libraries that are already really great. I don't see how getting more exposure to an incomplete library helps either Boost or the library, but I do see how it can do damage to the Boost name. > 6. Did you try to use the library? With what compiler? Did you have any problems? I built the library and ran the single example. I used gcc 5.2.0. I didn't run into any problems and was quite happy with this part of the review. > 7. How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? I spent a couple hours reading through the documentation and the mailing list discussions. > 8. Are you knowledgeable about the problem domain? Yes. I'm the architect of a large C++-based web framework for the US Government. We currently use pion as our primary server and client low-level library. I've contributed some minor patches to pion. -- David Sankel

1 0

[lclfunction][local_function] Any interest in a redone version of local_function.
by Mostafa 17 Aug '15

17 Aug '15

I've made a library called lclfunction which is basically a redone version of local_function except for the following important differences: 1. This library allows the function name to be specified at and only at the top of the local function declaration. 2. This library allows local functions to maintain internal state without referencing external variables (via varset). 3. This library allows the use of globally scoped types as macro parameters, i.e., ::std::pair<..., ...>. 4. This library can handle binding array types. 5. IMHO, this library has a cleaner implementation: a) The preprocessor translator is partitioned into a front end and back end. b) A well-defined symbol table bridges the two translation layers. c) It has well-defined error-generating mechanism with a separate error pass before code generation. 6. It uses a different syntax. The main reason I did this redone library is because local_function required putting the function's name in the closing macro and that rubbed me the wrong way, my view is that it should and can be placed in the opening macro. If there is enough interest from the community I will "Boostify" it. Thanks, Mostafa

1 1

boost.org https certificate expired 4 month ago
by Jens Weller 16 Aug '15

16 Aug '15

Hello boost community, I noticed today that the https of boost.org is expired, and should have a new certificate: https://www.ssllabs.com/ssltest/analyze.html?d=boost.org thanks, Jens Weller

11 17

[http] Formal Review
by Antony Polukhin 16 Aug '15

16 Aug '15

Hi, This is my formal review for Boost.HTTP library. 1. Should Boost.Http be accepted into Boost? No. It has some big architectural issues and a lot of issues in code. 2. What is your evaluation of the design? That's the fatal problem of the library. It seems like the library attempts to get best from ASIO and cpp-netlib and unfortunately fails. Now let's get into details: * ASIO is a low level abstraction over protocol that does not take care about memory management of buffers (in most cases it's the responsibility of user to allocate and keep alive the required buffers). * cpp-netlib takes care of memory management, hides low-level stuff. Boost.Http is stuck somewhere in the middle: sometimes it allocates and extends buffers, sometimes not. Because of that the design does not seem solid. Any attempt to hide all the memory management inside the library will end in an another implementation of cpp-netlib. So it seems right to remove all the memory management from the library internals and make the library closer to ASIO. Here are my recommendations for separation of flies and dishes: * Stick to the idea that http socket must ONLY manage connection without extending the ASIO's send/receive function signatures. That means that http1.0 and http1.1 sockets must be almost a typedef for tcp/ssl socket. Http2.0 socket must be very close to SSL socket. No additional methods (like async_read_trailers or async_write_response) must be provided. * It must be a user's responsibility to provide buffers for messages. Never extend buffers in socket-related methods. * Provide helper classes that parse and generate http * Provide out-of-the-box completion conditions for async_read operation: http::completions::full, http::completions::headers, http::completions::body... Those bullets will allow to write following code (based on http://www.boost.org/doc/libs/1_58_0/doc/html/boost_asio/tutorial/tutdaytim… with minimal modifications): #include <ctime> #include <iostream> #include <string> #include <boost/bind.hpp> #include <boost/shared_ptr.hpp> #include <boost/enable_shared_from_this.hpp> #include <boost/asio.hpp> std::string make_daytime_string() { using namespace std; // For time_t, time and ctime; time_t now = time(0); return ctime(&now); } class http_connection : public boost::enable_shared_from_this<http_connection> { public: typedef boost::shared_ptr<http_connection> pointer; static pointer create(boost::asio::io_service& io_service) { return pointer(new http_connection(io_service)); } http::socket& socket() { return socket_; } void start() { message_.resize(4 * 1024); boost::asio::async_read(socket_, boost::asio::buffer(message_), http::completions::full(message_), // read until all the whole request is in `message_` boost::bind(&http_connection::handle_read, shared_from_this(), boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred)); } private: http_connection(boost::asio::io_service& io_service) : socket_(io_service) {} void handle_write(const boost::system::error_code& /*error*/, size_t /*bytes_transferred*/) {} void handle_read(const boost::system::error_code& error, size_t bytes_transferred) { assert(!error); // for shortness // `message_` contains the whole request, including headers and body // because http::completions::full was provided { boost::system::error_code e; http::view v(message_, e); // represent buffer as http message assert(!e); // no error occured during parsing assert(v.read_state() == http::read_state::empty); std::cerr << v.version(); // "HTTP1.1" std::cerr << v["Content-type"]; // "plain/text" std::cerr << v.body(); // string_ref("Hello! This is a body content. What time is it?") message_.clear(); // `v` is now invalid to use! } { http::generator resp(message_); // use `message_` for an output resp << make_daytime_string(); // append daytime to body resp["Content-Type"] = "plain/text"; // set some headers resp.version(http::version::HTTP_1_1); // explicitly set HTTP version resp.code(200); // "200 OK" resp.flush(); // explicitly flush to buffer. Done automatically in destructor } boost::asio::async_write(socket_, boost::asio::buffer(message_), boost::bind(&http_connection::handle_write, shared_from_this(), boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred)); } http::socket socket_; // manages the connection only std::string message_; }; class http_server { public: http_server(boost::asio::io_service& io_service) : acceptor_(io_service, http::endpoint(http::all_versions, tcp::v4(), 80)) { start_accept(); } private: void start_accept() { http_connection::pointer new_connection = http_connection::create(acceptor_.get_io_service()); acceptor_.async_accept(new_connection->socket(), boost::bind(&http_server::handle_accept, this, new_connection, boost::asio::placeholders::error)); } void handle_accept(http_connection::pointer new_connection, const boost::system::error_code& error) { if (!error) { if (new_connection->socket().version() == http::version::HTTP_2_0) { // do some more stuff } new_connection->start(); } start_accept(); } http::acceptor acceptor_; }; int main() { try { boost::asio::io_service io_service; http_server server(io_service); io_service.run(); } catch (std::exception& e) { std::cerr << e.what() << std::endl; } return 0; } This will also untie Boost.HTTP from ASIO. Now users could use http::generator/http::view to read/generate HTTP data. This significantly extends the use cases of your library (for example on a previous work we had our own network transfer implementation, but we'd gladly use a http parser and generator). Such code is also less intrusive: only minimal chages were required to change a tcp example into the http example. Users will appreciate that, especially in cases when ASIO is already used for HTTP. BTW, after that you could easily implement http::stream (that must be close to tcp::stream by functionality). http::stream would be a killer feature that would be widely used by utility programs (as I remember current Boost's regression testing requires it, but uses tcp::stream with a bunch of workarounds). Please, implement the HTTP2.0 protocol. There are some open source solutions that are licensed under the Boost license and are very close to full implementation of HTTP2.0. Just reuse the code and chat with the authors for better understanding of the problems. 3. What is your evaluation of the implementation? Not perfect. For example https://github.com/BoostGSoC14/boost.http/blob/master/include/boost/http/so… It seems that `std::vector<asio::const_buffer> buffers; buffers.reserve(nbuffer_pieces);` is meant to be here. There are more such places... It seems that some useful features (like custom allocators) are not supported by the library. It's better to be fixed. Some of the implementation issues are because of the library design. For example requesting multiple async operations (async_read_request+async_read_some+async_read_trailers) is performance hit. It's better to read all the data at once (just like in the example from above). 4. What is your evaluation of the documentation? First code snippet in tutorial contains mostly ASIO's stuff and almost no HTTP stuff. That's wired... If bullets from above would be implemented, then I'd rather start with parsing and generating simple http messages. Then an example with sockets could be provided. Also please do not use coroutines at least in first example. coroutines is a new feature in ASIO, many users use old Boost versions that have no coroutines and some users are not familiar with them. So if you start with coroutines user will have to go to ASIO docs and dig into coroutines to understand the very first example. Example without coroutines will be more user friendly. 5. What is your evaluation of the potential usefulness of the library? Library is very useful and required. But in current state it must not be accepted into Boost. 6. Did you try to use the library? With what compiler? Did you have any problems? Have not tryed. 7. How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? A few hours digging into docs, about 3 hours looking into the sources, about 3 hours formulising the issues and recommending solutions. 8. Are you knowledgeable about the problem domain? Not an expert, but used ASIO a lot along with cpp-netlib and some other libraries close to the proposed one. 8.3333(3) Review Please, reserve a bigger window when such complex library is proposed for review. It's hard to review it in 10 days. 8.6666(6) For Reviewers I urge other reviewers to take a look at the cpp-netlib. If you treat Boost.Http as an out-of-box solution, then cpp-netlib is more mature, user-friendly and solid. If you treat Boost.Http as a basic building block for HTTP (just like ASIO is a basic building block for networking), then it's better to stick to the ASIO's design and do not *partially* manage memory! P.S.: I hope that this library would be changed according to my recommendations and submitted for a new review. -- Best regards, Antony Polukhin

