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'is_palindrome' and 'const char*'
by Зайцев Александр 14 Aug '16

14 Aug '16

Hello. I have some question about some case for 'is_palindrome' algo. 'is_palindrome' algorithm checks a sequence - if sequence is a palindromeor empty, function returns true, in other cases returns false. But in case e.g. "a" (is_palindrome("a")) result is false, because "a" = {'a', '\0'}. And maybe this behaviour is unexpected for users. So... what do you think about it? Should I implement special version for const char* or not? -- Best regards, Zaitsev Alexander

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filesystem 1.61.0 and cygwin: Windows assumed, posix expected
by Frédéric Bron 12 Aug '16

12 Aug '16

Hi, On cygwin, the following program #include <iostream> #include <boost/filesystem.hpp> int main() { auto p = boost::filesystem::path{"foo"}; p /= "bar"; std::cout << p.string() << '\n'; return 0; } outputs: foo\bar but cygwin is a posix system and I expect: foo/bar I read in the doc that "User-defined BOOST_POSIX_API and BOOST_WINDOWS_API macros are no longer supported." So how can I have posix support on cygwin? Thanks, Frédéric

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[graph] Sync develop with master?
by Murray Cumming 12 Aug '16

12 Aug '16

Now that Boost 1.61 is out, it would be great if the various fixes in boost graph's develop branch could be merged/cherry-picked/whatever to master, please. There seem to be a couple of years of fixes that have not appeared in a release. -- Murray Cumming murrayc(a)murrayc.com www.murrayc.com

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[thread][circular_buffer] Unmerged changes for 1.62
by Andrey Semashev 12 Aug '16

12 Aug '16

Hi, There are a couple of my PRs hanging for quite some time that I'd like to be merged before 1.62 is released: https://github.com/boostorg/circular_buffer/pull/9 Changes the default implementation of circular_buffer in debug mode to the thread-safe by default. https://github.com/boostorg/thread/pull/92 Fixes compilation of Boost.Thread with MSVC-8. There is also https://github.com/boostorg/thread/pull/94, which is not mine but it looks like it fixes a genuine problem. Could someone have a look at them and merge? Thanks.

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[interprocess] weirdest bug with offset_ptr equality comparison
by Joaquin M López Muñoz 11 Aug '16

11 Aug '16

The following is a distilled testcase after the ticket reported at https://svn.boost.org/trac/boost/ticket/12367 #include <boost/interprocess/allocators/allocator.hpp> #include <boost/interprocess/managed_shared_memory.hpp> template<typename Allocator> struct node_base { using allocator_type=Allocator; }; template<typename Allocator> struct node_impl { using value_type= typename Allocator::template rebind<node_impl>::other::value_type; }; template<typename Super> struct trampoline:node_impl<typename Super::allocator_type>{}; template<typename Super> struct node:Super,trampoline<Super>{}; int main() { using node_type= node< node< node_base< boost::interprocess::allocator< int, boost::interprocess::managed_shared_memory::segment_manager > > > >; using pointer=boost::interprocess::offset_ptr<node_type>; pointer p=nullptr; bool b=(p==p); // here's the problem } This works fine with GCC. When compiled with Visual Studio 2015, we get: 1>------ Build started: Project: borrame2015, Configuration: Debug x64 ------ 1> sandbox.cpp 1>d:\usr\joaquin\proyectos\boost-repo\trunk\boost\interprocess\detail\mpl.hpp(74): error C2594: 'argument': ambiguous conversions from 'node<node<node_base<boost::interprocess::allocator<int,boost::interprocess::segment_manager<CharType,MemoryAlgorithm,IndexType>>>>> ' to 'node_impl<boost::interprocess::allocator<int,boost::interprocess::segment_manager<CharType,MemoryAlgorithm,IndexType>>> ' 1> with 1> [ 1> CharType=char, 1> MemoryAlgorithm=boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family,boost::interprocess::offset_ptr<void,ptrdiff_t,size_t,0x00>,0x00>, 1> IndexType=boost::interprocess::iset_index 1> ] 1> d:\usr\joaquin\proyectos\borrame2015\sandbox.cpp(39): note: see reference to class template instantiation 'boost::interprocess::ipcdetail::is_convertible<node_type *,PointedType *>' being compiled 1> with 1> [ 1> PointedType=node_impl<boost::interprocess::allocator<int,boost::interprocess::segment_manager<char,boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family,boost::interprocess::offset_ptr<void,ptrdiff_t,size_t,0x00>,0x00>,boost::interprocess::iset_index>>> 1> ] ========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ========== Note that it is the line bool b=(p==p); // here's the problem that triggers the problem; if removed, compilation goes fine. Almost anything in the testcase program is needed for the problem to arise: - using node_type=node<node<...>> --> using node_type=node<...> (just one node level): compilation OK - remove using value_type=... in node_impl: compilation OK - rebind<node_mpl> --> rebind<char>: compilation OK - use std::allocator rather than boost::interprocess::allocator: compilation OK Ion, I'm totally puzzled by this and unable to navigate through the internals of Boost.Interprocess. Totally at your disposal if you need further info or assistance running tests etc. Thank you, Joaquín M López Muñoz

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[contract] noexcept and throwing handlers
by Lorenzo Caminiti 10 Aug '16

10 Aug '16

Hello all, I would like to discuss contracts and exception specifications (e.g., noexcept) specifically with respect to what Boost.Contract does. On one hand, it seems silly to allow a contract failure handler to throw an exception to only translate such an exception into a call to terminate() for noexcept functions. However, noexcept can be considered part of the function contract (namely, the contract that says the function shall not throw) and contract failure handlers should not be allowed to break such contract, not even when they are allowed to throw. For example consider a noexcept function fclose() that is called from a destructor without a try-catch statement (correctly so because fclose is declared noexcept). If fclose() is now allowed to throw when its preconditions fail, that will cause the destructor ~x() to throw as well?! void fclose(file& f) noexcept [[requires: f.is_open()]] ... class x { ~x() noexcept { fclose(f_); // f_ might not be open because of some bug... ... } file f_; }; (A point similar to the above is also made in N4160, in contrast with what argued in N4110.) Functions should honor their exception specifications (noexcept, etc.) even when their contracts fail and contract failure handlers are configured to throw. That is what Boost.Contract does (given that contract checking code appears within the function definition so it is subject to the exception specifications that appear in the enclosing function declaration): void fclose(file& f) noexcept { // This will call terminate()... boost::contract::guard c = boost::contract::function() .precondition([&] { BOOST_CONTRACT_ASSERT(f.is_open()); // ...even if this throws. } ; ... } int main() { boost::contract::set_precondition_failure( [] (boost::contract::from where) { // Re-throw exceptions (assertion_failure, user-defined, etc.). if(where != boost::contract::from_destructor) throw; std::terminate(); // But destructors never throw. } ); ... } Also note that a contract framework that allows to install failure handlers that throw exceptions should also pass some sort of parameter to the handler function to indicate if the contract failure happened in a destructor or not. That is so the failure handlers can choose to never throw for destructors, not even if class invariants (or postconditions) fails when checked by destructors. --Lorenzo

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[release] Continuous release archives.
by Rene Rivera 09 Aug '16

09 Aug '16

Starting with this release the archives for the prospective beta and release candidates are continuously built from the master branch and uploaded to SourceForge [1] (and to Bintray [2]). The release team would really appreciate if authors would download the archives and check the contents. In particular that the archives contain all the content you expect of your library, or libraries. And if you can also try building in your system that would stupendous. The more eyes we have on the final release products the smoother the process will be. And result in more time that the master branch is not blocked. Please report any problems sooner rather than later. So that we can try and address them before it's took late. Thank you, The Release Team [1] <https://sourceforge.net/projects/boost/files/boost/snapshots/master/> [2] <https://bintray.com/boostorg/master/snapshot#files> -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net -- rrivera/acm.org (msn) - grafikrobot/aim,yahoo,skype,efnet,gmail

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Feature suggestions for Boost's program_options
by Eyal Rozenberg 09 Aug '16

09 Aug '16

Greetings Boost developers, [ Disclaimer: I'm new to this list - I joined by Vladimir Prus' suggestion that I raise my feature ideas here on the list. I've read the posting guidelines, and I haven't seen any discussion of program_options (at least not by Vladimir himself) for at least a year back in the list archives, so I think my post is legit. ] I've been using Boost's program_options library for several months now. It mostly does the job (that's a compliment...) - but there are some features whose lack is really bugging me. For some of them (especially Feature Idea 1) I actually work around by taking some options as unparsed remainders, sticking them in a string->string map and parsing them myself. Without further ado, and in decreasing order of importance to me: -------------------------------- Feature Idea 1: Support specifying multiple alternative long option names, using comma-separation. Right now we can specify, for example, "include-path,I" - one short form, one long form. Why not allow specifying "include-path,include-dir,headers-path,I" ? Only the first long option name would be printed as part of the usage information, to not complicate things overmuch, and merely tolerate alternative phrasing. Feature Idea 2: Have a (new?) parser which supports taking "semi-parsed command-line options" as input: A map from string keys to string values, or to optional<string> values to represent options without an argument as well. This is actually very close to environment parsing, except that the environment parser gets its "map" from, well, the environment variables. So the implementation might be simply exposing the existing functionality with a slightly richer interface. Feature Idea 3: A facility for pretty-printing parsed options to an std::ostream, in which the option description starts the line, and the option value (not the name used for parsing) is printed after it. There is some pretty-printing for the usage info to the console, so why not this? (Argument against this idea: Choosing a default is a very touchy subject. Counter-argument: ... but that's also somewhat true of printing usage information; and nobody has to use this default, it would be entirely optional.) Feature Idea 4: Support three rather than just two levels of describing options: name, for the command line; short description, for listing values (see Feature Idea 3; long description for the usage info. Feature Idea 5: Create a variant of update_with which doesn't just set the option value, but creates a link of sorts between the variable which the app would use and the variable_map entry. With this in place, further changes to the variable map automagically affect the app variable. -------------------------------- So, - What do you think about these suggestions, in principle? - If you find some of them relevant, can you help estimate the necessary development effort and possible negative implications/caveats to consider? - Assuming a feature idea is both relevant and feasible, is it customary to request implementation by the maintainer? Commit yourself to implementing it vis-a-vis statement of statement of partiality to accepting a patch? Some other practice? Thank you for getting through the long(ish) email and for your hard work, Eyal Rozenberg DB architecture group CWI Amsterdam

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[release] Boost 1.62 closing for new libraries this week
by Rene Rivera 07 Aug '16

07 Aug '16

Hopefully everyone has had a good Summer and has gotten all the new libraries and breaking changes in.. As we are closing the release window for that this week. Please consult the calendar [1] for the full release schedule. And take this as a reminder to merge your changes that you want in the next release as soon as possible. [1] <http://www.boost.org/development/index.html> -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net -- rrivera/acm.org (msn) - grafikrobot/aim,yahoo,skype,efnet,gmail

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[boost-process] Beta & Review
by Klemens Morgenstern 07 Aug '16

07 Aug '16

Hi, boost-process is now in beta, you can check it out here: https://github.com/klemens-morgenstern/boost-process and read the doc here: http://klemens-morgenstern.github.io/process/ It will probably be in review in the beginning of November, Antony Polukhin will be the review manager. I really hope I'll get some feedback before that, so I can work on the weak points and also get more detailed in the documentation. Thanks, Klemens

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[boost-spirit-qi] Support for n-ary operators PR
by Frank Hein 06 Aug '16

06 Aug '16

Hello, some days ago I raised an PR (https://github.com/boostorg/spirit/pull/200) which adds support for a new class of parsers, in particular named n-ary operators. Joel de Guzman reviewed that. The code is ok. Because this addition touches the inner core of qi, the metagrammar, Joel asked me to drum for support in the community. So if you are in qi, may I kindly ask you to review this PR, the code, the discussion so far, and respond, if you want to support this PR or if you think, it's not needed. Thank you very much. I highly appreciate your feedback. The PR description is very detailled, so this mail has not to be. :) Regards, Frank

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Review Schedule and Review Manager for PODs Flat Reflection (ex magic_get)
by Antony Polukhin 05 Aug '16

05 Aug '16

Hello, PODs Flat Reflection (or PFR) is a C++14 library that represents POD structures as tuples and provides tuple-like methods for PODs. Library has a set of predefined operators for PODs and useful functions for everyday use. Works with user-defined types without any macro or boilerplate code. Library: https://github.com/apolukhin/magic_get Docs: http://apolukhin.github.io/magic_get/ Boost Library Incubator: http://blincubator.com/bi_library/pfr-pod-flat-reflection/?gform_post_id=16… Could the PODs Flat Reflection library be put on review schedule? Anyone wishing to become a Review Manager for the library? -- Best regards, Antony Polukhin

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[config] RFC PR 82
by Domagoj Saric 01 Aug '16

01 Aug '16

Hi everyone, I am finally getting back to (trying to) contributing some of my personal projects to Boost. For two of those, Err (https://github.com/psiha/err) and especially Functonoid (a C++11 generalization and rewrite of my previous Boost.Function related work) I need some lower level codegen and/or optimiser control functionality (i.e. portable macros wrapping toolset specific attributes and pragmas) that I've added to my personal fork of Boost.Config and which I've now submitted in the subject PR (https://github.com/boostorg/config/pull/82) I don't expect this PR to be accepted as is/'just like that' so I'm opening this thread where we can discuss which of those changes/macros are welcome, which need more work and which, for some reason, should not be part of Boost.Config (and which, in turn then, I have to move to some 'internal implementation headers' in libraries that will need them). To avoid 'spamming' (and save time;) I'll skip the explanation of the individual macros as I expect them to mostly be self-explanatory (if not from their name then from the minimal Boost.Config documentation additions that are part of th PR). ps. I'll be on the (off) road for the next three weeks so I don't know when I'll be able to respond until I get back... -- "What Huxley teaches is that in the age of advanced technology, spiritual devastation is more likely to come from an enemy with a smiling face than from one whose countenance exudes suspicion and hate." Neil Postman

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constexpr, cmath functions and other functions and distributions
by Paul A. Bristow 01 Aug '16

01 Aug '16

After much head scratching (and some head banging) - against a string of "Computer Says No" inscrutable diagnostic messages. I believe that I have now produced a (partial) version of Boost.Math normal_distribution that can be a constexpr using GCC6.1.1. (diagnosis has got to improve if constexprizing existing code is to become popular? ) constexpr normal_distribution<double> n01(0., 1.); producing this code 960 .loc 1 47 0 961 000d 660FEFC0 pxor %xmm0, %xmm0 # tmp89 962 0011 F20F1145 movsd %xmm0, -32(%rbp) # tmp89, n01.m_mean 962 E0 963 0016 F20F1005 movsd .LC1(%rip), %xmm0 #, tmp90 963 80080000 964 001e F20F1145 movsd %xmm0, -24(%rbp) # tmp90, n01.m_sd 964 E8 and more interestingly, a PDF can be calculated at compile-time constexpr double p = pdf(n01, 0.5); 965 .loc 1 56 0 966 0023 F20F1005 movsd .LC2(%rip), %xmm0 #, tmp91 966 88080000 967 002b F20F1145 movsd %xmm0, -8(%rbp) # tmp91, p 967 F8 Perhaps the assembler whizzes can confirm that this looks like a compile-time computation? This relies on lots of C++14 and 17 constexpr features, and Most crucially it relies on being able to use several cmath functions as constexpr. For a couple of trivially simple examples: abs(x) and isfinite(x). constexpr double ax42 = abs(-42.); // Unspecified version of abs. constexpr double ax42g = ::abs(-42.); // C double version? constexpr double ax42b = __builtin_abs(-42.); // builtin GCC only constexpr double ax42s = std::abs(-42.); // std:: version Without most cmath functions it seems to me impossible to write any reasonable (so-called special or not) mathy function or statistical distribution that can be constexpr. At present, only GCC 6.1.1 authors have foreseen this need and provided these so-called built_in_* cmath function versions that are constexpr, see https://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html. (Aside on other compilers: · Clang 3.8 has some problem deep inside type_traits that I haven't yet investigated. · VS2015 update 3 still doesn't compile many essential C++17 features from my experiments so far, and doesn't provide any constexpr cmath functions. ) The many potential benefits of compiler-time computations are quite enticing to contemplate :-) * No run-time where possible * Errors caught at compile-time * Improved code readability * Reduce executable footprint and potentially most important * Avoid global initialization order issues * Avoid initialization thread races See · Scott Schurr, C++ Developer, Ripple Labs https://cppnow2015.sched.org/event/2oLK/constexpr-c-at-compile-time · Dietmar Khul Constant Fun https://www.youtube.com/watch?list=PL9hrFapz4dsM1B9bI8VmEE4JJlR0m-dvo <https://www.youtube.com/watch?list=PL9hrFapz4dsM1B9bI8VmEE4JJlR0m-dvo&v=T37…> &v=T37ElKPICvo&app=desktop Is there any support for making std::abs and friends constexpr where possible in future versions of the C++ Standard? Paul PS I can't conceive of any UDT using or providing floating-point without some function like frexp to get and set exponent and significand. I also note that making constexpr frexp and ldexp and other functions passing a pointer to a variable to be updated may be more difficult/impossible, and is very likely to require at least initialization of the to-be-updated variable before calling frexp. I've investigated overcoming this by writing a naïve new constexpr version of frexp returning a std::pair (significand and exponent) but, of course, it can never be a 'drop-in' replacement because it has a different signature, so lots of code changes are inevitable. --- Paul A. Bristow Prizet Farmhouse Kendal UK LA8 8AB +44 (0) 1539 561830

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[type_erasure] Do we have a maintainer (minor fix needed)?
by John Maddock 31 Jul '16

31 Jul '16

This trivial PR is open for type_erasure and fixes an issue introduced by changes to Boost.Config (enabling constexpr support for VC14up3). https://github.com/boostorg/type_erasure/pull/11 BTW the failure is not caused by buggy constexpr support, there's some other issue going on once that code path is enabled. Anyhow, since we really should be merging Config to master soon, I'd like to see this collateral-damage fixed if possible. Thanks, John.

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[contract] Template types
by Lorenzo Caminiti 29 Jul '16

29 Jul '16

Hello all, I would like to discuss the extra type requirements that contracts can impose of generic types and how Boost.Contract handles that. I think I mentioned some of this already in different emails to this list, but I wanted to summarize this topic in one email. For example, note that the following code will not compile when the old value template parameter T is not copyable: template<typename T> void swap(T& a, T& b) [[ensures: a == old(b)]] ... In Boost.Contract (approach 1): template<typename T> void swap(T& a, T& b) { boost::contract::old_ptr<T> old_b = BOOST_CONTRACT_OLDOF(b); boost::contract::guard c = boost::contract::function() .postcondition([&] { BOOST_CONTRACT_ASSERT(a == *old_b); }) ; ... } In some cases, that might be what the contract writers want: the generic old value type T is not copyable so postconditions cannot be checked and the program should not compile. However, in some other cases the contract writes might not want to add the extra copyable requirement on T and check the related postconditions only when callers specify a template parameter T that happens to be copyable. That can be done allowing some sort of static-if in contracts: template<typename T> void swap(T& a, T& b) [[ensures: static if(is_copyable<T>::value) a == old(b)]] ... In Boost.Contract (approach 2): template<typename T> void swap(T& a, T& b) { boost::contract::old_ptr_if_copyable<T> old_b = BOOST_CONTRACT_OLDOF(b); boost::contract::guard c = boost::contract::function() .postcondition([&] { if(old_b) BOOST_CONTRACT_ASSERT(a == *old_b); }) ; ... } Both approach 1 and 2 above are valid and should be supported by the framework. The decision between which approach to use for a specific contract should be left up to the programmers. Like old values can introduce the extra copyable type requirement, any contract assertion can in general introduce an number of extra requirements on generic types, namely the type requirements necessary to support the operations used to program the contract assertions. For example, the following code will not compile if T is not equality comparable (which is not a type requirement vector normally imposes on T): template<typename T> class vector { void push_back(T const& value) [[ensures: back() == value]] ... }; In Boost.Contract (approach 1): template<typename T> class vector { void push_back(T const& value) { boost::contract::guard c = boost::contract::public_function(this) .postcondition([&] { BOOST_CONTRACT_ASSERT(back() == value); }) ; ... } }; Again, that might be what contract writes want in some case but in other cases they might want to just skip the assertion when T does not meet all the type requirements needed by the operations used in the assertion: template<typename T> class vector { void push_back(T const& value) [[ensures: static if(has_equal_to<T>::value) back() == value]] ... }; In Boost.Contract (approach 2): template<typename T> class vector { void push_back(T const& value) { boost::contract::guard c = boost::contract::public_function(this) .postcondition([&] { BOOST_CONTRACT_ASSERT( boost::contract::check_if<has_equal_to<T>::value >( boost::bind(equal_to<T>, cref(back()), cref(value)) ) ); }) ; ... } }; --Lorenzo

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Gmane going away
by Tom Kent 29 Jul '16

29 Jul '16

So it looks like Gmane is under attack and the guy who runs it is thinking about just turning it off (that would be sad). https://lars.ingebrigtsen.no/2016/07/28/the-end-of-gmane/ Anyway, I know a lot of boost users use is as the gnu mailman archive pages are really hard to use. I would like to propose that we (specifically the list owner(s)) mirror the boost mailing lists to the mail-archive.com site. It has good search features and decent thread browse-ability. Thoughts? Tom

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Boost Social Event at CppCon 2016
by Jon Kalb 28 Jul '16

28 Jul '16

Boost Developers, Because a lot of Boosters are going to be attending CppCon, we¹d like to arrange a social event for Boosters/C++Now attendees. 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 17th and 23rd 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 If you are attending, please make your hotel reservations soon. We are likely to sell out of our room block. http://cppcon.org/lodging/ I hope to see you at CppCon. Jon

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Approximate matching to Boost.Algorithm
by Зайцев Александр 27 Jul '16

27 Jul '16

Hello. I want to discuss about some proposals. I am working on Levenshtein distance and Damerau-Levenshtein distance algortihms. I hope, that these implementations will be pulled to the Boost String library. But i think that we can add to the Boost String Library some more algorithms for fuzzy searhing. You can find this list here: https://fuzzystring.codeplex.com/ List: 1)Hamming Distance 2)Jaccard Distance 3)Jaro Distance 4)Jaro-Winkler Distance 5)Levenshtein Distance 6)Longest Common Subsequence 7)Longest Common Substring 8)Overlap Coefficient 9)Ratcliff-Obershelp Similarity 10)Sorensen-Dice Distance 11)Tanimoto Coefficient Maybe something else... What do you think about this idea? If you think that it can be implemented to the Boost String Algo, i will start work on this list immediately. Best regards, Zaitsev Alexander.

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I am working on Aho-Corasik
by Зайцев Александр 27 Jul '16

27 Jul '16

Hello. FYI: Now i am working on Aho-Corasik algorithm. Best regards, Alexander Zaitsev.

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Fast nth-elemnt on the segment
by Зайцев Александр 26 Jul '16

26 Jul '16

Hello. What do you think about algorithm of fast searching nth-elemnt on the segment with O(logN), where N is count of elements. I would implement it to Boost.Algorithm. Best regards, Alexander Zaitsev

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[type_erasure] Conflict with private member called data
by Nigel Pattinson 22 Jul '16

22 Jul '16

Hi I'm running into a problem with the type erasure library when trying to declare a member called 'data', e.g. BOOST_TYPE_ERASURE_MEMBER((has_data), data) using SomeClass = any< vector< copy_constructible<>, typeid_<>, relaxed, has_data<void*()> > >; This conflicts with the private member variable called 'data' in the any class. SomeClass does compile, but attempting to call the data() does not compile due to the conflict, with the error message being 'cannot access private member ... ' . I'm not sure if this is a limitation in the library or a compiler bug - I'm using Visual Studio 2015 Update 1. Using boost 1.57.0 at present, I could use a more recent version if that would help. Does anyone know of a possible workaround ? Thanks Nigel Pattinson

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Update for the Cxx dual library
by Edward Diener 22 Jul '16

22 Jul '16

The Cxx dual library, or CXXD for short, is a C++ macro header-only library which chooses between using a Boost library or its C++ standard equivalent library for a number of different C++ implementations, while using the same code to program either choice. An 'implementation', called a 'dual library', is a Boost library which has a C++ standard library equivalent whose public interfaces are nearly the same in both cases. I have updated the Cxx dual library, for those who prefer to minimize their use of macros in source code, by providing an alternate method to the use of macros for including the appropriate header files and specifying the appropriate namespace for a dual library. In this alternate method including the appropriate header files is done by including an implementation header file, and specifying the appropriate namespace is done by using a C++ namespace alias. The alternate method, called the alias mode, is fully documented. You can get the latest version of the Cxx dual library at https://github.com/eldiener/cxx_dual. Instructions for using the library are in the README.md file. PDF documentation is available in cxx_dual.pdf, HTML doc is availavble online at http://eldiener.github.io/cxx_dual and you can generate local HTML documentation using the doc jam file. Questions, comments, bug reports are always welcome.