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Re: [boost] [asio-users] [http] Formal review of Boost.Http
by Niall Douglas 16 Aug '15

16 Aug '15

On 7 Aug 2015 at 19:29, Vinícius dos Santos Oliveira wrote: > > I do not believe Http is ready for peer review for these reasons, and > > I personally would urge you withdraw it until you have fixed these > > issues and then come back to us. If you do not withdraw it, I will > > vote for rejection. > > Can I persuade you to review the Boost.Http design? I'd reject myself if > you find any fundamental flaw on the design and even if you're going to > reject the library because the lack of tooling (not directly related to > design or documentation, which are the most important items on any > library), it'd be useful to know what needs to be addressed on the design > before I submit again (in the case the submission is rejected). I think my earlier email was poorly phrased now I've slept on it. I made my objections seem like they were about portability, when they were really about design and intent of Http. What I should have said was this: Standalone ASIO is the reference Networking TS implementation for standardisation. Http is currently a set of extensions to Boost.ASIO specifically when it *should* be a set of extensions to the reference Networking TS implementation for C++ standardisation. This is why your current design and architecture is flawed, but luckily there isn't too much work to fix this by finishing the port of Http to the Networking TS. The Internet of Things tends to involve lots of small somewhat underpowered internet devices where C++ is likely going to play a much more important role than historically in embedded systems. The chances are that any Networking TS in C++ will be very extensively used in such IoT applications. If there were also a high quality set of extensions adding HTTP support to the Networking TS, I think your chances are good that your Http library would be seriously considered by WG21 for standardisation. *This* is why I very strongly believe that Http needs to cleave itself tightly to the Networking TS reference implementation, and not to Boost.ASIO. Moreover, if you make Http an extension of the Networking TS, you get Boost support with that for free - Http becomes dual use. > About C++03 support, it's not required for Boost acceptance, so I can add > later. I want to increase tests coverage a lot before porting code to > C++03, so I don't introduce accidental bugs in the process. As a strong advocate for C++ 11 over 03 I can understand. However, IoT developers tend to be stuck on some pretty ancient toolsets for longer than others. 03 support I think would greatly increase your potential userbase. > In the case the abstractions I need enter on the C++ standard, maybe your > APIbind will help me. I actually would advise you to choose ASIO's STL abstraction machinery over my own alternative APIBind in this instance. > But I just don't find any reference to BOOST_ASIO_HAS_STD_SYSTEM_ERROR > outside of config.hpp. Even if it was used, it is undocumented, which means > it is an implementation detail that won't be guaranteed to be there forever > (accidental behaviour versus a documented guarantee). I'm pretty sure that implementation detail won't change in a hurry. STL abstraction machinery changes as quickly as a STL does i.e. every decade or so. > > https://svn.boost.org/trac/boost/wiki/BestPracticeHandbook#a7.SAFETY:S > > tronglyconsideranightlyorweeklyinputfuzzautomatedtestifyourlibraryisab > > letoacceptuntrustedinput > > That's why this first implementation uses a proven-parser that is very well > tested. The buck always stops with the top most layer, not internally used third party libraries. You NEED to fuzz test untrusted inputs when parsing HTTP. For all you know, your STL implementation could be the thing with the overflow bug, or the way in which you use it. > > * I don't understand why you cannot issue more than one async read at > > a time nor async write at a time. In something like pipelined HTTP > > that seems like a very common pattern. I smell a potential design > > flaw, and while the docs mention a "queue_socket" I can't see such a > > thing in the reference section. > > > > Too much synchronization and buffering. > > The pipeline has the following requests: > > A => B => C > > If I were to allow replies to request B, the design would be more complex, > increasing the difficult to implement alternative backends and everyone's > life. Also, the reply to request B cannot actually be sent while the reply > to request A is on hold. This means that the whole response to request B > would need buffering and if response B is a video live stream, this means > an implicit (the user cannot know) crash after an unfortunate memory > exhaustion. I couldn't claim a **lightweight** server if this excessive > buffering was to occur. I couldn't claim the project is appropriate for > embedded devices if I had chosen the buffering approach. It's a trade-off. > I should write about it in the "design choice" of the documentation. > > HTTP/2.0 does have proper multiplexing and it can be more useful to respond > several requests without "head of line blocking". Ok, let's accept that HTTP before 2.0 can't multiplex (not my experience personally, but I agree it's got big gotchas before 2.0). You need a user facing API for Http which lets user code multiplex where that is available, and not multiplex when that is not available. In other words, identical code written against Http must automatically be optimal in either connection case. You're probably going to ask how I might implement that right? I think my first guess is you need two completion handler layers and therefore two completion dispatcher reactors: the bottom layer is the same as ASIO's and uses the ASIO reactor, whilst the top layer which users of Http sees is a reactor operated by Http and is disconnected, though operated by, the ASIO reactor. > A queue socket is a concept, I don't provide one. I can look into how make > the documentation less confusing by adding a page exclusively dedicated to > explain the problem it solves. Would that work for you? It could be this queue socket concept of yours is exactly what I just proposed as two completion handler and reactor layers. In either case, I don't think queue sockets should be a concept, I think they need to be the core of your library's user facing API. If power users wish to bypass that user facing API layer for less hand holding and less latency, that should also be possible. But I think HTTP multiplexing should be assumed to be the default starting point for Http applications. Once HTTP 2.0 is more common, it will seem madness that Http's user facing API is _not_ 100% multiplexing. > * Your tutorial examples use "using namespace std;" at global level. > > That's a showstopper of bad practice, and you need to purge all of > > those. Same for "using namespace boost;" at global level. > > > > The tutorials should be as small as possible to not scary the users. > > But I can put a comment "you should avoid using namespace". Does it help? using namespace is fine at local scope. It's not fine at global scope. Replacing all global using namespace with local using namespace is all you need to do. > * Your reference section is one very long thin list. You might want > > to use more horizontal space. > > > > I'd be happy already if I knew hot to remove the TOC from the reference > page. It'd be much more clean already. Personally in AFIO I hack the CSS to make the list into columns. ASIO employs a table. There are many solutions. > * I personally found the design rationale not useful. I specifically > > want to know: > > > > 1. Why did Http choose ASIO as my base over leading competitor X > > and Y? > > 2. What sacrifices occurred due to that choice? i.e. things I'd > > love weren't the case. > > > > I assume I don't need to reply these questions during the review, given the > reviewers may already be experienced on the answers. Well ... I'm not sure that's actually the case. It's not we don't have opinions on the answers, it's whether our answers are different to your answers. You'll see this during the AFIO review later this month - I have some really weird opinions no one else shares like choosing my own custom lightweight monadic future-promise implementation over async_result. That will be the source of much criticism I'm sure. > 3. What alternatives may be better suited for the user examining > > Http for suitability and why? i.e. make your documentation useful to > > people with a problem to solve, not just a howto manual. > > > > I don't quite understand this point. What I'm really asking is for details of when before starting Http you reviewed the options available and the designs they used, and exactly why you chose the design choices in Http you did with reference and comparision to prior art. Like a literature review, but for programming libraries. Does this make sense? It's partially for us to help us understand your choices, but also to help those examining Http to see if it's useful to them to figure out the best solution to their problem (which may be to use an alternative to Http). Documentation which is useful over documentation which is reference. > * Benchmarks, especially latency ones which are important for many > > uses of HTTP are missing. I'd particularly like to know confidence > > intervals on the statistical distribution so I know worst case > > outcomes. > > > > These values will change when I replace the parser used now. Also, they can > change based on the buffer sizes and parser options, which the user is/will > be able to change. > > Nevertheless, I do want to do some serious benchmarking, specially because > it'll give me a reference point when I write my own parser and want to > compare performance speedup. I can do some poor benchmark this weekend and > show the results. That would be interesting, but don't go crazy on it. Also, please do enable the undefined behaviour sanitiser permanently including in release mode and with full stack smashing protection before running benchmarks. Anything parsing malicious input should have all those turned on where available. > I hope all the above isn't too disheartening Vinícius. > > Not at all. I think you're the second person to dedicate more time > reviewing my work and this isn't disheartening at all. Just that your > feedback is usually around tooling and not the design itself (everybody has > its preferences). That's because I like the design a lot and have little bad to say about it. I've also been subscribed to your github since the beginning, and I have been reviewing your code on and off as you wrote it. You're a talented programmer. > > Jamfile for the main library build, > > Consider this done. I won't integrate into Boost without removing CMake > first. This was already partially stated in the Bjorn's announcement (but > somehow implicit, to be fair). I have no problem at all with dual build systems if you're happy keeping both maintained. Niall -- ned Productions Limited Consulting http://www.nedproductions.biz/ http://ie.linkedin.com/in/nialldouglas/

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Re: [boost] [asio-users] [http] Formal review of Boost.Http
by Niall Douglas 15 Aug '15

15 Aug '15

On 13 Aug 2015 at 8:58, Vinícius dos Santos Oliveira wrote: > First of all, sorry to all members of the list about my unavailability. I > was planing to write an experimental HTTP 2.0 backend, so I could give more > confidence about how much I believe this Boost.Http core I present for > review is the right abstraction. > > Anyway, looks like I took the wrong approach. I should have answered the > easiest questions first and implement the HTTP 2.0 backend (experimental, > using existing-library and not Boost-quality) later. That's a wise move Vinícius I think. > > Where I'm really at is I think if Http is accepted you're going to > > either have to ditch it and reimplement atop the Networking TS as > > Chris folds the substantial changes WG21 will force onto ASIO into > > Boost.ASIO, or end up refactoring Http to cleave more closely to the > > Networking TS anyway. > > I'm okay with that. You may be, but I would worry about your users. Boost users expect stability and permanence. > > I think for the majority of HTTP users they just want it to work > > without surprises to a high default performance level. If you look at > > the history of the HTTP library support in Python you'll see what I > > mean - firstly, it's surprisingly easy to get a HTTP library API > > design wrong, even in a v2 refactor. And secondly that people need > > both a stupid-simple API and a more bare metal API *simultaneously* > > with HTTP, and therein lies the design gotcha. > > > > If you want a high level API, you're going to use coroutines. There is > nothing in the wild so readable as coroutines. Coroutines are **the** > solution to solve spaghetti code in asynchronous abstractions. Lambdas and > futures will never be as readable as coroutines. Anyway... God no. I would see a top level API as being synchronous, so something like python's urllib3: import requests r = requests.get('http://www.boost.org') print(r.json()) It may coroutinise but still appear to be synchronous, but that's a separate moving ball and not one Http can tackle alone. > The more I think, the more I believe how much such "middle-level" API is > underestimated. > [snip] > It's not really like Boost.Http is too low level. It's more like only the > less polemic building blocks are available now. You'll see the same main > players in a higher-level abstraction and the main difference is most > likely that you won't manage the main players yourself. Think of it as a Boost user. The average Boost user is going to see Boost.Http and think to themselves, "oh goody I can now write: import requests r = requests.get('http://www.boost.org') print(r.json()) ... in C++ and yay I've just chopped 10,000 lines of buggy hack code from my codebase." And that's exactly what I would expect too from a library called Boost.Http. What you're providing isn't that though: it's a set of low level HTTP related extensions to Boost.ASIO. From my review of your code and docs, and what you've told me, I think the ideal location for your library is within ASIO under the asio::http namespace. However, assuming Chris isn't keen to allow that as a git submodule within ASIO (he might be, I don't know), I think as a very minimum you need a name for your library which says it is a set of low level HTTP related primitives for Boost.ASIO. That name is not Boost.Http for sure. A later library you might submit could be called Boost.Http, but it would provide a daft easy API like the above for Python's urllib3. In fact, if you can achieve a more appropriate name choice, I'll change my vote from rejection to a conditional acceptance as you've done a great job in persuading me from where I was. You've impressed with me your awareness of the tradeoffs involved in a moving API environment, and though I severely personally disagree with your choice of Boost.ASIO over ASIO, I can also see that targeting a more stable API in the form of Boost.ASIO for now makes sense. How does that sound? Niall -- ned Productions Limited Consulting http://www.nedproductions.biz/ http://ie.linkedin.com/in/nialldouglas/

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Making the Windows binaries 'official'
by Tom Kent 15 Aug '15

15 Aug '15

<history> After the boostpro.com organization dissolved, there was never an official place to go to get pre-built binaries for the releases. Some random components were made available on the sourceforge download page and I had been hosting them on my own website (http://boost.teeks99.com) since I started building them around the release of 1.37. A couple years ago, before the release of 1.54, I asked the community if they would like my builds to be hosted on the sourceforge site, and the answer was positive: http://lists.boost.org/Archives/boost/2013/04/202460.php Since the 1.54 release, I've generally been uploading the windows binaries based on the RCs and enabling the downloads just a few minutes after the release notice goes out. </history> I would now like to propose that we make these libraries an official part of each Boost release. I don't think this entails much, just the following: 1) Have the release team coordinate with me to ensure that the binaries are ready before announcing the release. 2) Include a link to them in the release announcement. 3) Link to them from the website. It would also be good to get others who can run the scripts to perform the build, if I am someday unable to do this. The biggest hurdle here is having a (virtual) machine with all six versions of visual studio on it. Is this something the community would be in favor of? I know that many of the people on these lists don't use windows and if they do are generally capable of building the windows binaries themselves, however there is a large group out there that prefers to just get the installer for them (like they do for other projects like Qt, wxWidgets, etc). Thoughts? Tom Kent

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[job] exec job-graphs in a NUMA env (was a thread pool that allows recursive calls)
by Oliver Kowalke 15 Aug '15

15 Aug '15

This library is related to the posting 'a thread pool that allows recursive calls' (http://lists.boost.org/Archives/boost/2015/06/223426.php) e.g. the library solves the many-dependent-jobs problem. boost.job is a derivative work of boost.task (which was published in 2008, the code is refactored and now split into boost.context, boost.coroutine2/boost.fiber and boost.job). boost.job provides a framework for asynchronous execution of job-graphs (a job is a small unit of code that can be executed independently and parallel, e.g. it's a fain-grained work item) of arbitrary dependency, e.g. solving the many-dependent-jobs problem (M: worker threads, N: jobs waiting for other jobs; M << N). Each (logical) processor of a dedicated processor set (configurable) gets a worker-thread assigned. Each worker-thread runs a fiber-pool (launch policy is customizable). A submitted job is always executed by a worker-fiber. While using boost.fiber jobs are scheduled cooperatively so that a job can yield to other jobs during its execution. Jobs can be synchronized via primitives like mutex's, conditions, barriers and channels (message exchange) from boost.fiber without blocking the worker-thread. Fibers provide a fast context switch. boost.job supports to inspect the NUMA topology (e.g. which logical processors are online, and which processors share L1/L2/L3 cache). This information can be used to select a appropriate processor for a job. For a fast access to job related data, boost.job provides functions and classes to allocate memory on NUMA nodes (processors of a NUMA node share cache and have a faster access to its associated memory bank than processors of other nodes.). source: https://github.com/olk/boost-job documentation: http://olk.github.io/libs/job/doc/html/

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Re: [boost] Build Error VS14 + Intel 15.0 (Update 4, the latest)
by degski 15 Aug '15

15 Aug '15

Changing intel-win.jam, line 476 (boost 1.59.0 rc2) from: .iclvars-15.0-supported-vcs = "12.0 11.0 10.0 9.0" ; to: .iclvars-15.0-supported-vcs = "14.0 12.0 11.0 10.0 9.0" ; solves the problem.

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Master branch is open for changes
by Marshall Clow 14 Aug '15

14 Aug '15

The release has been tagged, and library maintainers are free to merge to release again. Thanks to everyone for their cooperation. -- Marshall

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Boost 1.59.0 has been released
by Marshall Clow 14 Aug '15

14 Aug '15

Release 1.59.0 of the Boost C++ Libraries is now available. These open-source libraries work well with the C++ Standard Library, and are usable across a broad spectrum of applications. The Boost license encourages both commercial and non-commercial use. This release contains two new libraries and numerous enhancements and bug fixes for existing libraries. New Libraries * Convert: An extendible and configurable type-conversion framework, from Vladimir Batov. * Coroutine2: from Oliver Kowalke For details, including download links, see http://www.boost.org/users/news/version_1.59.0 You can also download directly from SourceForge: http://sourceforge.net/projects/boost/files/boost/1.59.0/ To install this release on your system, see http://www.boost.org/doc/libs/release/more/getting_started/index.html Thanks, --The Boost release team Vladimir Prus Rene Rivera Marshall Clow Eric Niebler Daniel James Beman Dawes

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[filesystem] proposal: treat reparse files as regular files
by Paul Harris 14 Aug '15