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does boost support multimedia framework
by qw 22 Jul '16

22 Jul '16

Hi, Does boost support multimedia framework, just like gstreamer? Thanks! Regards Andrew

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[contract] Class invariants (also for static and volatile/const-volatile public functions)
by Lorenzo Caminiti 21 Jul '16

21 Jul '16

Hello all, I would like to discuss class invariants, but also for static and volatile/const-volatile public member functions, and specifically with respect to how Boost.Contract handles them. Class invariants are important... almost as important as preconditions. For example for a vector container, class invariants specify among other things the equivalence relationship `(size() == 0) == empty()` that could be found useful by static analyzers and optimizes (also discussed in N4160): template<typename T> class vector { [[invariant: (size() == 0) == empty()]] [[invariant: size() <= capacity()]] public: void push_back(T const& value) ... { ... } }; The above contract cannot be programmed using preconditions and postconditions unless: it is repeated (together with all other invariant assertions) in pre- and postconditions of each public member functions, it is asserted with try-catches also when those functions throw, it is repeated in constructor postconditions, in destructor preconditions, and with try-catches also when destructors throw... Even if invariants are programmed in some `bool invariant() const` function to avoid repeating all invariant assertions in each pre- and postcondition, the code will be cluttered by boiler-plate code (try-catch to assert invariants on throw, etc.) and an invariant failure will just report that the invariant() function returned false, but it will not report which specific invariant condition actually failed (plus static analyzers and optimizes will not be able to parse the conditions from the invariant function): template<typename T> class vector { bool invariant() const { // But cannot distinguish which of the two assertions failed... // and cannot be used by static analyzers and optimizers. return (size() == 0) == empty() && size() <= capacity(); } public: void push_back(T const& value) ... [[requires: invariant()]] [[ensures: invariant()]] { try { ... } catch(...) { [[assert: invariant()]]; throw } } }; Class invariants cannot be effectively emulated using pre- and postconditions... they should be added to a contract framework as their own feature. In Boost.Contract: template<typename T> class vector { void invariant() const { BOOST_CONTRACT_ASSERT((size() == 0) == empty()); BOOST_CONTRACT_ASSERT(size() <= capacity()); } public: void push_back(T const& value) { boost::contract::guard c = boost::contract::public_function(*this) ... ; ... } }; Note that the above invariant function `void invariant() const` cannot be declared static or const-volatile because it will need to call queries like size(), empty(), capacity(), etc. that are const and not static or const-volatile. Thus the above invariant function, being const, cannot be called at entry and exit of static and volatile/const-volatile public functions. A contract framework for C++ should support also static and const-volatile class invariants to properly handle static and volatile/const-volatile public functions (even if static and const-volatile class invariants are not mentioned in any C++ contract proposal): * Static public functions check static class invariants at entry, at exit, and if body throws. * Volatile and const-volatile public functions check static and const-volatile class invariants (in that order) at entry, at exit, and if body throws. * Non cv-qualified and const public functions check static, const-volatile, and const class invariants (in that order) at entry, at exit, and if body throws. * Constructors check static class invariants at entry, at exit, and if body throws (because those do not require the object to be constructed). Then constructors check const-volatile and const class invariants (in that order) at exit (if body does not throw, because those require the object to be constructed). * Destructors check static class invariants at entry, at exit, and if body throws (because those do not require a constructed object). Then destructors check const-volatile and const class invariants (in that order) at entry and if body throws (because those require a constructed object). In Boost.Contract: struct a { static void static_invariant() { BOOST_CONTRACT_ASSERT(...); } void invariant() const volatile { BOOST_CONTRACT_ASSERT(...); } void invariant() const { BOOST_CONTRACT_ASSERT(...); } // Following check all static_invariant(), invariant() const volatile, and invariant() const (in that order). a() { boost::contract::guard c= boost::contract::constructor(this); } virtual ~a() { boost::contract::guard c = boost::contract::destructor(this); } void m() /* no cv qualifiers */ { boost::contract::guard c = boost::contract::public_function(*this); } void c() const { boost::contract::guard c = boost::contract::public_function(*this); } // Following check both static_invariant() and invariant() const volatile (in that order). void v() volatile { boost::contract::guard c = boost::contract::public_function(*this); } void cv() const volatile { boost::contract::guard c = boost::contract::public_function(*this); } // Following check only static_invariant(). static void s() { boost::contract::guard c = boost::contract::public_function<a>(); } }; Maybe volatile member functions are rarely used in C++ so const-volatile class invariants will also be used rarely if at all... Nevertheless, if const-volatile class invariants are not supported, it will not be possible to specify invariants for classes with volatile public functions so const-volatile class invariants should be supported for completeness. Static class invariant could instead be useful when programming contracts for the static part of the object state. In particular, Boost.Contract also supports postconditions for destructors (those should be checked by a static function because they should not access the object `this` that has been destroyed after the execution of the destructor body). Destructor postconditions are not mentioned in any contract proposal... but together with constructor and other function pre- and postconditions, and together with static class invariants, they can specify contracts for the static part of the object state. For example, consider the contracts for a class that counts the number of its object instances: struct a : private noncopyable, private nonmovable { static void static_invariant() { BOOST_CONTRACT_ASSERT((instances() != 0) == exists()); } a() { boost::contract::old_ptr<unsigned> old_instances = BOOST_CONTRACT_OLDOF(instances()); boost::contract::guard c = boost::contract::constructor(this) .postcondition([&] { BOOST_CONTRACT_ASSERT(instances() == old_instances + 1); }) ; ++instances_; } virtual ~a() { boost::contract::old_ptr<unsigned> old_instances = BOOST_CONTRACT_OLDOF(instances()); boost::contract::guard c = boost::contract::destructor(this) .postcondition([&] { // Must never use object `this`. BOOST_CONTRACT_ASSERT(instances() == old_instances - 1); }) ; --instances_; } static unsigned instances() { boost::contract::guard c = boost::contract::public_function<a>(); return instances_; } static bool exists() { boost::contract::guard c = boost::contract::public_function<a>(); return instances_ != 0; } private: static unsigned instances_; }; unsigned a::instances_ = 0; --Lorenzo

1 0

double_ended - request formal review
by Benedek Thaler 21 Jul '16

21 Jul '16

Dear Boost, I'd like to request the review of the double_ended library. Code: https://github.com/erenon/double_ended Documentation: http://erenon.hu/double_ended The library contains two classes. Excerpt from the documentation: * `devector` is a hybrid of the standard vector and deque containers, as well as the small_vector of Boost.Container. It offers cheap (amortized constant time) insertion at both the front and back ends, while also providing the regular features of std::vector, in particular the contiguous underlying memory. In contrast to the standard vector, however, devector offers greater control over its internals. Like small_vector, it can store elements internally without dynamically allocating memory. * `batch_deque` is very similar to the standard deque, with a slight twist. It lets you specify its segment size: The size of the contiguous memory segments it uses to store its elements. This provides a consistent layout across platforms, and lets you iterate over the segments with batch operations. I'm also looking for a review manager. Thanks, Benedek

2 1

[contract] Friend functions
by Lorenzo Caminiti 19 Jul '16

19 Jul '16

Hello all, I would like to discuss contracts for friend functions and specifically how they are handled in Boost.Contract. Consider the following example: class a; class b; class data { ... friend bool deep_equal(a*, b*); bool equal(data const&); }; class a { ... friend bool deep_equal(a*, b*); data data_; }; class b { ... friend bool deep_equal(a*, b*); data data_; }; bool deep_equal(a* x, b* y) { return x->data_.equal(y->data_); } Via friendship, deep_equal can be considered to extend a and b public interfaces, but not data's public interface (in fact, deep_equal does not take instance of data as an argument). Therefore, it is reasonable to think that deep_equal should check a and b class invariants (if so... in which order?), but not data's class invariants. As discussed in N4160, that would probably require some new language feature to specify which subset of friend functions also extend a class public interface. Plus such a feature should identify some preferred order in which class invariants should be checked for a friend function that extends public interfaces of multiple classes. That seems rather complicated so I think a language proposal (like N1962) is better off going with the general rule that friends functions do not check class invariants (even if that might not always be ideal in all cases): bool deep_equal(a* x, b* y) [[requires: x && y]] // Does not check a and b (and c) invariants... even if arguably it should. { return x->data_.equal(y->data_); } In Boost.Contract: bool deep_equal(a* x, b* y) { boost::contract::guard c = boost::contract::function() .precondition([&] { BOOST_CONTRACT_ASSERT(x && y); }) ; // Does not check a and b (and c) invariants... even if arguably it should. return x->data_.equal(y->data_); } Maybe programmers could manually check a and b invariants (but then also from the function body when it throws) when those checks are truly essential for friend function: bool deep_equal(a* x, b* x) [[requires: x && y]] // Check a and b invariants in that order (if contract writes decide to), does not check c invariants. [[requires: x->invariant() && y->invariant()] [[ensures: x->invariant() && y->invariant()] { try { return x->data_.equal(y->data_); } catch(...) { [[assert: x->invariant() && y->invariant()]]; throw; } } (That seems somewhat verbose... plus it assumes that class invariants are somehow specified in a `bool invariant() const function (that can be private), or using a set of [[invariant: ...]] attributes that automatically generate such a callable `bool invariant() const` function.) This is possible in Boost.Contract: bool deep_equal(a* x, b* y) { boost::contract::guard c = boost::contract::function() .precondition([&] { BOOST_CONTRACT_ASSERT(x && y); }) ; // Check a and b invariants in that order (if contract writers decide to), does not check c invariants. boost::contract::guard inv_x = boost::contract::public_function(*x); boost::contract::guard inv_y = boost::contract::public_function(*y); return x->data_.equal(y->data_); } Finally, note that in this case preconditions are checked before entry invariants (while usually public functions check preconditions after entry invariants). That is desirable/needed for friend functions because the class object is not *this (which is always well defined and therefore subject to no precondition). For friend functions, the class object can be any computation of the friend function arguments and those arguments must be validated by preconditions before they can be used to access the class object. In the examples above, the arguments are checked to be not null by preconditions so they can be safely dereferenced to get the objects *x and *y (and in general the computations required might be even much more complex than dereferencing pointers). Thank you. --Lorenzo

1 0

[contract] Without the macros
by Lorenzo Caminiti 19 Jul '16

19 Jul '16

Hello all, In the last few years my professional and personal lives changed quite a bit limiting my ability to contribute to Boost. However, in my spare time I slowing continued to revise Boost.Contract hoping to be able to commit it to a Boost release someday (after the library was accepted 3+ years ago... https://groups.google.com/forum/?fromgroups=#!topic/boost-list/jQ7OjAmos_Y) While doing so I realized that leveraging C++11 lambda functions, Boost.Contract could be re-implemented without its crazy macros that alter C++ function declaration syntax. Boost.Contract still remains the only C++ library that implements *all* features of Contract Programming (a.k.a., Design by Contract or DbC): subcontracting, class invariants (also static and volatile), postconditions (with old and return values), preconditions, customizable actions on assertion failure (terminate, throw, etc.), optional assertion compilation, disable assertion checking while already checking other assertions (to avoid infinite recursion), etc. Furthermore, in its new incarnation Boost.Contract no longer uses crazy macros so it is easier to use, faster to compile, and gives readable compiler errors. For example: #include <boost/contract.hpp> int inc(int& x) { int result; boost::contract::old_ptr<int> old_x = BOOST_CONTRACT_OLDOF(x); boost::contract::guard c = boost::contract::function() .precondition([&] { BOOST_CONTRACT_ASSERT(x < std::numeric_limits<int>::max()); }) .postcondition([&] { BOOST_CONTRACT_ASSERT(x == *old_x + 1); BOOST_CONTRACT_ASSERT(result == *old_x); }) ; return result = x++; // Function body. } Or with subcontracting: #include <boost/contract.hpp> #include <vector> template<typename T> class pushable; // Arbitrary base to demo subcontracting. template<typename T> class vector #define BASES public pushable<T> : BASES { public: typedef BOOST_CONTRACT_BASE_TYPES(BASES) base_types; // Subcontracting. #undef BASES void invariant() const { // Checked in AND with base class invariants. BOOST_CONTRACT_ASSERT(size() <= capacity()); // Line 25. } virtual void push_back(T const& value, boost::contract::virtual_* v = 0) /* override */ { boost::contract::old_ptr<unsigned> old_size = BOOST_CONTRACT_OLDOF(v, size()); // Old values. boost::contract::guard c = boost::contract::public_function< override_push_back>(v, &vector::push_back, this, value) .precondition([&] { // Checked in OR with base preconditions. BOOST_CONTRACT_ASSERT(size() < max_size()); // Line 35. }) .postcondition([&] { // Checked in AND with base postconditions. BOOST_CONTRACT_ASSERT(size() == *old_size + 1); // Line 38. }) ; vect_.push_back(value); // Function body. } BOOST_CONTRACT_OVERRIDE(push_back) // For `override_push_back`. // Could program contracts for those as well. unsigned size() const { return vect_.size(); } unsigned max_size() const { return vect_.max_size(); } unsigned capacity() const { return vect_.capacity(); } private: std::vector<T> vect_; }; Full documentation and examples at: https://lcaminiti.github.io/boost-contract What do you think? Thanks, --Lorenzo P.S. The library can also be used without C++11 lambda functions (or any C++11 specific feature) but programmers have to write a fare amount of extra code to program the precondition and postcondition functors (using non-local functions, Boost.LocalFunction, Boost.Funsion, Boost.Lambda, or some other approach) so that might not useful in practice.