14 Aug '15

Hi all, -- Proposal -- tl;dr : I propose that we treat all non-symlink "reparse_files" as "regular_files". If the boost library user wants to do something special with these plain reparse files, they should use alternative means. But typically they are supposed to be treated as regular files. This means we could drop the "reparse_file" enum, or continue to use it for a special-case whats_my_real_status() function. --- Motivation --- Windows Server 2012 uses reparse points to implement deduplification. Those files should be treated as regular files in all circumstances. Currently, they are not classed as "regular" files, so fs::copy() will skip those files, and library-user code written to list files based on official examples will ignore all dedup'd files. This is causing serious and latent problems at the user end, because deduping only happens occasionally after X days, and users cannot easily check if a file is dedup'd (they look just like regular files). --- Real life example --- Another example of reparse use is the "Symantec Enterprise Vault" (version 10), which I found running on one site. It replaces files on the server with reparse-point files. FSUTIL REPARSEPOINT QUERY filename.txt shows the contents of the reparse buffer, which is a URL to an internal HTTP server. The url points to a .asp link with a bunch of codes and dates to identify the file in the server. Copy-pasting that URL into a webbrowser allows you to directly download the file via the webbrowser, which is pretty neat I suppose. In this case, the reparsed-files in Windows Explorer all have grey X crosses on their file icon. If you "type" them (via cmd) or open them, the icon loses the grey cross and the file is no longer a reparse point file. My software refused to read the files because they were "not regular files". Once I adjusted the boost code (described below), my software saw them as regular and opened the files. The file icons lost the grey cross. SO it seems that the file server automatically downloads and replaces the files with the stored content on demand, and the file reading client program should really just treat these files as normal files. --- Short logic --- reparse files (that are not symlinks) should almost always be treated as plain files. They are a mechanism for MS file servers to store files in clever ways, but the client should not care and just read/write them as if they were normal files. This is different to all the other "other" files which can't be treated like normal files: block, character, fifo, socket, unknown So, reparse files should not be grouped with the "other" file types. They are also NOT symlinks, and should not be treated as symlinks (which would require special decisions for copying, or querying the status, or checking if the target still exists). --- What are reparse files --- I did some reading, if I understand correctly: Reparse points give drivers (on the server) a chance to get data through some other specialised means (eg query from a cluster store). They are processed by the server, not the client, so clients should treat reparse data as opaque data. EXCEPT for symlink reparse files. https://msdn.microsoft.com/en-us/library/dd541667.aspx quote:"The following reparse tags, with the exception of IO_REPARSE_TAG_SYMLINK, are processed on the server and are not processed by a client after transmission over the wire. Clients should treat associated reparse data as opaque data." It seems like the rest of the tags are used for connecting files to other types of storage (eg long term storage, cluster storage). Clients may need to do something special with SOME reparse point files, IF the client cares about how long the file read may take. https://msdn.microsoft.com/en-us/library/windows/desktop/aa365505(v=vs.85).… quote: "Most applications should take special actions for files that have been moved to long-term storage, if only to notify the user that it may take a while to retrieve the file." --- Changes required --- Option 1: change is_regular_file() to return true where type==reparse_file I don't like this option, as library-users could be checking the type directly instead of using is_regular_file(). Option 2: These functions return reparse_file: fs::file_type query_file_type(const path& p, error_code* ec) file_status status(const path& p, error_code* ec) file_status symlink_status(const path& p, error_code* ec) They should instead return regular_file instead. --- How to test with dedup files --- Creating dedup'd files is a feature only available on Windows Server 2012, I believe, although Windows XP/Vista/7/8/10 clients all can read dedup files. Here is how I created a windows server to test with (for free!) on a demo Azure cloud server. I have one working, so if anyone would like to use it for their testing, let me know. Step one: follow this blog article: http://blogs.technet.com/b/tommypatterson/p/azureservertrial.aspx once the machine was "running" I clicked Connect at the bottom. That gave me an .rdp file which in theory I could use with rdesktop, but it uses a DNS name that was only just created, so that didn't work. When you click the name of the server in the list, it shows the public IP on the right.. and the port then you can do this $ rdesktop that.ip.addr:port But only if you have the latest rdesktop AND you have set up kerberos something-something. Instead I found a windows computer and used remote desktop from there. --- Once inside, in the "Server Manager --> Dashboard" window on the screen, click "Add Roles" then go next next until "Server Roles" expand "File and Storage services" , "File and iSCSI" , and tick "Data Deduplication" Then next next etc and Install. Wait a bit... and its done. http://www.techrepublic.com/blog/data-center/configuring-windows-server-8-d… --- Continuing on that webpage... Time to enable dedup. There is a temp disk D: so lets enable there. Method 1... I did this and then went to method 2... Start PowerShell, type: "Enable-DedupVolume D:" Method 2... in that same Dashboard, hit the 4th button (File and Storage Services) Then Volumes --> Disks click Volume 1 at the top, and then right click D: at the bottom --> Configure Dedup. To try and accelerate this puppy, I set the "age to dedup" to 0 days. http://www.techrepublic.com/blog/data-center/windows-server-2012-deduplicat… --- Time to make something to dedup. We'll just duplicate the warning.txt file that exists on D: In powershell: PS> D: PS> $file = Get-Content DATALOSS_WARNING_README.txt Then, do these 2 commands a bunch of times until "big.txt" gets to say 6MB PS> Add-Content big.txt $file PS> $file = Get-Content big.txt Then use windows explorer (or other) to make a dozen copies of big.txt Copy c:\windows\explorer.exe to D: to give it something to dedup Go to D: and then copy-paste explorer.exe a dozen times. In PowerShell, type: PS> Update-DedupStatus -Volume D: PS> Start-DedupStatus -Type Optimization -Volume D: and then wait for it to finish. you can track its progress with: PS> Get-DedupJob PS> Get-DedupStatus -Volume D: --- So, once its deduped, you check. PS> FSUTIL REPARSEPOINT QUERY big.txt you should see that its a reparse point with that 0x800etc0013 code. Copy-paste big.txt to big2.txt and check it with the query, and it should tell you big2 is NOT a reparse point. NOW you have some files to test the boost library... You can't zip them up (they lose the dedup tag), you have to run boost binaries ON the computer in the sky. --- Finish --- Thanks for reading, Paul

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[COre] Pull request for enable_if_type
by Joel FALCOU 13 Aug '15

13 Aug '15

Hi, I just refurbished and pushed an old patch adding the enable_if_type SFINAE utility to core. https://github.com/boostorg/core/pull/15 I tried to keep it simple and make the doc proper. This utility has been laying around various boost library and was "reinvetned" in bosot.SIMD. I think it's worth being in core so code duplication is kept to a minimum. Comments welcome

2 3

[spirit] 1.59.0 rc3: compiler warning in real_impl.hpp
by Tobias Loew 13 Aug '15

13 Aug '15

Hi, with MSVC 11, 32-bit build I get a compiler warning in boost\spirit\home\qi\numeric\detail\real_impl.hpp : 287 warning C4244: '=' : conversion from 'unsigned __int64' to 'double', possible loss of data since I usually comile with warnings-as-errors this broke my build. Tobias -- View this message in context: http://boost.2283326.n4.nabble.com/spirit-1-59-0-rc3-compiler-warning-in-re… Sent from the Boost - Dev mailing list archive at Nabble.com.

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Any interest in a M:N green threading library?
by Xu Chen 13 Aug '15

13 Aug '15

Just cleanup some codes I wrote before, there is a M:N green threading library built on top of Boost.Thread and Boost.Coroutine, conceptually it works like goroutines in Go and (once existed) green threads in Rust. With some refinements, it now supports all C++11/14 threading standard, along with some extensions exist in Boost.Thread such as thread_group and chainable futures. It can be integrated with Boost.ASIO, all ASIO async functions can be used as sync ones in green threads, similar to Boost.ASIO/Boost.Coroutine integration. Also it has some facilities to communicate with foreign threads, can by used to integrate with external libs such as database drivers. The code can be found at https://github.com/windoze/boost.green_thread I don't know much about boostbook tools so the documents are kind of crippled, but I'll improve it if needed. Regards, Chen Xu

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Re: [boost] [build] Problems with VC14 and MSPDB140.DLL (was: [testing][teeks] MSVC-14 errors about MSPDB140.DLL)
by Adam Merz 12 Aug '15

12 Aug '15

Andrey Semashev <andrey.semashev <at> gmail.com> writes: > > I created a Connect ticket about it: > > https://connect.microsoft.com/VisualStudio/feedback/details/1651822/incorr ect-mspdb140-dll-version-picked-in-x86-x64-cross-tools-environment > This ticket appears to be set to private; would you mind editing it to public visibility so that we may upvote it? Regards,

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1.59.0 rc3 is now available
by Marshall Clow 12 Aug '15

12 Aug '15

New Release candidate files for 1.59.0 are available at: http://boost.cowic.de/rc/ RC3 should fix the problem with VC14 and MSPDB140.DLL. As always, the release managers would appreciate it if you download the candidate of your choice and give building it a try. Please report both success and failure, and anything else that is noteworthy. This helps ensure the candidates build OK before we push them out to SourceForge. The files (and associated md5s) are: MD5 (boost_1_59_0_rc3.7z) = 0a2e512844f3e30a6240f8139ee983f3 MD5 (boost_1_59_0_rc3.tar.bz2) = 6aa9a5c6a4ca1016edd0ed1178e3cb87 MD5 (boost_1_59_0_rc3.tar.gz) = 51528a0e3b33d9e10aaa311d9eb451e3 MD5 (boost_1_59_0_rc3.zip) = 08d29a2d85db3ebc8c6fdfa3a1f2b83c Thanks! -- The release managers P.S. Release notes are here: http://www.boost.org/users/history/version_1_59_0.html

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[context] msvc /SAFESEH
by Jeff Flinn 12 Aug '15

12 Aug '15

I need to build my application with /SAFESEH which uses boost coroutine which uses context. I'm getting the following link errors: 1>libboost_context-vc100-mt-gd-1_53.lib(jump_i386_ms_pe_masm.obj) : error LNK2026: module unsafe for SAFESEH image. 1>libboost_context-vc100-mt-gd-1_53.lib(make_i386_ms_pe_masm.obj) : error LNK2026: module unsafe for SAFESEH image. I've built boost static libs with the same MSVC vesion and options (sans /SAFESEH as it's not a compile/lib option) Compiler/linker versions: Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 16.00.40219.01 for 80x86 Microsoft (R) Incremental Linker Version 10.00.40219.01 Has anyone run into this and resolved the error? Any insight is appreciated. Thanks, Jeff

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[build] Overriding warning level for clang
by Edward Diener 11 Aug '15

11 Aug '15

In my user-config.jam for clang I have added: <warnings>on to the configuration section of the 'using clang' toolset. Nonetheless I still see '-Wall' on the command line when I compile. My other <cxxflags> settings which are part of the toolset are reflected by the command line. Even if I change to <warnings>off in the toolset I still see '-Wall' on the command line. Why is this not working and is there any way I can change the warning level for clang so that it is not 'Wall' on the command line ? The clang compiler is wonderful but with 'Wall' it spews out a boatload of information I normally do not need.

1 0

[build] Problems with VC14 and MSPDB140.DLL (was: [testing][teeks] MSVC-14 errors about MSPDB140.DLL)
by Andrey Semashev 11 Aug '15

11 Aug '15

On Sat, May 23, 2015 at 4:40 PM, Hartmut Kaiser <hartmut.kaiser(a)gmail.com> wrote: > >> All tests for Boost.Log (and I suspect any other built libraries) on MSVC- >> 14 >> are failing because of this error: >> >> LINK : fatal error LNK1101: incorrect MSPDB140.DLL version; recheck >> installation of this product > > My workaround was to edit the 'Path' env variable in one of the temp files > generated by bjam (b2_msvc_14.0_vcvarsall_amd64.cmd in your temp directory) > not to point to the x64 cross compiler, but to the native one. For me this > involved changing > > C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\BIN\amd64_x86 > > To > > C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\BIN\amd64 I encountered the same problem with VC14 RTM on my VM. This was a clean install of VC14 RTM, there were no CTPs or RCs installed on this machine. I removed the b2_msvc_14.0_vcvarsall*.cmd scripts and ran b2 with address-model=64 to build my tests so that these scripts are re-created from scratch, so it looks like there is a problem with how these scripts are generated by b2. I found 3 instances of mspdb140.dll on my system in these locations: C:\Program Files (x86)\Microsoft Visual Studio 14.0\Common7\IDE C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\bin C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\bin\amd64 The last two are for 32 and 64-bit native compilers. The first one, I assume, is for use by IDE. The problem is that the first path is listed in b2_msvc_14.0_vcvarsall_x86_amd64.cmd in the "SET Path=..." line prior to the compiler-specific paths. Removing it from the Path solved the problem. Could Boost.Build be adjusted so that the cmd files are generated correctly in the first place?

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[range] index adaptor with size_t as index_type
by Tobias Loew 10 Aug '15

10 Aug '15

>From version 1.55 to 1.56 the index_type of the index of the range index-adaptor was changed from size_t to ptr_diff which e.g. allows for negativ start values. But this has the side-effect that comparison with other size_t-values (e.g. a call to vector's size()) results in a compiler warning for comparing signed and unsigned values (on MSVC 11: warning C4018: '<' : signed/unsigned mismatch). I'm proposing a specialized version of the index adaptor, where the index_type is size_t and the start index is 0 (zero) and explicit specification of the start-value is not possible. A possible name could be "uindex". comments / critics / pros / cons are welcome Tobias -- View this message in context: http://boost.2283326.n4.nabble.com/range-index-adaptor-with-size-t-as-index… Sent from the Boost - Dev mailing list archive at Nabble.com.

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[python] Help with boost python build
by Andy Thomason 10 Aug '15

10 Aug '15

Hi All, I have had highly variable results with Boost.Python mostly due to linker errors or failures of Python to find DLLs. Python is not great at reporting why it fails, for example not naming failures to load dependent DLLs on Windows which does not make this a joyous experience. I have never managed to get any Boost.Python example - mine or otherwise - working on Windows and have had limited success on Linux. It is little surprise that all the examples on Stackoverflow avoid Bjam for builds. For my genetics library, I have an example that has a single source file and the Jamfile reads thus: python-extension genetics : bindings.cpp : <toolset>gcc:<cxxflags>-std=c++11 ; with: using python : 2.7 ; in ~/boost-config.jam ie. as minimal as possible. This builds well on linux (I am adding a library to the head of modular boost). When I run: python -c "import genetics" with appropriate PYTHONPATH I get a run-time symbol search error: ImportError: <...>/genetics.so: undefined symbol: _ZNK5boost6python7objects21py_function_impl_base9max_arityEv My guess would be that rather than this one symbol, Python is failing to load the shared lib: ~/modular-boost/bin.v2/libs/python/build/gcc-4.8/debug/libboost_python.so.1.59.0 As a postscript, It would be lovely if there were no static or dynamic libraries to link with when compiling with Boost.Python and a unity build would be a nice option as this would bypass linker and runtime related errors. It would probably compile faster in my long experience with such projects. Any help would be welcome. Andy. --- This email has been checked for viruses by Avast antivirus software. http://www.avast.com

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[regression tests] Adding regression tests for mingw(-64)/gcc and clang on Windows
by Edward Diener 10 Aug '15

10 Aug '15

I don't know if I am supposed to ask questions about running regression tests in this mailing list or in the Boost testing mailing list, but I will try here first. The Boost testing mailing list seems to be for actual test result problems and the like. For a long time now we have had no regression tests for mingw/gcc or clang targeting gcc on Windows. The only regression tests for Windows are for various releases of VC++. I have limited resources but I have a laptop usually sitting idle, except for occasional travel where I take it with me, and I am set up to run tests on that machine for mingw/gcc and clang on Windows. However mingw/gcc and clang have limitations when running tests in that, both relying on various mingw/gcc implementations, the path to the implementation must be added at the beginning of the PATH before running any of the tests. I have already argued with the mingw-64 people about this necessity but they are adamant that this should be the case even just to compile/link properly ( and have setup their directory structure to enforce it ), and I don't want to waste my breath further with them. Currently I have a batch file that does that for me when running tests for aany particular library, but I don't know how that can be achieved when running the regression tests unless possibly I run regression tests for only a single toolset at a time, and manipulate the PATH accodingly. But that is really time consuming since evidently all of Boost must be downloaded to the run directory each time. Is there an easy solution to this or do I have to look at run.py and try modify it accordingly ( I know Python well ) ? Also I notice on the Boost web site regression test page ( http://www.boost.org/development/running_regression_tests.html ) that the options of the regression tests are somewhat documented but none of the commands are documented. Is there further documentation about the regression test commands anywhere ?

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Build Error VS14 + Intel 15.0 (Update 4, the latest)
by degski 10 Aug '15

10 Aug '15

I have encountered the following error when building boost 1.58 (and 1.59-b1): C:/boost_1_58_0/tools/build/src/tools\intel-win.jam:194: in configure-really from module intel-win error: msvc 14 not supported for intel toolset version 15.0 I'm using the following line to build boost: bjam -a -d+2 --toolset=intel-15.0-vc14 "-sINTEL_PATH=C:\Program Files (x86)\Intel\Composer XE 2015\bin\intel64" cxxflags="/O2 /Quse-intel-optimized-headers /Qstd=c++14 /Qipo /Zc:forScope /Oi /MT /EHsc /Qparallel" "-sINTEL_BASE_MSVC_TOOLSET=vc-14_0" "-sINTEL_VERSION=15" "-sZLIB_SOURCE=%HOME%\zlib-1.2.8" "-sBZIP2_SOURCE=%HOME%\bzip2-1.0.6" variant=release instruction-set=nehalem threading=multi link=static runtime-link=static --stagedir=stage64_static address-model=64 architecture=x86 --without-python --without-mpi --disable-filesystem2 stage > icc_log_stage.log The above worked fine with VS11 and Intel 15.0. The combo (VS14/ICC15) is obviously supported by (MS/Intel), and works fine in the IDE (Community Edition). I confirm the problem with bootstrap.bat, this has been around for a long time, and always had to build the 32bit version first. I ran into it as I have decided to stop building 32-bit. The obvious work-around is to build bjam seperately, not a killer for me, but might be for some. The main issue I report, is though and it would be a shame if the 1.59 release would not allow for that combo, as finally MS have released a free, non-crippled, release of their IDE with (finally, in 2015) full support for C++11... I'm happy to test some things out if necessary, I'm not capable of adressing the issue though...