6 14

[graph] Compilation error with adjacency_list and C++11
by Sebastien Loriot (GeometryFactory) 18 Jul '16

18 Jul '16

Hello, the program below does not compile at least with g++ 5.3.1 and clang++ 3.5.2-1 when using c++11 standard. If I comment line #1 it compiles. If I change #2 to undirectedS it compiles. Is there anything wrong in my code or is it a problem in boost's? Thanks, Sebastien. #include <boost/graph/adjacency_list.hpp> struct A { A(){} A(const A& ){} // #1 A& operator=(const A&){return *this;} }; typedef boost::adjacency_list<boost::listS, boost::vecS, boost::directedS, //#2 A > Graph; int main() { Graph g; boost::add_vertex(g); return 0; }

2 2

[type_index] Interest in dynamic_cast emulation?
by Chris Glover 17 Jul '16

17 Jul '16

Hi, I reached for Boost.TypeIndex the other day expecting to find a kind of dynamic_cast I could use in the absence of Rtti. I didn't find it, so I wrote something to emulate it using type_index internally. It's working, but before I go too far and clean this up and possibly submit a pull request, I would like to gauge if there's interest in such a thing or if there's some fundamental reason why it doesn't exist. So, thoughts? Thanks, -- chris

5 8

[contract] Strong exception safety guarantees
by Lorenzo Caminiti 15 Jul '16

15 Jul '16

Hello all, I've been considering adding a .except(...) construct to Boost.Contract that will allow to specify conditions to check at function exit but when the function body throws (in contrast to postconditions that are checked at function exit but only when the function body does not throw). I think .except(...) could be used to assert strong exception safety guarantees... (note that class invariants are already checked at exit of public functions and also when the public function bodies throw, but invariants are suited to assert only basic, and not strong, exception safety guarantees). That might help addressing a point made in P0147R0 under the "Contracts and Exceptions" section: ``Some operations make stronger exception safety claims. In particular, they claim that an exception thrown from a member function will leave the state of an object unchanged from its state on function entry. If we invalidate postconditions on exceptions, we appear to have no mechanism to describe strong exception safety.'' For example, the following swap ensures to leave its arguments unchanged when it throws: void swap(std::string& a, std::string& b) { boost::contract::old_ptr<std::string> old_a = BOOST_CONTRACT_OLDOF(a); boost::contract::old_ptr<std::string> old_b = BOOST_CONTRACT_OLDOF(b); boost::contract::guard c = boost::contract::function() .postcondition([&] { // Checked at function exit but only if body does not throw. BOOST_CONTRACT_ASSERT(a == *old_b); BOOST_CONTRACT_ASSERT(b == *old_a); }) .except([&] { // Checked if body throws (strong exception safety guarantees). BOOST_CONTRACT_ASSERT(a == *old_a); BOOST_CONTRACT_ASSERT(b == *old_b); }) ; ... // Body implementation (which might throw). } Would this be beneficial? Thanks, --Lorenzo

2 5

smartptr maintained
by Karolin Varner 15 Jul '16

15 Jul '16

Hi, is smartptr still being maintained? There are four pull requests, one more than a year old. Best, Karolin Varner

2 3

[graph] A* implementation doesn't follow the algorithm
by Nick Lamprianidis 14 Jul '16

14 Jul '16

For the A* algorithm holds that when a new vertex v is reached through a shorter path, then v is added to the open set. But looking at the boost graph's A* implementation, which is based on the BFS algorithm, one can see that a target vertex is added to the priority queue, regardless of whether the relevant edge is being relaxed. This creates the following situation: The execution starts and you get to a point where you know you cannot reach the goal: no vertices with finite cost in the priority queue. Normally, you would expect that the priority queue is empty and thus the execution ends. Instead, the execution continues, since the priority queue is filled with all those vertices (with infinite cost) that got added for no reason. In an application where the state of a target vertex v gets set when an associated edge is being relaxed, a problem arises. In the situation mentioned above, uninitialized vertices reach the visitor's examine_vertex method. Unless you know what's really happening, so you can take care to add a test condition to exit, it leaves you wondering what's going wrong. I propose that you either change the implementation or at least update the documentation (pseudocode). -- Nick Lamprianidis http://paign10.me

3 2

[log][regression] Error with Boost.Lob build jamfile breaks MinGW regression tester in develop
by Ion Gaztañaga 13 Jul '16

13 Jul '16

Hi, My develop branch regression runner fails whereas the master one works fine. The develop runner fails with all Mingw targets (msvc 7.1 works fine), with this error: ************************************ # Starting tests ("c:\boost\develop\boost_bb\src\engine\bin.ntx86\bjam.exe" "-sBOOST_BUILD_PATH=c:\boost\develop;c:\boost\develop\boost_bb\src" "-sBOOST_ROOT=c:\boost\develop\boost_root" "--boost=c:\boost\develop\boost_root" "--boost-root=c:\boost\develop\boost_root" "--boost-build=c:\boost\develop\boost_bb\src" "--debug-configuration" -l300 toolset=gcc-6.1c++14 -d2 preserve-test-targets=off --dump-tests -j3 --abbreviate-paths debug-symbols=off -m64 "--build-dir=c:\boost\develop\results" >>"c:\boost\develop\results\bjam.log" 2>&1)... c:\boost\develop\boost_root\status> "c:\boost\develop\boost_bb\src\engine\bin.ntx86\bjam.exe" "-sBOOST_BUILD_PATH=c:\boost\develop;c:\boost\develop\boost_bb\src" "-sBOOST_ROOT=c:\boost\develop\boost_root" "--boost=c:\boost\develop\boost_root" "--boost-root=c:\boost\develop\boost_root" "--boost-build=c:\boost\develop\boost_bb\src" "--debug-configuration" -l300 toolset=gcc-6.1c++14 -d2 preserve-test-targets=off --dump-tests -j3 --abbreviate-paths debug-symbols=off -m64 "--build-dir=c:\boost\develop\results" 1>>"c:\boost\develop\results\bjam.log" 2>&1 # Running Boost.Build tests Traceback (most recent call last): File "run.py", line 71, in <module> runner(root) File "c:\boost\develop\boost_regression_src\regression.py", line 287, in __init__ self.main() File "c:\boost\develop\boost_regression_src\regression.py", line 624, in main getattr(self,action_m)() File "c:\boost\develop\boost_regression_src\regression.py", line 589, in command_regression self.command_test() File "c:\boost\develop\boost_regression_src\regression.py", line 368, in command_test self.command_test_boost_build() File "c:\boost\develop\boost_regression_src\regression.py", line 410, in command_test_boost_build "boost/bin.v2/libs/any/test/any_test.test")); WindowsError: [Error 3] The system cannot find the path specified: 'c:\\boost\\develop\\results\\boost/bin.v2/libs/any/test/any_test.test/*.*' ************************************ That path ("..libs/any/test/any_test.test/) is hardcoded in regression.py, but it's not generated in my bin.v2 so it's reasonable an error saying that the system can't find the path ;-) It seems that error occurs before boost.build tests, as bjam.log shows: ************************************ C:/boost/develop/boost_bb/src/build\targets.jam:1077: in evaluate-requirements from module targets error: Can not evaluate conditional properties <conditional>@Jamfile<C:\boost\develop\boost_root>%Jamfile<C:\boost\develop\boost_root>.handle-static-runtime <conditional>@Jamfile<C:\boost\develop\boost_root>%boostcpp.deduce-address-model <conditional>@Jamfile<C:\boost\develop\boost_root>%boostcpp.deduce-architecture <conditional>@Jamfile<C:\boost\develop\boost_root\libs\log\build>%Jamfile<C:\boost\develop\boost_root\libs\log\build>.check-instruction-set <conditional>@Jamfile<C:\boost\develop\boost_root\libs\log\build>%Jamfile<C:\boost\develop\boost_root\libs\log\build>.check-message-compiler <conditional>@Jamfile<C:\boost\develop\boost_root\libs\log\build>%Jamfile<C:\boost\develop\boost_root\libs\log\build>.check-pthread-mutex-robust <conditional>@Jamfile<C:\boost\develop\boost_root\libs\log\build>%Jamfile<C:\boost\develop\boost_root\libs\log\build>.check-visibility <conditional>@Jamfile<C:\boost\develop\boost_root\libs\log\build>%Jamfile<C:\boost\develop\boost_root\libs\log\build>.select-arch-specific-sources <conditional>@Jamfile<C:\boost\develop\boost_root\libs\log\build>%Jamfile<C:\boost\develop\boost_root\libs\log\build>.select-platform-specific-sources <conditional>@Jamfile<C:\boost\develop\boost_root\libs\log\build>%Jamfile<C:\boost\develop\boost_root\libs\log\build>.select-regex-backend <link>shared:<define>BOOST_LOG_DLL <target-os>cygwin:<define>BOOST_USE_WINDOWS_H <target-os>cygwin:<define>NOMINMAX <target-os>cygwin:<define>SECURITY_WIN32 <target-os>cygwin:<define>WIN32_LEAN_AND_MEAN <target-os>cygwin:<define>__USE_W32_SOCKETS <target-os>cygwin:<library>/boost/log//advapi32 <target-os>cygwin:<library>/boost/log//mswsock <target-os>cygwin:<library>/boost/log//ws2_32 <target-os>freebsd:<library>/boost/log//rt <target-os>hpux:<define>_XOPEN_SOURCE=600 <target-os>hpux:<library>/boost/log//ipv6 <target-os>linux:<define>_XOPEN_SOURCE=600 <target-os>linux:<library>/boost/log//rt <target-os>qnxnto:<library>/boost/log//socket <target-os>solaris:<define>_XOPEN_SOURCE=500 <target-os>solaris:<define>__EXTENSIONS__ <target-os>solaris:<library>/boost/log//nsl <target-os>solaris:<library>/boost/log//socket <target-os>windows:<define>BOOST_USE_WINDOWS_H <target-os>windows:<define>NOMINMAX <target-os>windows:<define>SECURITY_WIN32 <target-os>windows:<define>WIN32_LEAN_AND_MEAN <target-os>windows:<library>/boost/log//advapi32 <target-os>windows:<library>/boost/log//mswsock <target-os>windows:<library>/boost/log//ws2_32 <threading>multi:<library>/boost/atomic//boost_atomic <threading>multi:<library>/boost/thread//boost_thread <threading>single:<define>BOOST_LOG_NO_THREADS <toolset>clang:<cxxflags>-ftemplate-depth-1024 <toolset>como-linux:<define>_GNU_SOURCE=1 <toolset>como:<link>static <toolset>darwin:<cxxflags>-ftemplate-depth-1024 <toolset>gcc,<target-os>cygwin:<linkflags>-Wl,--enable-auto-import <toolset>gcc,<target-os>windows:<linkflags>-Wl,--enable-auto-import <toolset>gcc:<cxxflags>-fno-strict-aliasing <toolset>gcc:<cxxflags>-ftemplate-depth-1024 <toolset>intel-darwin:<cxxflags>-wd177,780,2196,1782,193,304,981,1418,411,734,279 <toolset>intel-linux:<cxxflags>-wd177,780,2196,1782,193,304,981,1418,411,734,279 <toolset>intel-win:<cxxflags>/Qwd177,780,2196,1782,193,304,981,1418,411,734,279 <toolset>intel-win:<define>_CRT_SECURE_NO_DEPRECATE <toolset>intel-win:<define>_CRT_SECURE_NO_WARNINGS <toolset>intel-win:<define>_SCL_SECURE_NO_DEPRECATE <toolset>intel-win:<define>_SCL_SECURE_NO_WARNINGS <toolset>msvc,<runtime-link>shared:<threading>multi <toolset>msvc:<cxxflags>/bigobj <toolset>msvc:<cxxflags>/wd4003 <toolset>msvc:<cxxflags>/wd4456 <toolset>msvc:<cxxflags>/wd4459 <toolset>msvc:<cxxflags>/wd4503 <toolset>msvc:<define>_CRT_SECURE_NO_DEPRECATE <toolset>msvc:<define>_CRT_SECURE_NO_WARNINGS <toolset>msvc:<define>_SCL_SECURE_NO_DEPRECATE <toolset>msvc:<define>_SCL_SECURE_NO_WARNINGS <toolset>pgi:<library>/boost/log//rt C:/boost/develop/boost_bb/src/build\targets.jam:1112: in common-properties2 from module targets C:/boost/develop/boost_bb/src/build\targets.jam:977: in targets.common-properties from module targets C:/boost/develop/boost_bb/src/build\targets.jam:1303: in class(a)basic-target.generate from module object(typed-target)@1504 C:/boost/develop/boost_bb/src/build\targets.jam:774: in generate-really from module object(main-target)@49045 C:/boost/develop/boost_bb/src/build\targets.jam:746: in class(a)main-target.generate from module object(main-target)@49045 C:/boost/develop/boost_bb/src/build\targets.jam:895: in targets.generate-from-reference from module targets C:/boost/develop/boost_bb/src/build\targets.jam:1266: in generate-dependencies from module object(typed-target)@14269 C:/boost/develop/boost_bb/src/build\targets.jam:1320: in class(a)basic-target.generate from module object(typed-target)@14269 C:/boost/develop/boost_bb/src/build\targets.jam:774: in generate-really from module object(main-target)@49008 C:/boost/develop/boost_bb/src/build\targets.jam:746: in class(a)main-target.generate from module object(main-target)@49008 C:/boost/develop/boost_bb/src/build\targets.jam:895: in targets.generate-from-reference from module targets C:/boost/develop/boost_bb/src/build\targets.jam:1266: in generate-dependencies from module object(alias-target-class)@36618 C:/boost/develop/boost_bb/src/build\targets.jam:1323: in class(a)basic-target.generate from module object(alias-target-class)@36618 C:/boost/develop/boost_bb/src/build\targets.jam:774: in generate-really from module object(main-target)@36634 C:/boost/develop/boost_bb/src/build\targets.jam:746: in class(a)main-target.generate from module object(main-target)@36634 C:/boost/develop/boost_bb/src/build\targets.jam:272: in class(a)project-target.generate from module object(project-target)@2141 c:/boost/develop/boost_bb/src\build-system.jam:714: in load from module build-system C:\boost\develop\boost_bb\src/kernel\modules.jam:295: in import from module modules C:\boost\develop\boost_bb\src/kernel/bootstrap.jam:139: in boost-build from module C:\boost\develop\boost_root\boost-build.jam:17: in module scope from module ************************************ I can't see why this Jamfile from Boost.Log is accepted when MSVC-7.1 is the target but fails when MinGW is the selected target. I could neither t deduce what is the failing piece of the configuration. The same error happens with a wide range of MINGW targets: GCC-3.4, GCC-4.1, GCC-4.2, GCC-4.3, GCC-4.4, GCC-4.5, GCC-4.6, GCC-4.7, GCC-4.8, GCC-4.9, GCC-5.1, GCC-5.2, GCC-5.3 and GCC-6.1. Any clue on what can be happening and how can it be fixed? Attached regression logs for a failed MINGW regression with GCC 6.1. Best, Ion

3 8

[regression][winapi] Tests not being run
by Andrey Semashev 11 Jul '16

11 Jul '16

Hi, I wrote about it before, but now the problem becomes more weird. The problem is that the tests for Boost.WinAPI are not being run for some reason. What's weird is that now there is one test in the matrix (http://www.boost.org/development/tests/develop/developer/winapi.html) that isn't part of the Boost.WinAPI test suite. I assume that entry is part of the formal checks for the library conformance, since it is present for all libraries. Could someone please have a look why the tests for Boost.WinAPI are not being executed? PS: The link for the __boost_check_library__ entry is broken: https://github.com/boostorg/winapi/blob/developstatus/boost_check_library.py I believe, there's a slash missing between develop and status, and also the repository name should be boost rather than winapi.

2 2

[TypeErasure] Merging pull-requests
by Deniz Bahadir 11 Jul '16

11 Jul '16

Hello everyone, Hello Steven, a view weeks ago I reported some bugs of Boost.TypeErasure [1,2] and provided pull-requests [3,4] which fix these. I just wanted to bring these to attention so that they might get merged and find their way into the next Boost release. Thanks, Deniz PS: There is another open pull-request [5] (by John Maddock) which seems to be even more urgent. [1] https://svn.boost.org/trac/boost/ticket/12291 [2] https://svn.boost.org/trac/boost/ticket/12292 [3] https://github.com/boostorg/type_erasure/pull/9 [4] https://github.com/boostorg/type_erasure/pull/10 [5] https://github.com/boostorg/type_erasure/pull/11 -- BENOCS GmbH Dipl.-Inform. Deniz Bahadir Winterfeldtstr. 21 10781 Berlin Germany Phone: +49 - 30 / 577 0004-22 Email: deniz.bahadir(a)benocs.com www.benocs.com Board of Management: Michael Wolz, Dr.-Ing. Oliver Holschke, Dr.-Ing. Ingmar Poese Commercial Register: Amtsgericht Bonn HRB 19378

2 1

[Hana/Fit] about constexpr/noexcept on equivalent functions to std::overload
by Vicente J. Botet Escriba 08 Jul '16

08 Jul '16

Hi, On the C++ standard meating in Oulu, we decided to make the std::overload function constexpr and conditionaly noexcept and ensure that the overloaded functions shall be constexpr if the stored finctions are. I don't find in the reference documentation of Hana and Fit any reference of whether the overloaded functions preserve constexpr or not. There is a reedit post [1] and CWG issue 1581 [2] that are related. Could the authors clarify? What other think? Best, Vicente [1] https://www.reddit.com/r/cpp/comments/35g7f6/c17_progress_update/cr4mvid [2] http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#1581

3 6

[config] msvc-14 config changes heads up
by John Maddock 08 Jul '16

08 Jul '16

I've just pushed some changes to develop so that MSVC-14.0 update 3 no longer defines: BOOST_NO_CXX14_VARIABLE_TEMPLATES BOOST_NO_SFINAE_EXPR BOOST_NO_TWO_PHASE_NAME_LOOKUP As far as I can tell, these cause no new regressions in develop, please let me know if I've missed something. I haven't stopped defining BOOST_NO_CXX11_CONSTEXPR as it causes new failures: * Multiprecision, one new failure when using constexpr features, looks harmless. * Metaparse, causes the compiler to run out of resources on a couple of tests - these test non-default values of BOOST_METAPARSE_LIMIT_STRING_SIZE and are probably harmless. * Type_erasure, causes one new runtime failure. * Chrono, nothing much compiles - this one is the showstopper and needs investigating - any takers? Best, John.

7 13

[qvm] help with tests
by Emil Dotchevski 06 Jul '16

06 Jul '16

It appears that the QVM tests are broken somehow but it isn't clear to me what might be wrong. It shows "pass" next to __boost_check_library__, but there are no results for the actual tests. It used to work fine earlier -- this issue might be related somehow to a previous problem, where I had a build directory without realizing that the test framework recognized that name and did things I did not intend; so I renamed the build directory to bld. Can someone help me fix this? Thanks, Emil

3 7

Re: [boost] Boost numeric conversion - unary function deprecated or removed for C++17
by Brandon Kohn 06 Jul '16

06 Jul '16

Sent from Mail for Windows 10 From: Paul A. Bristow Sent: Monday, July 4, 2016 12:48 PM To: boost(a)lists.boost.org Subject: [boost] Boost numeric conversion - unary function deprecated or removed for C++17 >Can anyone help please. I’ve pushed fixes for this. _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost

3 4

Boost numeric conversion - unary function deprecated or removed for C++17
by Paul A. Bristow 06 Jul '16

06 Jul '16

I need to use C++17 (or MSVC std:c++latest) for other reasons, but I am blocked on MSVC by failure to compile converter.hpp It works OK on GCC 6.1.1 but not on VS2015 update 3 http://stackoverflow.com/questions/33114656/replacement-for-binary-function http://stackoverflow.com/questions/33114656/replacement-for-binary-function I suspect that GCC has not yet removed the deprecated unary_function but that MSVC correctly has removed it? Updating this looks above my pay grade. Can anyone help please. Paul --- Paul A. Bristow Prizet Farmhouse Kendal UK LA8 8AB +44 (0) 1539 561830

3 2

[1.61.0][container] Error compiling alloc_lib.c with -std=c++11
by Richard Hadsell 05 Jul '16

05 Jul '16

I am trying to build Boost 1.61.0 with Clang and C++11 features. Other parts of the library warn about using C++11 features, if I do not build with the option -std=c++11. However, this C source file gives an error, and I assume it does not build at all: clang-linux.compile.c.without-pth bin.v2/libs/container/build/clang-linux-3.5.0/release/instruction-set-core2/threading-multi/alloc_lib.o error: invalid argument '-std=c++11' not allowed with 'C/ObjC' "[snip]clang++" -c -x c -O3 -Wno-inline -Wall -std=c++11 -fPIC -gcc-toolchain [snip]gcc/4.8.3 -Wno-[snip] -march=core2 -pthread -fPIC -m64 -DBOOST_ALL_NO_LIB=1 -DBOOST_CONTAINER_DYN_LINK=1 -DNDEBUG -I"." -c -o "bin.v2/libs/container/build/clang-linux-3.5.0/release/instruction-set-core2/threading-multi/alloc_lib.o" "libs/container/src/alloc_lib.c" ...failed clang-linux.compile.c.without-pth bin.v2/libs/container/build/clang-linux-3.5.0/release/instruction-set-core2/threading-multi/alloc_lib.o... These are the options from my user-config: using clang : 3.5.0 : [snip]/clang++ : <compileflags>"-std=c++11 -fPIC -gcc-toolchain [snip]/gcc/4.8.3 -Wno-[snip]" <linkflags>"-fPIC -gcc-toolchain [snip]/gcc/4.8.3" ; I don't see a way to provide C++-only flags or C-only flags. Actually, I thought that all Boost source files would be C++. -- Dick Hadsell 203-992-6320 Fax: 203-992-6001 Reply-to: hadsell(a)blueskystudios.com Blue Sky Studioshttp://www.blueskystudios.com 1 American Lane, Greenwich, CT 06831-2560

2 2

[meta] Hidden libraries.
by Daniel James 04 Jul '16

04 Jul '16

I just noticed that 'detail' and 'winapi' have started turning up in the library lists because they've added metadata files. We've always hidden these libraries in the past, so I'm thinking of adding an extra field to mark them as private/hidden libraries. Probably just something like: { "key": "detail", "name": "Detail", "private": true /* the rest.... */ } Any opinions?