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Re: [boost] [asio-users] [http] Formal review of Boost.Http
by Lee Clagett 09 Aug '15

09 Aug '15

On Sat, Aug 8, 2015 at 5:16 AM, Vinícius dos Santos Oliveira < vinipsmaker(a)users.sf.net> wrote: > 2015-08-08 0:10 GMT-03:00 Lee Clagett <forum(a)leeclagett.com>: > >> FWIW it should be possible to do client and server side pipelining with >> this design right now. The reads and writes of the HTTP Socket concept >> should be (and currently are by `basic_socket`) handled independently. >> Since the notification for a write completion is based on the lower layer >> write completion, and NOT whether a HTTP response was received, multiple >> (pipelined) requests should be possible by a client. Similarly, this design >> should allow servers to handle pipelined requests in parrallel. Providing a >> framework for client or server pipelining will require more work, and >> should probably not be a part of the Socket concept. In fact - >> > > The current design **does** support pipelining. Some HTTP clients disable > pipelining because some buggy servers will get confuse. This won't happen > with Boost.Http (there are tests to ensure pipelning is working). > > What the current design does **not** support is handling pipelined > requests concurrently. When you starting read a request, the write_state[1] > will change to finished until the fully request is received, so you can't > get multiple request while you don't issue the replies. This behaviour is > explained in the ServerSocket concept[2]. > > There are just too many ways to allow HTTP concurrent pipeline that would > be transparent for the user, but all of them are heavier. If I was to allow > handling multiple concurrent HTTP pipelined requests, I'd expose user > cooperation, so the abstraction doesn't become so heavy. The user would > need to be aware if the reply for some request can already be delivered or > not. Of course this means the socket will need to remember order and attach > some id to the request messages. It can be problematic in alternative > backends because the id could be of a different type and makes it difficult > to use the same message type with different HTTP backends. What do you > think? The design would just be more complex for not much gain. HTTP/2.0 > allow real multiplexing and doesn't show this problem. > I agree that providing any pipelining framework in the library is probably unnecessary right now. However, the design should not inhibit such functionality from being added (which I do not think is a problem with this design). > I think the ServerSocket concept should be removed entirely. The >> `http::basic_socket<...>` models both concepts, so theres lots of server >> specific code in it, which seems confusing to me (is this really a "basic" >> socket?). >> > > basic_socket uses basic_ prefix just like basic_string. > I was asking whether basic_socket should NOT model the http::ServerSocket concept. I understood the naming convention, and the decision to provide the implementation as a configurable template. The problem is the lack of composability. If a different http::Socket concept is desired (someone not using ASIO, etc.), then the http::ServerSocket concept has to be re-implemented also since there is no other implementation. The obvious way is to achieve composability is to use inheritance with: `http::basic_server_socket<Socket>` where `Socket` is a http::Socket concept. Inheritance in this situation has its drawbacks, for sure (a virtual destructor should be considered). > I think standalone functions for typical client and server operations can >> be implemented as "composed" operations similar to `asio::async_write`. The >> documentation will have to be explicit on what the composed function is >> doing so that users know whether the Socket concept has outstanding reads >> or writes (and therefore cannot do certain operations until the handler is >> invoked). In fact, if there is a server operation that _cannot_ be done >> with the Socket concept, then the concept probably needs to be re-designed. >> > > About "users know whether..." seems like a bad idea if I want to deliver > multiple backends. Some implementation details should just be abstracted > away. > > http::SocketServer implementations manipulate the state of the http::Socket (and indirectly the asio::tcp::socket), making some actions unavailable after invoking those functions. For example, after invoking `async_write_response`, no writes on the http::Socket/http::ServerSocket or asio::ip::tcp::socket can occur until the callback is invoked because it calls asio::write on the asio::ip::tcp::socket directly. So unless I am incorrect, it is important for the users to know whats being manipulated (the effects). I don't understand what you mean by "if there is a server operation that > cannot be done with the Socket concept [...]". Boost.Http has two concepts, > ServerSocket and Socket. Socket concept will be useful to client-side HTTP > and that's the reason why there are two concepts. > > The http::ServerSocket concept requires a http::Socket to write its messages, but does the http::ServerSocket concept need to be a refinement of the http::Socket concept? This implies a strong relationship. The current specification looks like a http::ServerTraits concept - its specifying how a http::Socket is being used in situations specific to servers. There doesn't appear to be any additional state tracking needed for the http::ServerSocket functions, which is why I suggested standalone functions (I didn't see the FileServer section). In fact implementation can be inverted; make all of the current implementations for http::ServerSocket standalone functions, and then have the default http::ServerTraits implementation call the standalone versions of the functions. The http::ServerTraits should then take a http::Socket as an argument for each of the functions. This complete de-coupling would allow someone to independently change the behavior of any related server functions, even while using the same http::Socket object. [1] https://boostgsoc14.github.io/boost.http/reference/write_state.html > [2] "The ServerSocket object MUST prevent the user from issuing new > replies while [...]", > https://boostgsoc14.github.io/boost.http/reference/server_socket_concept.ht… > > Lee

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[Utility] intuitive scoping with BOOST_WITH
by Marcel Ebmer 08 Aug '15

08 Aug '15

Hi Everyone, What if you could do std::mutex the_mutex; using Lock = std::unique_lock<std::mutex>; void f() { with(Lock{the_mutex}) { do_something(); do_other_thing(); } } *...or...* struct Pushed_matrix { Pushed_matrix() { glPushMatrix(); } ~Pushed_matrix() { glPopMatrix(); } }; void f() { with(Pushed_matrix{}) draw_something(); } At C++Now (2015), I presented this idea of mine and a macro implementation (BOOST_WITH) in a lightning talk. Since reception was good and more serious than the talk itself, I continued to work on it. I would appreciate informal review and opinions: https://github.com/maysl/BOOST_WITH Marcel

3 3

1.59.0 rc2 is now available
by Marshall Clow 08 Aug '15

08 Aug '15

Release candidate files for 1.59.0 are available at: http://boost.cowic.de/rc/ (rc1 failed a smoke test) As always, the release managers would appreciate it if you download the candidate of your choice and give building it a try. Please report both success and failure, and anything else that is noteworthy. This helps ensure the candidates build OK before we push them out to SourceForge. The files (and associated md5s) are: MD5 (boost_1_59_0_rc2.7z) = 1854999b8d32ba89acbf4384fe55e0ab MD5 (boost_1_59_0_rc2.tar.bz2) = 1783f07dd4736ffd9fc97874ce4ef4bf MD5 (boost_1_59_0_rc2.tar.gz) = 47e6db09fd7e1265b9b7046f654e9a72 MD5 (boost_1_59_0_rc2.zip) = 9061c5bbc3399f3f220036e896c202aa Thanks! -- The release managers P.S. Release notes are here: http://www.boost.org/users/history/version_1_59_0.html

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[1.59] Still unmerged changes in the super-project
by John Maddock 08 Aug '15

08 Aug '15

There are a number of unmerged changes in develop of the super-project that look like they should really be in release, in particular: * Jamroot, contains amongst other things a very old fix for Oracle C++ support, without which building with Oracle is more or less broken. In fact unmerged commits on this file go back to....wait for it... 2011 ! * bootstrap.bat has fixes for some rather embarrassing typos. * bootstrap.sh has lots of fixes, also going back to 2011. Those were the "highlights" that stood out to me, the full list with unmerged changes is: .gitmodules | 613 ++++++++++++++++++------------------ .travis.yml | 6 +- Jamroot | 32 +- boostcpp.jam | 47 +-- boostcpp.py | 459 --------------------------- bootstrap.bat | 4 +- bootstrap.sh | 24 +- doc/Jamfile.v2 | 2 - doc/src/boost.xml | 2 - libs/libraries.htm | 10 +- libs/maintainers.txt | 5 +- status/Jamfile.v2 | 4 - status/explicit-failures-markup.xml | 41 +-- tools/Jamfile.v2 | 2 +- 14 files changed, 336 insertions(+), 915 deletions Best, John.

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[iostreams] Ticket #5237 - Chance to get fix applied into Boost 1.59?
by Deniz Bahadir 08 Aug '15

08 Aug '15

Hi everyone, in our application we use Boost.Iostreams with GZip functionality to write some data into gzipped output-files. Eventually we realized, that we would get corrupted output-files if no data was available that could be written to the output-file By looking for a patch we stumbled across an issue-report [1] which seems to be open for more than 4 years, although a simple fix was already provided in its comments 3,5 years ago. My question is: Can somebody apply that fix to the development branch and could it still make it into the upcoming Boost 1.59 release? Thanks, Deniz [1] https://svn.boost.org/trac/boost/ticket/5237

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Getting started with Boost
by Prathamesh Dahale 08 Aug '15

08 Aug '15

Hello, I am Prathamesh Dahale, third year computer engineering student. I am interested in contributing to Boost through gsoc 2016. I know c and c++, I am familiar with c++ STL and I have very good programming skills. I participate in many online programming contests. my handle on codechef.com is 'miracle003'. I would like to utilize my skills for contributing to Boost and I am interested in doing some project with Boost in gsoc 2016. from where i should start?