4 4

[release] please add fiber to master
by Oliver Kowalke 03 Jul '16

03 Jul '16

Hello admins, I'd like to ask you to add boost.fiber to the master branch so that it will become part of the next boost release (1.62). thank you in advance, Oliver

3 7

What kind of algorithms/data structures can enter in Boost
by Зайцев Александр 03 Jul '16

03 Jul '16

Hello. I am interested in developing data structures and some algorithms in Boost library. But one of the requierement for library is: "The library should be generally useful". What does it mean? I think, that i can add to the library some more data structures: suffix tree/array/automata, palindromic tree, modifications of stack/queue for getting min/max with O(1), Aho–Corasick(maybe it's algo already exist in Boost Library), maybe something else (kd-tree, for example). And algortihms: Manacker's algo for calculating palindromes number, Longest increasing subsequence, palindromic check. There are many algorithms, which i can implement to the Boost library. Also Boost.Math versus GNU MP library is very simple. In GNU MP there are many useful features. And i don't know? we need to provide these features to the Boost.Math or not. Ok, Who can explain me, what algorithms of those that i mentioned, is generally useful? What is useful for Boost, and what is useless? Thanks. -- Best regards, Zaitsev Alexander

3 4

defect macro for thread_local?
by Oliver Kowalke 02 Jul '16

02 Jul '16

Hi, does boost provide a defect macro for thread_local (like BOOST_NO_CXX11_THREAD_LOCAL)? I couldn't find something similar int the boost macro reference. The macro would be helpful together with the feature-check to exclude compilers, that do not support the keyword thread_local (as gcc-4.7. and apple's compiler), from unit-tests. Oliver

4 7

[1.61.0] building with Clang and c++11
by Richard Hadsell 02 Jul '16

02 Jul '16

I have downloaded 1.61.0 and want to build it with Clang. This is in my user-config: using clang : 3.5.0 : /netDISKS/master/netmt/LINUX_C65/app/clang/3.5.0/bin/clang++ : <compileflags>"-fPIC -gcc-toolchain /netDISKS/master/netmt/LINUX_C65/app/gcc/4.8.3 -Wno-overloaded-virtual -Wno-unused-function -Wno-unused-variable -Wno-c99-extensions -Wno-variadic-macros" <linkflags>"-fPIC -gcc-toolchain /netDISKS/master/netmt/LINUX_C65/app/gcc/4.8.3" ; When I build, I see warnings like these: ./boost/mpl/print.hpp:50:19: warning: in-class initialization of non-static data member is a C++11 extension [-Wc++11-extensions] const int m_x = 1 / (sizeof(T) - sizeof(T)); ^ ./boost/timer/timer.hpp:44:43: warning: 'long long' is a C++11 extension [-Wc++11-long-long] void clear() { wall = user = system = 0LL; } ^ ./boost/regex/v4/instances.hpp:124:34: warning: unknown warning group '-Wkeyword-macro', ignored [-Wunknown-pragmas] #pragma clang diagnostic ignored "-Wkeyword-macro" ^ When I add '-std=c++11' to the <compileflags> and <linkflags>, I get errors and warnings like these: clang-linux.compile.c.without-pth bin.v2/libs/container/build/clang-linux-3.5.0/release/instruction-set-core2/link-static/threading-multi/alloc_lib.o error: invalid argument '-std=c++11' not allowed with 'C/ObjC' "/netDISKS/master/netmt/LINUX_C65/app/clang/3.5.0/bin/clang++" -c -x c -O3 -Wno-inline -Wall -std=c++11 -fPIC -gcc-toolchain /netDISKS/master/netmt/LINUX_C65/app/gcc/4.8.3 -Wno-overloaded-virtual -Wno-unused-function -Wno-unused-variable -Wno-c99-extensions -Wno-variadic-macros -march=core2 -pthread -m64 -DBOOST_ALL_NO_LIB=1 -DBOOST_CONTAINER_STATIC_LINK=1 -DNDEBUG -I"." -c -o "bin.v2/libs/container/build/clang-linux-3.5.0/release/instruction-set-core2/link-static/threading-multi/alloc_lib.o" "libs/container/src/alloc_lib.c" libs/locale/src/shared/localization_backend.cpp:54:22: warning: 'auto_ptr' is deprecated [-Wdeprecated-declarations] std::auto_ptr<localization_backend> res(new actual_backend(backends,default_backends_)); ^ ./boost/regex/v4/instances.hpp:124:34: warning: unknown warning group '-Wkeyword-macro', ignored [-Wunknown-pragmas] #pragma clang diagnostic ignored "-Wkeyword-macro" ^ What options do I need to add or remove to build and use boost with no errors and as few warnings as possible? -- Dick Hadsell 203-992-6320 Fax: 203-992-6001 Reply-to: hadsell(a)blueskystudios.com Blue Sky Studios http://www.blueskystudios.com 1 American Lane, Greenwich, CT 06831-2560

5 6

New library? CallableTraits
by Barrett Adair 01 Jul '16

01 Jul '16

I posted about this a month ago, but I did not receive much response. Since then, I added an extended example use case, and I added a documentation section [1] that compares CallableTraits and Boost.FunctionTypes. I received some positive feedback this week in Aspen, and r/cpp also seemed to respond well [2], so I thought I'd give this another shot. Here are my questions for you: 1. Is there any interest in reviewing a future version of this for inclusion in Boost? 2. If so, does this belong in its own library, or should it be incorporated into Boost.TypeTraits or something similar? 3. What you like to see added, removed, renamed, or redesigned? I'd say CallableTraits is about 85% finished. Here's what's left: * Add INVOKE semantics to a couple of things for consistency (arity, etc) * Remove unused/undocumented code * Account for transaction_safe and C++17 noexcept * Finish/test the calling convention features * Finish/update the reference documentation * Write even more tests Cheers, Barrett [1] http://badair.github.io/callable_traits/doc/html/index.html#callable_traits… [2] https://www.reddit.com/r/cpp/comments/4ffmfs/callabletraits_never_write_ano… GitHub: https://github.com/badair/callable_traits Documentation from the top: http://badair.github.io/callable_traits/doc/html/index.html (reference section under construction)

5 11

[build] Running 1 per N tests
by Adam Wulkiewicz 30 Jun '16

30 Jun '16

Hi, At Boost.Geometry we're using CircleCI for testing. They allow to run the tests concurently on N virtual machines. I'd like to alter my script to automatically redistribute the tests evenly across all of the machines, i.e. to run 1/N of the tests on each machine. The problem is that at Boost.Geometry we have a lot of nested project directories, i.e. b2 executed for some upper directory runs the tests in the test-suite in this directory and then follows nested projects defined by build-project directives, so runs the tests recursively. So e.g. if b2 was executed on some virtual machine for the most-top-level directory all of the tests would be built anyway. Do you have an idea how this could be solved without altering the tests structure? Is it currently somehow possible (though AFAIK it isn't) or would be possible to implement options allowing to e.g.: - run b2 only for a certain directory/Jamfile, e.g. --non-recursive - ignore arbitrary Jamfile directive, e.g. --ignore-build-project - run only 1 per N tests, an option used together with -jX but running tests only for one thread, e.g. b2 -i2 -j4 running only 1 per 4 commands starting from 2nd command ? The last option would be the most convenient for me. The tests would be divided as evenly as possible. It wouldn't require to use some workarounds i.e. traversing test directories recursively and running b2 manually for them which could result in low-quality redistribution, e.g. if some directory contained many tests and other small number of tests. Regards, Adam

2 2

boost regression run.py fails with, fatal: Not a git repository
by Blower, Melanie 29 Jun '16

29 Jun '16

I'm trying to run.py on develop to report results with the Intel compiler. The script I use first downloads run.py. The git is failing partway through with this message Cloning into 'tools/quickbook'... Submodule path 'tools/quickbook': checked out 'c7cb99ac029593024f3f31a1ab2503820f1300d5' # Cleaning up "/localext3/mblower/sandbox/_try_dev/boost_root/bin" directory ... # Cleaning up "/localext3/mblower/sandbox/_try_dev/boost_root/bin.v2" directory ... # Cleaning up "/localext3/mblower/sandbox/_try_dev/results" directory ... # Getting sources (2016-06-29T12:24:07Z)... # Executing GIT command: /localext3/mblower/sandbox/_try_dev/boost_root> git submodule foreach "cd $toplevel && git submodule deinit $path" Entering 'libs/accumulators' fatal: Not a git repository (or any parent up to mount point /localext3) Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set). Stopping at 'libs/accumulators'; script returned non-zero status. # git_source_checkout failed with message "GIT command "git submodule foreach "cd $toplevel && git submodule deinit $path"" failed with code 256" I'm using a new server, the "master" results completed successfully last night. There's plenty of disk space. Any ideas?

2 1

[boost-git] fiber not contained?
by Oliver Kowalke 29 Jun '16

29 Jun '16

Hi, I was asked several times why boost.fiber is not contained if boost's git-repo is cloned with git clone --recursive http://github.com/boostorg/boost.git. I'm wondering because boost.fiber is already included in the regression tests (master/develop). Oliver

4 8

Attention library authors.. Library requirements testing is now active.
by Rene Rivera 29 Jun '16

29 Jun '16

As part of continued efforts to move testing to CI, to facilitate release management, and to provide more information to authors I've now implemented some testing changes: 1. Most libraries are now tested automatically if they have a usable test directory. There are still libraries that do not follow the requirements of having all their tests in just the single test directory. You can see which ones those are here < https://github.com/boostorg/boost/blob/develop/status/Jamfile.v2#L101>. Library authors should IMMEDIATELY make changes to their test/Jamfile's to follow the library requirements for testing. Before the next release I plan to blindly remove that custom list of extra test targets. 2. Most structure library requirements are now checked both in the regular full testing and in the CI testing. I've implemented a script to check for most of the library directory structure and integration requirements. The script runs as an additional CI job, currently in Travis. Here's one of those jobs < https://travis-ci.org/boostorg/boost/jobs/137506433>. At the moment it reports 17 libraries as having errors. There are also some warnings, i.e. not requirement violations but just some stuff that may be wrong. The script also runs as part of the general full testing and any problems are reported in each library's results as a single entry at the top of the tables. Here's how one of the test failures looks like < http://tinyurl.com/zbe9gal> [1] [2]. It would be great if library authors address those errors in some form ASAP. I know that for some of those reported libraries there will need to be some discussions as to how to best address the errors. Feel free to start additional threads for those as needed. [1] < http://www.boost.org/development/tests/develop/developer/output/teeks99-09f… > [2] Note there are currently some false failures in this aspect from a build system "bug". The bug is already fixed but tests will take some time to cycle to reflect the bug fix. -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net -- rrivera/acm.org (msn) - grafikrobot/aim,yahoo,skype,efnet,gmail

11 23

Query: ADL vs MSVC2013 support
by Soul Studios 28 Jun '16

28 Jun '16

I have transplanted the advance/next/prev/distance member functions into ADL non-member functions in a current unreleased version of colony (plflib.org) My question is whether MSVC2013 support for these functions is more important to the boost community than them being ADL. There's a bug in MSVC2013 (fixed in MSVC2015, never backported to MSVC2013) that causes a compiler crash under certain template configurations - unfortunately the way that the ADL has to be implemented (I have tried several methods) causes this bug. The workaround would be to disable these functions in MSVC2013 only, as everything works fine in MSVC2010, MSVC2015, Clang 3.6-3.8 (have not tested earlier) and GCC 4.6-5.1 (have not tested earlier).

1 1

message: Build #2 is still failing.
by Robert Ramey 26 Jun '16

26 Jun '16

I'm getting these messages on aregular basis. They point to the url https://travis-ci.org/boostorg/serialization/builds/140270355 I can see the utility of this. It seems that this is due to some requirement that I'm not fulfillng in the serialization library test directory.... or something. What, if anything, should I do about this. Robert Ramey

2 1

enabling constexpr with Visual studio 2015 Update 3 (RC)
by Paul A. Bristow 24 Jun '16

24 Jun '16

I am trying to use the enhanced constexpr features and have (perhaps unwisely) downloaded the latest Visual Studio Update 3 (RC) to get as great a chance of achieving this as possible. https://blogs.msdn.microsoft.com/vcblog/2015/12/02/constexpr-in-vs2015-upda… (and later posts) I am unsure what I need to do to ensure that the compiler is enabled for use the latest features. I have added /std:c++14 to the options of the property for the project. (aside I also tried /std:C++latest but that works for some tasks but failed to compile with odd-looking errors in converter.hpp Error C2518 keyword 'typename' illegal in base class list; ignored \modular-boost\boost\numeric\conversion\detail\converter.hpp 453 // Trivial Converter : used when (cv-unqualified) T == (cv-unqualified) S // template<class Traits> struct trivial_converter_impl : public std::unary_function< BOOST_DEDUCED_TYPENAME Traits::argument_type ,BOOST_DEDUCED_TYPENAME Traits::result_type > ,public dummy_range_checker<Traits> {...} So I stopped trying that /std:c++latest option. What else should it do?) Running the modular-boost/libs/config/config_info.cpp program BOOST_NO_CXX14_CONSTEXPR [no value] BOOST_CONSTEXPR [no value] BOOST_CONSTEXPR_OR_CONST =const BOOST_STATIC_CONSTEXPR =static const These don't seem to be what I think that I would expect (constexpr and static constexpr). I want especially to use BOOST_STATIC_CONSTEXPR to get static constexpr. Do I need to also add #define BOOST_CXX14_CONSTEXPR in my program or elsewhere? (Doing this doesn't change BOOST_CONSTEXPR_OR_CONST from const to constexpr) Thanks for any suggestions. Paul --- Paul A. Bristow Prizet Farmhouse Kendal UK LA8 8AB +44 (0) 1539 561830

8 16

[typeof] Pull requests
by Adam Wulkiewicz 23 Jun '16

23 Jun '16

Hi, There are trivial pull requests in TypeOf waiting for merging (https://github.com/boostorg/typeof/pulls) One of them is more than 2 yo. Would it be possible to merge them? At least #3 or #4 should be merged. Regards, Adam

1 0

Additional Test Configurations
by Tom Kent 22 Jun '16

22 Jun '16

About a month ago I got three new machines dedicated to testing boost online (thanks to Boost Community/Steering Committee/Conservancy!). These three machines are currently running tests along with a couple other machines that I have. Now that things are up and running, I'm looking for some community input as to how best utilize them. Here's the current setup: teeks99-01 - Ubuntu 14.04 + Docker - gcc-4.4 (master + develop) Docker precise + ubuntu-toolchain-r/test - gcc-4.5 (master + develop) Docker precise + ubuntu-toolchain-r/test - gcc-4.6 (master + develop) Docker precise + ubuntu-toolchain-r/test - gcc-4.7 (master + develop) Docker precise + ubuntu-toolchain-r/test - gcc-4.8 (master + develop) Docker trusty + ubuntu-toolchain-r/test - gcc-4.9 (master + develop) Docker trusty + ubuntu-toolchain-r/test - gcc-5 (master + develop) Docker trusty + ubuntu-toolchain-r/test - clang-3.0 (master + develop) Docker trusty + h-rayflood/llvm - clang-3.1 (master + develop) Docker trusty + h-rayflood/llvm - clang-3.2 (master + develop) Docker trusty + h-rayflood/llvm - clang-3.3 (master + develop) Docker trusty + ubuntu-toolchain-r/test - clang-3.4 (master + develop) Docker trusty + ubuntu-toolchain-r/test - clang-3.5 (master + develop) Docker trusty + ubuntu-toolchain-r/test - clang-3.6 (master + develop) Docker trusty - clang-3.7 (master + develop) Docker trusty + llvm.org/apt teeks99-02 - Ubuntu 16.04 + Docker - gcc-4.4 (master + develop) Docker precise + ubuntu-toolchain-r/test - gcc-4.5 (master + develop) Docker precise + ubuntu-toolchain-r/test - gcc-4.6 (master + develop) Docker precise + ubuntu-toolchain-r/test - gcc-4.7 (master + develop) Docker precise + ubuntu-toolchain-r/test - gcc-4.8 (master + develop) Docker trusty + ubuntu-toolchain-r/test - gcc-4.9 (master + develop) Docker trusty + ubuntu-toolchain-r/test - gcc-5 (master + develop) Docker trusty + ubuntu-toolchain-r/test - clang-3.0 (master + develop) Docker trusty + h-rayflood/llvm - clang-3.1 (master + develop) Docker trusty + h-rayflood/llvm - clang-3.2 (master + develop) Docker trusty + h-rayflood/llvm - clang-3.3 (master + develop) Docker trusty + ubuntu-toolchain-r/test - clang-3.4 (master + develop) Docker trusty + ubuntu-toolchain-r/test - clang-3.5 (master + develop) Docker trusty + ubuntu-toolchain-r/test - clang-3.6 (master + develop) Docker trusty - clang-3.7 (master + develop) Docker trusty + llvm.org/apt teeks99-03 - Ubuntu 16.04 + Docker - gcc-5 (develop) Docker trusty + ubuntu-toolchain-r/test - clang-3.7 (develop) Docker trusty + llvm.org/apt teeks99-05 - Ubuntu 14.04 (Azure VM) - gcc-4.8 (master) - clang-3.4 (master) teeks99-08 - Windows 2012 (KVM VM) - msvc-8.0 (master + develop) SP1 - msvc-9.0 (master + develop) SP1 - msvc-10.0 (master + develop) SP1 - msvc-11.0 (master + develop) Update 4 - msvc-12.0 (master + develop) Update 5 - msvc-14.0 (master + develop) Update 2 teeks99-09 - Windows 2012 (KVM VM) - msvc-8.0 (master + develop) SP1 - msvc-9.0 (master + develop) SP1 - msvc-10.0 (master + develop) SP1 - msvc-11.0 (master + develop) Update 4 - msvc-12.0 (master + develop) Update 5 - msvc-14.0 (master + develop) Update 2 I'm currently working on getting gcc-6 and clang 3.8, sorry they aren't in the list yet. I'm planning to retire the teeks99-01 shortly and converting the ancient teeks99-05 to something newer, still doing boost testing. All these configurations and the scripts that keep them cycling are on github at: https://github.com/teeks99/boost-build For each platform there are a couple configurations that I try to run frequently to give 'rapid' results as developers are committing code. The configurations for windows are set so that every few runs it will run the msvc-12.0 (develop) test, so that is never more than ~10hrs old. Similarly on linux, the gcc-5 and clang-3.7 (develp) tests get run every few hours. Just to give a feeling of the timing, Linux runs take .75-3 hrs and Windows runs take 1.5-4hrs, depending on compiler, os, hardware, etc. All these configurations have minimal compiler options set. MSVC + GCC builds have no options set, clang has `<cxxflags>-Wno-c99-extensions`. >From a lot of the discussing I've seen on the lists, it seems that there's a lot of work going into C++ 11/14/1z development. I was thinking it would be good to add some of those switches. Which ones? How many? Baseline Standard -std=c++98 (I believe this is the default for all the g++/clang++ instances above) -std=c++11/0x -std=c++14/1y -std=c++1z GNU Standard -std=gnu++98 -std=gnu++11/0x -std=gnu++14/1y -std=gnu++1z Clang Library -stdlib=libc++ -stdlib=libstdc++ Optimization -O2? Warnings -Wall -Wextra Others? I'm guessing that most of these will be of interest to at least a small subset of developers. There probably isn't a need to apply all possible combinations to all possible compilers however. (Not to mention that it would make the results matrix even more overwhelming.) Which combinations are important for you to see in the matrix? What do you think should be the 'rapid' configurations? I'm also thinking about additional compilers (in addition to gcc-6/clang-3.9 mentioned above), though these will take a bit of work on my part, so will only get implemented as I have time available. - gcc HEAD from GIT - clang HEAD from GIT - cygwin/gcc - mingw - clang on windows - Other? Thanks in advance for your input! Tom

6 12

[boost.process] 0.6 Alpha
by Klemens Morgenstern 21 Jun '16

21 Jun '16

Hi all, the boost.process 0.6 library is now in alpha, that is: it has some (compiling) examples, a documentation and tests that pass on windows as well as on linux. It basically allows you to manage a process like this: pstream pipe; child c("some_prog", "--some-arg", env["PATH"]+="C:/stuff", std_in < "data.csv", std_out > pipe, std_err > null, start_dir="./bin"); std::string data; pipe >> data; c.wait(); cout << c.exit_code() << endl; You can find the documentation here: http://klemens-morgenstern.github.io/process/ Get the source code from here: https://github.com/klemens-morgenstern/boost-process If you want to use it on windows, you currently would need to clone my boost.winapi fork also: https://github.com/klemens-morgenstern/winapi As for the scope of the library, it is meant to implement a small, portable layer to allow platform-independent process management. Thereby it's functionality is (unless I missed something) basically what is possible on posix as well as on windows. There are some platform extension, but I would not recommend to use them. It is also possible (though not yet documented) to write extensions, and if they work on both platforms I will gladly add them. It is however not the goal of the library, to be the be-all and end-all of process management; in past disscussions, different ideas where brought up, like implementing a DSEL for that or only allowing asynchronous communication. This library will never be that, since it would be much more fitting to build this on-top of it. E.g. a DSEL could be written (e.g. boost.shell) using boost.process underneath, so the library could concentrate only on the DSEL. It doesn't depend on boost.iostreams anymore, though it still uses boost.asio, boost.fusion and boost.filesystem. As for the open issues: some error handling is still lacking (but that'd be something like being unable to duplicate a handle), which would be required for proper extension, which is also why it's not documented. Also there's still an open discussion about the naming of the class and functions (child, system, spawn), so that may change also. But I consider this simple enough for a easy refactoring. If anyone has naming ideas, please tell me. One Idea was 'subprocess' but 'process::subprocess' just looks too strange to me. I hope you try it out, and give me some feedbacks. Or write angry error reports, both helps. Thanks! Klemens

8 32

Checking interest in stacktrace library
by Antony Polukhin 21 Jun '16

21 Jun '16

Hi, I've got some prototype for getting stack traces: https://github.com/apolukhin/stacktrace It's design is based on the idea that class for stacktrace must be fully noexcept, without dynamic allocations in constructors and as simple as possible. Is there interest in it? What functionality would you like to have in it? -- Best regards, Antony Polukhin

9 10

Re: [boost] proposed new library "histogram"
by Bjorn Reese 20 Jun '16

20 Jun '16

On 05/05/2016 12:21 AM, Hans Dembinski wrote: > https://github.com/HDembinski/histogram I suggest that you use non-intrusive serialization and place that in separate headers, so there is no dependency on Boost.Serialization unless you need it.

2 4

Checking interest in clang-{format, tidy} configurations
by jerry.c.t＠web.de 19 Jun '16

19 Jun '16

Hi, is there an interest for common boost clang-format and clang-tidy (only the module readability-identifier-naming) configurations to inforce consistent layout and naming style? For clang-format there are predefined styles like llvm, google etc. I think about adding a new predefined style 'boost' to clang-format. But first i would start with a separate _clang-format file. For clang-tidy there are no predefined styles thus i would simply create a _clang-tidy file. Best regards, Jerry

2 1

Feature request: variant::view
by TONGARI J 19 Jun '16

19 Jun '16

Hi, Sometimes we need to view a value as a variant and we don't want to copy the value into a variant. It'd be great if there's a variant::view that works like a variant but holds a reference to the value instead. The constructor should allow any reference to the types as in the variant, and a constructor that takes a reference to the variant, e.g. template<class T1, class T2...> class variant<T1, T2...>::view { view(T1&); view(T2&); ... view(variant&); }; And we can use apply_visitor/get on a view as on a variant. Thoughts? Thanks.

2 2

Boost's List of improvements
by Зайцев Александр 19 Jun '16

19 Jun '16

Hello. I will prepared Boost's list of improvements. I can realize it. Maybe, some algorithms I only can't find in Boost. And i think, that if i will implement algorithms from this list, it's will be great. Improvement list for Boost.Algorithm Boost.Algorithm(String) 1) Manacker's Algorithm: finding all palindromes in string O(N). 2) Different algortihms based on suffix arrays and suffix trees: Boost.Algorithm(Numbers) 1) Checking for number's simplicity by BPSW test. O(logN). 2) Effective factorization algorithms: Po, Po-1, Bents algo, Po-Monte-Carlo, Ferms algo. 3) Longest increasing subsequence Boost. Container 1) Modifications of queue and stack for searching min/max element with O(1). Maybe, I forgot something. -- Best regards, Zaitsev Alexander

1 0

Book
by Robert Ramey 18 Jun '16

18 Jun '16

I've attached an epub version of my "book". You should be able to just click on it and have the apple book reader popup and then be able to read it. The apple book reader has some interesting features. a) the book looks pretty good considering I didn't have to put to much effort into the formatting etc. b) For our purposes the best part is that you can easily annotate the book! There are three icons in the upper left corner. One to display the table of contents and other one for "notes" You can highlight text and add a note to it then save the book !. This is perfect as far as I'm concerned. Please don't spend time "copy editing" it. The whole thing needs to be gone over with a fine tooth comb with the idea of making the text more readable and clear, that the examples are in sync with the text, probably more narrative etc. etc. I'm really mostly concerned that the concepts are readable and explained to the target reader. Since I discovered the notion of semiring I understand the my C++ type algebra fulfills all the requirements of a semiring. And there is a large list of theorms which apply to semirings. I don't intend to add too much to the section, at least for now. It is very interesting but but right not it doesn't yet have a practical application. I'm hoping that will change but for now I it's as far as I want to go with this. This section will also need some work as far at the math is concerned. There are some issues with the notion of an inverse of a type etc which are still not really finished. But for now I think I've got the concepts outlined. It generates a book 60 pages long.