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Re: [boost] [asio-users] [http] Formal review of Boost.Http
by Lee Clagett 08 Aug '15

08 Aug '15

Sorry for any duplicates and top posting, but I didn't reply-all, so boost got dropped (which was probably more important). And this likely ruins some mail clients (again sorry!). On Fri, Aug 7, 2015 at 11:10 PM, Lee Clagett <forum(a)leeclagett.com> wrote: > On Fri, Aug 7, 2015 at 6:29 PM, Vinícius dos Santos Oliveira < > vinipsmaker(a)users.sf.net> wrote: > >> 2015-08-07 12:53 GMT-03:00 Niall Douglas <s_sourceforge(a)nedprod.com>: >> >>> I do not believe Http is ready for peer review for these reasons, and >>> I personally would urge you withdraw it until you have fixed these >>> issues and then come back to us. If you do not withdraw it, I will >>> vote for rejection. >>> >> ...[large snip]... >> > >>> * I don't understand why you cannot issue more than one async read at >>> a time nor async write at a time. In something like pipelined HTTP >>> that seems like a very common pattern. I smell a potential design >>> flaw, and while the docs mention a "queue_socket" I can't see such a >>> thing in the reference section. >>> >> >> Too much synchronization and buffering. >> >> The pipeline has the following requests: >> >> A => B => C >> >> If I were to allow replies to request B, the design would be more >> complex, increasing the difficult to implement alternative backends and >> everyone's life. Also, the reply to request B cannot actually be sent while >> the reply to request A is on hold. This means that the whole response to >> request B would need buffering and if response B is a video live stream, >> this means an implicit (the user cannot know) crash after an unfortunate >> memory exhaustion. I couldn't claim a **lightweight** server if this >> excessive buffering was to occur. I couldn't claim the project is >> appropriate for embedded devices if I had chosen the buffering approach. >> It's a trade-off. I should write about it in the "design choice" of the >> documentation. >> >> HTTP/2.0 does have proper multiplexing and it can be more useful to >> respond several requests without "head of line blocking". >> >> A queue socket is a concept, I don't provide one. I can look into how >> make the documentation less confusing by adding a page exclusively >> dedicated to explain the problem it solves. Would that work for you? >> >> > FWIW it should be possible to do client and server side pipelining with > this design right now. The reads and writes of the HTTP Socket concept > should be (and currently are by `basic_socket`) handled independently. > Since the notification for a write completion is based on the lower layer > write completion, and NOT whether a HTTP response was received, multiple > (pipelined) requests should be possible by a client. Similarly, this design > should allow servers to handle pipelined requests in parrallel. Providing a > framework for client or server pipelining will require more work, and > should probably not be a part of the Socket concept. In fact - > > I think the ServerSocket concept should be removed entirely. The > `http::basic_socket<...>` models both concepts, so theres lots of server > specific code in it, which seems confusing to me (is this really a "basic" > socket?). I think standalone functions for typical client and server > operations can be implemented as "composed" operations similar to > `asio::async_write`. The documentation will have to be explicit on what the > composed function is doing so that users know whether the Socket concept > has outstanding reads or writes (and therefore cannot do certain operations > until the handler is invoked). In fact, if there is a server operation that > _cannot_ be done with the Socket concept, then the concept probably needs > to be re-designed. > > Lee >

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Is master open for release 1.59?
by Vicente J. Botet Escriba 08 Aug '15

08 Aug '15

Hi, I was on vacations. Is the master branch open for merge? Best, Vicente

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[Property Tree] Comments in info format
by Gavin McNiff 05 Aug '15

05 Aug '15

First time posting, so hopefully no grave faux pas! I have found the Property Tree info format very useful for config files. However, the in-built comment ";" can be a little limiting. In particular, I miss not being able to comment out an entire block. To this end I have being modifying the relevant header to file to allow ; // and -- as inline comments and /* */ as a block comment. These are familiar to many users. Naturally, with every Boost release I have to re-patch this file, so I thought maybe the info format could be updated to allow comments in these styles. Since the format is not any kind of official format and adding new comment styles should not break existing files, I would hope there should be no major objections. I have taken the liberty of attaching the updated header file, as well as the adapted test file. The _gmcn suffix is just for identification purposes. The changes in the code are marked with !!! GMcN !!!. The changes pass in the built-in tests and my own usage tests. Best regards Gavin McNiff

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boost::asio and I2P connection handling.
by Janusz Zradomia 05 Aug '15

05 Aug '15

Hello. I would like to extend the ASIO (in boost::asio) by adding support for new virtual protocols. For example i2p, it is similar to Tor but it works with equivalent of .onion hidden servers, and is not used to connect to "normal Internet" usually. It works like this: - the end-points, equivalent of the ip4/ip6 address, is a very long string (around 500-1000 characters, it is technically the public key of data) - the end-point address is often expressed as shorter version of the address, that is around 50 characters afair, in two possible formats (b32 and b64) - user can create new i2p listening socket for TCP-like data (for stream of bytes), or for UDP-like data (message oriented). On creation of the listening socket you can get a new own "address" as above. Or, you can on creation/before creation tell it to reuse an previously created address by providing the std::string with private key of it (that you saved previously) - user can connect to an i2p address. When connecting, he is getting a new endpoint from which he connects, or he can reuse old one by loading the private key as above. - there exists naming lookup system, that allows to convert domain-name strings like "zzz.i2p" into proper i2p address Can I add such new class of protocol on top of ASIO? Which classes I need to extend (create child class)? Where exactly would each of the listed above functions go?

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[http] Formal review starts on Friday
by Bjorn Reese 05 Aug '15

05 Aug '15

This is a short notice that the formal review for the Boost.Http library starts on Friday and will last for ten days: from August 7th until August 16th. A proper announcement will be made on Friday, which will include links to the source code and the documentation to be reviewed. As a courtesy to the ASIO community we encourage your participation in the formal review as well.

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[1.59] SVG's not showing up in beta
by John Maddock 05 Aug '15

05 Aug '15

SVG graphics used in documentation are still absent from the (beta) website, see for example: http://www.boost.org/doc/libs/1_59_0_b1/libs/math/doc/html/math_toolkit/sf_… I assume a script somewhere needs updating? Thanks, John.

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Trying out QVM with multiple library implementations
by Andrew Hundt 05 Aug '15

05 Aug '15

I'd really like to try out QVM because I have to switch between a half dozen matrix, vector and quaternion types constantly and would prefer not to write functions for each conversion and operations between them. Examples of the formats I need to handle are: *Eigen <http://eigen.tuxfamily.org/index.php?title=Main_Page>:* Eigen::Affine3d Eigen::Quaterniond + rotation and translation versions *vrep <http://www.coppeliarobotics.com/helpFiles/en/apiFunctions.htm#simBuildMatri…>:* float[3] (vrep vector) float[4] (vrep quaternion) float[12] (vrep homogeneous transform matrix) *cisstVector <https://github.com/jhu-cisst/cisst/tree/master/cisstVector>:* vctDynamicVector <https://github.com/jhu-cisst/cisst/blob/master/cisstVector/vctDynamicVector…> vctQuaternion <https://github.com/jhu-cisst/cisst/blob/master/cisstVector/vctQuaternion.h> vctDynamicMatrix <https://github.com/jhu-cisst/cisst/blob/master/cisstVector/vctDynamicMatrix…> There are also fixed versions of the "Dynamic" objects. + rotation & translations Is there any particular concerns I need to take regarding alignment, ordering (row vs column major) etc? For example, the ordering of the quaternion data components differ between eigen and rep: // 0123 // vrep quat is ordered xyzw, // eigen quat is ordered wxyz Any advice on how to go about this would be appreciated so I can try QVM out! Cheers! Andrew Hundt

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Broken links in 1.58.0 release notes
by Jonathan Wakely 04 Aug '15

04 Aug '15

At http://www.boost.org/users/history/version_1_58_0.html the release notes on the breaking change for Variant say "See get.hpp and polymorphic_get.hpp descriptions for more info" but both hyperlinks are broken.

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Review Request: QVM (generic Quaternion, Vector and Matrix operations library)
by Emil Dotchevski 04 Aug '15

04 Aug '15

Boost QVM defines a set of generic functions and operator overloads for working with quaternions, vectors and matrices of static size. The library also defines vector and matrix data types, however it allows users to introduce their own types by specializing the q_traits, v_traits and m_traits templates. Online documentation and a link to download the source code under the Boost license is available at http://www.revergestudios.com/boost-qvm/. I would like to thank Adam Wulkiewicz for volunteering to be the review manager for QVM and for his valuable initial feedback. Thanks, Emil Dotchevski

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BOOST_NO_CXX11_CONSTEXPR and msvc-14.0
by Peter Dimov 04 Aug '15

04 Aug '15

I see that BOOST_NO_CXX11_CONSTEXPR is no longer being defined for msvc-14.0. Even the RTM version has spotty support for constexpr though; the techniques in my metaprogramming article, for example, don't work. One simple example that fails is #include <type_traits> template< int I > struct X { }; template<class... T> constexpr int f( T... t ) { return 1; } template< class... T > struct Y: X< f(std::is_same<T, void>::value...) > { }; Y<void, void, void> y; int main() { } Another is #include <type_traits> template< class... T > struct X { static constexpr bool v[] = { std::is_same<T, void>::value... }; }; int main() { }

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[serialization] Errors when testing withe mingw-64/gcc on Windows
by Edward Diener 04 Aug '15

04 Aug '15

When running serialization tests with mingw-64/gcc on Windows I get repeated errors of the form: ..\..\../boost/archive/detail/basic_oarchive.hpp:64:5: error: function 'boost::archive::detail::helper_collection& boost::archive::detail::basic_oarchive::get_helper_collection()' definition is marked dllimport get_helper_collection(){ Is this a known problem ? Testing with VC++ does not give any errors.

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Boost 1_59_0_b1_rc1 is available for testing
by Marshall Clow 02 Aug '15

02 Aug '15

Release candidate files for 1.59.0 beta 1 are available at http://boost.cowic.de/rc/ As always, the release managers would appreciate it if you download the candidate of your choice and give building it a try. Please report both success and failure, and anything else that is noteworthy. This helps ensure the candidates build OK before we push them out to SourceForge. The files (and associated md5s) are: MD5 (boost_1_59_0_b1_rc1.7z) = f54a97e5ee7f8e3d04cd9af8396e30f9 MD5 (boost_1_59_0_b1_rc1.tar.bz2) = 9804305aae0c9de9f8cfc02e3de75167 MD5 (boost_1_59_0_b1_rc1.tar.gz) = e584770bd76885c123a0426d24466fe2 MD5 (boost_1_59_0_b1_rc1.zip) = ee34f223aa789a6b3f727cb9480651ed Thanks! -- The release managers

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[Log, Filesystem] Build errors using B2 and Jamfiles distributed with Boost
by Norbert Wenzel 02 Aug '15

02 Aug '15

I'm a lazy guy so I try to use Boost.Build whenever I can. That way I can simply download the Boost tarball, extract it into my project's directory and use the Jamfiles distributed with Boost. Recently I switched to 1.58 and my project setup failed to build, complaining that Filesystem would be built twice with different settings* (actually it would be built one time without any specific settings and one time with a sane set for my platform). I managed to create a "simple" project setup to reproduce this error. I created a library (testlib) with a single extern C function that fills a user provided buffer with the current working directoy. This library uses Boost.Filesystem internally. Therefore the lib's Jamfile also references the Jamfile distributed with Filesystem. I created an executable (test) that calls the lib function and also uses Filesystem to get the parent directory of the current working directory (as reported by the lib function). This setup builds fine as long as I use cout to write the paths in the test exe. When I replace cout with Boost.Log (and therefore also reference the boost_log and boost_log_setup projects) this setup only builds with Boost 1.57. From 1.58 on (also tested with 1.59.b1) the project does not build because Filesystem would be built twice with different settings. Since the error can be triggered by changing the Boost version I reckon this is due to a change in one of the Jamfiles (probably Boost.Log) and not a problem of Boost.Build per se. But for reference I use Boost.Jam Version 2014.03 (the one distributed with 1.58). Since the "simple" setup consists of a few files and directories I've made it available via Github: https://github.com/norbertwenzel/boost-build-problem I've posted this here and not to Boost.Build ML since I suspect this is due to a change in one of the two libraries mentioned and not a bug or misuse in/of Boost.Build. Any help appreciated. thanks, Norbert *) The exact error message I got: error: Name clash for '<p/tmp/b2_problem/external/boost_1_58_0/bin.v2/libs/filesystem/build/gcc-5.1.0/debug>libboost_filesystem.so.1.58.0' error: error: Tried to build the target twice, with property sets having error: these incompatible properties: error: error: - none error: - <abi>sysv <binary-format>elf <log-api>generic <preserve-test-targets>on <python-debugging>off <python>2.7 <testing.execute>on <threadapi>pthread error: error: Please make sure to have consistent requirements for these error: properties everywhere in your project, especially for install error: targets.

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[http] Scheduling a review for Boost.Http
by Bjorn Reese 01 Aug '15

01 Aug '15

I am about to schedule a formal review for Boost.Http (see blincubator for links.) If there are no objections I suggest that the review is held from August 17 to 30.

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Boost 1.53 Libraries for Android
by Ian Calegory 31 Jul '15

31 Jul '15

I've compiled and made available for download the Boost C++ 1.53 Libraries for Android. This enables cross platform code in C++ that uses the Boost libraries. It is especially useful for Embarcadero's FireMonkey environment in RAD Studio, where cross platform code written in C++ can run on Windows, Android, Mac OS X, and iOS. Conceivably, cross platform code can be written using the Boost libraries that can run on all of the aforementioned environments. (The other platform libraries would have to be available, of course, and RAD Studio comes with Boost pre-compiled for Windows; Boost of course is widely available for Mac OS X.) Here is my web page where the include files and .a library files (one file for each of the four main Android architectures) is available for download: http://www.mandelmania.net/boost.html Any comments welcome. logo final small 11 Ian Calegory Software Engineer <mailto:ianc102002@yahoo.com> ianc102002(a)yahoo.com <http://www.mandelmania.net/> http://www.mandelmania.net

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devector feedback request
by Benedek Thaler 30 Jul '15

30 Jul '15

Dear Boost, I'm happy to announce the new devector container developed as part of the GSoC programme reached a presentable state. I invite you to take a look and ask for feedback. Main features: - every std::vector feature - front operations with amortized linear complexity - optional small buffer optimization - customizable growth policy (see the docs) - unsafe methods for the brave and performance addicts Documentation: - Intro: http://erenon.hu/container/container/non_standard_containers.html#container… - Usage: http://erenon.hu/container/container/examples.html#container.examples.devec… - API: http://erenon.hu/container/boost/container/devector.html#idp86138944 Code: - Implementation: https://github.com/erenon/container/blob/devector/include/boost/container/d… - Tests: https://github.com/erenon/container/blob/devector/test/devector_test.cpp Thanks, Benedek

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[Log] Running in a separate thread
by Andrew Hundt 29 Jul '15

29 Jul '15

I really only need some of the functionality of BOOST_LOG_TRIVIAL, perhaps plus loving to a file in addition to the console. However, my only true need is that all the work (or as much as possible) must be done in a separate thread so as not to slow the current thread down. Right now when I use BOOST_LOG_TRIVIAL as is it causes latency in my network communications which have soft realtime requirements so I've had to comment all of my logs out. Is there a straightforward non-intrusive solution to having as much of the work as possible for boost.log be done in a separate thread? Thanks for your help! Cheers! Andrew Hundt

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Boost.DLL formal review result
by Vladimir Prus 28 Jul '15

28 Jul '15

The Boost.DLL library is accepted. Congratulations to Antony, and thanks for everybody who reviewed the library! The votes were as follows: - Ralf Globisch - Yes - Klaim - Joël Lamotte - Yes - Niall Douglas - Yes, conditionally - John P Fletcher - Yes - Bjorn Reese - Yes - Edward Diener - Yes - Rodrigo Madera - Yes - Richard - Yes I'd like to also thank Thomas Trummer, Rob Stewart and Ion Gaztañaga for their contribution to review. The key suggestions from the review are listed below. None is critical enough to become a formal prerequisite, or require a mini-review. The library can be added when Antony feels its ready. Naming ----------- There was a concern that "DLL" might sound windows specific, and search for best terminology. This does not seem all that important, as soon as documentation introduces the terminology it uses, and is consistent. OSX support ------------------- The library was found not to work on OSX; I believe this issue was already fixed off-list with help from Rodrigo. Documentation ---------------------- Several people requested improvements. Bjorn and John, in particular, pointed out specific issues. This seems to be the post important change prior to adding the library. Dependencies on Boost and system headers ---------------------------------------------------------------- It was suggested that the library does not depend on other Boost C++ Libraries. While it might be helpful to some users, I find it logically impossible for a Boost formal review to request that dependencies on Boost libraries be removed. It was also mentioned that Boost.DLL is header-only library and includes system headers that can bring a lot of symbols and maybe macros. I don't think an actual problem was reported, though, and there is no way to avoid the problem while staying header-only. It's up to the author to consider these suggestions and do something, or don't do anything. Continuous integration -------------------------------- There was a recommendation from Niall to improve CI of the library, including static analysis, valgrind, Windows CI, showing CI status in documentation and so forth. These are good suggestions. At the same time, they are not specific to Boost.DLL, and it's not the goal of a formal review to create new generic development process requirements. Many existing libraries of indisputably high quality do not have these requested mechanisms. Therefore, the author can act on these suggestions as he sees fit. Thanks, -- Vladimir Prus http://vladimirprus.com

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BGL pull requests
by Mads Jensen 27 Jul '15

27 Jul '15

Hi, There are many quite trivial pull requests on Github for BGL. Can the project responsible please have a look at them? Most of them just fix typos and add more clarity to the documentation. Thank you, -- Med venlig hilsen / Kind regards, Mads Jensen Gunnery Sergeant Hartman: What's your excuse? Private Cowboy: Sir, excuse for what, sir? Gunnery Sergeant Hartman: I'm asking the fucking questions here, private! Do you understand? -- Full Metal Jacket

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[mpl] Problem with VC++14 and boost::mpl::size_t
by Edward Diener 27 Jul '15

27 Jul '15

The just released VC++14 has a problem with the boost::mpl::size_t template. After preprocessing it sees: namespace boost { namespace mpl { template< std::size_t N > struct size_t { static const std::size_t value = N; typedef size_t type; typedef std::size_t value_type; typedef integral_c_tag tag; typedef boost::mpl::size_t< static_cast<std::size_t>((value + 1)) > next; typedef boost::mpl::size_t< static_cast<std::size_t>((value - 1)) > prior; operator std::size_t() const { return static_cast<std::size_t>(this->value); } }; template< std::size_t N > std::size_t const boost::mpl::size_t< N >::value; }} and gives the error message: size_t.cpp(nnn): error C2872: 'size_t': ambiguous symbol predefined C++ types (compiler internal)(16): note: could be 'unsigned int size_t' size_t.cpp(nnn): note: or 'boost::mpl::size_t' pointing to the line after it encounters 'struct size_t' as far as I can make out ( you need to preprocess the size_t.cpp test, comment out the #line directives and run the test against the preprocessed result to see what the compiler is objecting to ). It therefore fails a number of mpl tests which all prior versions of VC++ pass. It flags this error in 5 mpl tests which use the boost::mpl::size_t integral wrapper, among which the easiest to analyze is the size_t.cpp test itself. Anybody have any idea what is going on here with the compiler, or whether it can be fixed somehow in VC++14 for the mpl code ?

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