4 4

Re: [boost] [Boost-users] Checking interest in stacktrace library
by Antony Polukhin 18 Jun '16

18 Jun '16

2016-06-18 17:49 GMT+03:00 Edward Diener <eldiener(a)tropicsoft.com>: > On 6/18/2016 6:34 AM, Antony Polukhin wrote: > >> Is there interest in it? >> What functionality would you like to have in it? >> > > Documentation is always helpful. > Yeep, that's currently missing :( If in short: namespace boost { namespace stacktrace { class stacktrace { public: BOOST_STATIC_CONSTEXPR std::size_t max_symbol_width = 256; typedef boost::array<char, max_symbol_width> frame_t; stacktrace() BOOST_NOEXCEPT; stacktrace(const stacktrace& bt) BOOST_NOEXCEPT; stacktrace& operator=(const stacktrace& bt) BOOST_NOEXCEPT; ~stacktrace() BOOST_NOEXCEPT; std::size_t size() const BOOST_NOEXCEPT; frame_t operator[](std::size_t frame) const BOOST_NOEXCEPT; }; template <class CharT, class TraitsT> std::basic_ostream<CharT, TraitsT>& operator<<(std::basic_ostream<CharT, TraitsT>& os, const stacktrace& bt); }} So you can construct stacktraces, copy them and output them to streams: std::cerr << stacktrace(); -- Best regards, Antony Polukhin

1 0

Library addition request
by Gerrit Daniels 18 Jun '16

18 Jun '16

Hello, I've written a library that implements automatic serialization of user defined types. You can find it here: https://github.com/gerritdaniels/ctrl. I was wondering if this is something that could be added to the boost library. Kind regards, Gerrit Daniels.

6 10

Stand-alone Boost.Python
by Stefan Seefeld 18 Jun '16

18 Jun '16

Hello, I have started working on a new SCons-based build infrastructure for Boost.Python that allows the Boost.Python code to be compiled stand-alone against a pre-installed Boost. I have checked in a first version to the develop branch, and have enabled Travis-CI to use that. While this works reasonably well, and provides a much simpler workflow for developers wanting to contribute to Boost.Python, it isn't (yet) entirely feature-complete. Notably, running this on Windows (using MSVC) produces errors. I'd appreciate any help with this, especially from Windows users who are more familiar with MSVC than I am (that shouldn't be hard, given I have next to no experience with using MSVC :-) ). Building Boost.Python is now very simple: * clone the repo via `git clone https://github.com/boostorg/python.git` and switch to the 'develop' branch * configure a build via `scons config --python=... --boost-prefix=...` * build and test via `scons test` Hopefully this will make it much simpler to contribute and test patches, so we can work down the list of accumulated PRs and issues. (For avoidance of doubt: for the immediate future I have no intentions to replacing the official bjam-based build system. But once the new one has proven to be stable enough, I expect to actually build stand-alone releases for Boost.Python.) Thanks, Stefan -- ...ich hab' noch einen Koffer in Berlin...

1 0

Using Boost with VS 14.0 update 3 RC and Clang 3.8.0 (from CodeBlocks IDE) compile fails in MS type_traits is_assignable
by Paul A. Bristow 15 Jun '16

15 Jun '16

I am trying to check a program that compiles on VS with 14.0 update 3 RC and on Codeblocks IDE GCC 5.3 compile OK, but CodeBlocks Clang 3.8.0 fails: C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\include\type_traits:524:45: error: '_To' does not refer to a value : integral_constant<bool, __is_assignable(_To, _From)> I:\modular-boost\boost\mpl\aux_\preprocessed\plain\or.hpp|58|error: pasting formed 'BOOST_PP_TUPLE_ELEM_O_3(', an invalid preprocessing token [-Winvalid-token-paste] and terminally many more. clang++.exe -Wall -std=c++14 -m64 -fexceptions -O4 -m64 -std=c++14 -fms-extensions -Wall -m64 -fms-compatibility-version=19.00 -II:\modular-boost -c J:\Cpp\hellos\fixed_point_constexpr\fixed_point_constexpr.cpp -o obj\Release\fixed_point_constexpr.o I see some discussion of similar problem on https://groups.google.com/forum/#!topic/boost-list/MvqaK4SDy_c and a possible apparent fix on https://github.com/boostorg/type_traits/pull/24 Any suggestions for working around this problem? Paul PS I may try to use a *nix platform for this. --- Paul A. Bristow Prizet Farmhouse Kendal UK LA8 8AB +44 (0) 1539 561830

2 1

[density] new library
by Giuseppe Campana 14 Jun '16

14 Jun '16

Hi to all, I'm working to density, a C++11 header-only library for heterogeneous containers and lifo memory management. It is not complete, but it is very close (and usable already). Just to avoid confusion, the test project of density contains a sub-module called testity, that in a near future will become a separate library. I'm wondering if it may become a valid proposal for a new library. In any case, any kind of feedback is welcome. Source code at https://github.com/giucamp/density Documentation at http://peggysansonetti.it/tech/density/html/index.html Regards, Giuseppe Campana.

6 9

[property_tree] Quoting documentation
by alainm 13 Jun '16

13 Jun '16

Hi, I am using property_tree for a project, and I'd like to provide a description of the format. That text is exactly what I need: http://www.boost.org/doc/libs/1_61_0/doc/html/property_tree/parsers.html#pr… I am going to provide a link to the doc, but would need to insert the text into the documentation pdf too (some people actually still read paper). Is it possible and what kind of copyright text should I use ? Thanks Alain

2 1

Start to contribute to Boost.
by Зайцев Александр 11 Jun '16

11 Jun '16

Hello. I very want to start contribute to Boost library. I want to help this project. And... maybe for start i can try to fix some bugs. Can you give me some pieces of advice, what i can do at start? Thanks. -- С уважением, Зайцев Александр.

3 2

Pimpl Again?
by Vladimir Batov 10 Jun '16

10 Jun '16

Don't laugh but it is only fairly recently at work that I managed to move all our supported platforms to C++11. So, then, I started moving our code to C++11 (what a delight!) and stumbled upon my old pimpl which is used quite a bit around my workplace for all its good properties... :-) Now C++11-ed piml turned out to be very small and very basic. So basic it felt it did not have the right to exist. Still, it encapsulates and enforces the "proper" pimpl properties and behavior, reduces implementation minutia and offers a recognizable deployment pattern (helps other people reading the code). Over the years IMO the technique has been proven as legitimate and useful, a basic but important building block... rather than a curiosity item. Unfortunately, despite many articles and a few Sutter's GotWs about it there is nothing ready-to-go like std::unique_ptr. I feel that pimpl and its deployment pattern need to be codified, described, "standardized" and in our toolboxes to stop/avoid everyone re-inventing the pimpl and making the same mistakes. IMO Boost is best positioned for that. Do you think we might review what I've got and/or maybe collectively come up with something better... It's no MPL or Hana but as std::unique_ptr it's one of the first "little things" I personally reach out for in my everyday work. IMO having pimpl in Boost would save quite a few hours of frustration for many. Thoughts? No pressure. I am easy either way. :-) https://github.com/yet-another-user/pimpl Docs are freshened up but still somewhat out of date. Apologies.

15 84

[config] Changes needed for VC++ 2015 Update 3?
by Beman Dawes 09 Jun '16

09 Jun '16

The VS 2015 Update 3 release candidate has been announced. See https://blogs.msdn.microsoft.com/vcblog/2016/06/07/compiler-improvements-in… (The following is partially for Boost developers who care about msvc, and partially to remind myself of what may need to be done to support update 3. It will be several weeks before I can work on this, so if any of the other config maintainers want to step in, please do so.) Update 3 supports standards versioning switches similarly to gcc, clang, and other compilers. We probably want to update Boost.Config accordingly. See https://blogs.msdn.microsoft.com/vcblog/2016/06/07/standards-version-switch… Update 3 fixes lots of constexpr bugs, so we need to review whether or not BOOST_NO_CXX11_CONSTEXPR is still required. Note that in develop there is an undocumented config macro BOOST_MSVC_CXX11_CONSTEXPR that turns off BOOST_NO_CXX11_CONSTEXPR to facilitate testing. Update 3 fixes the expression SFINAE issues that were causing most of the Boost develop test failures. https://blogs.msdn.microsoft.com/vcblog/2016/06/07/expression-sfinae-improv… Quoting from that: There are still three failing tests in the Boost [develop] test suite when compiling with MSVC. Two test failures relate to using the noexcept operator in a template type argument. We currently parse it immediately, even in a dependent context. One test failure is a Boost library issue that we’ve reported to the [library's] maintainers. There are still known update 3 expression SFINAE issues (see "What remains to be done?" in the blog article) so do we continue to define BOOST_NO_SFINAE_EXPR? There is an undocumented BOOST_MSVC_SFINAE_EXPR macro in develop that turns off BOOST_NO_SFINAE_EXPR, so it is easy for developers to use msvc expression SFINAE if the want to. But our usual criteria for a _NO_ macro is not full compliance, but whether or not Boost code works with a feature. So using that criteria for update 3 we would remove BOOST_NO_SFINAE_EXPR. Opinions? --Beman <aside> We always urged Microsoft to test their releases against Boost. For update 3 expression SFINAE, they did exactly that. Thanks to Microsoft's Andrew Pardoe for coordinated the effort and to Xiang Fan for running the tests and tracking down the reason for each test failure. An undocumented Boost.Config macro BOOST_MSVC_SFINAE_EXPR to support their testing. The approach was to run tests for all libraries with the normal test setup, and then run again with BOOST_MSVC_SFINAE_EXPR defined. If the problem was with the Boost library, Xiang then reported it to me. I need to review a long series of email exchanges with him to make sure I alerted library maintainers to any Boost problems. </aside>

5 9

Boost Best Practice text download option fails.
by Fletcher, John P 08 Jun '16

08 Jun '16

This is a very interesting item to me. https://svn.boost.org/trac/boost/wiki/BestPracticeHandbook This has an option at the end to download as plain text. This fails on my browser (Firefox) with "Corrupted Content Error" which I have never seen before. Please sort this out someone. John

2 1

[variant] spirit broken
by Jürgen Hunold 08 Jun '16

08 Jun '16

Hi Antony, according to git bisect, your commit ----------- commit b3650685f941a0c35cadfd878a185f274e132788 Author: Antony Polukhin <antoshkka(a)gmail.com> Date: Sat May 28 01:29:52 2016 +0300 Variant constructors and assignment operators now do not participate in overload resolutions if variant can not hold the input type (trac 5871, trac 11602) ------------ broke Boost.Spirit. The test failures can be seen in the regression matrix. For example: http://www.boost.org/development/tests/develop/developer/output/Flast-FreeB… fails with ../boost/variant/variant.hpp:1152:7: note: while substituting deduced template arguments into function template 'operator=' [with T = boost::variant<boost::spirit::info::nil_, std::__1::basic_string<char>, boost::recursive_wrapper<boost::spirit::info>, boost::recursive_wrapper<std::__1::pair<boost::spirit::info, boost::spirit::info> >, boost::recursive_wrapper<std::__1::list<boost::spirit::info, std::__1::allocator<boost::spirit::info> > > >] class variant ^ ../boost/spirit/home/support/info.hpp:29:12: note: definition of 'boost::spirit::info' is not complete until the closing '}' struct info It seems that the commit somehow disabled support for recursive variant usage. To reproduce this, just run the Spirit regression test. Yours, Jürgen -- * Dipl.-Math. Jürgen Hunold ! * voice: ++49 4257 300 ! Fährstraße 1 * fax : ++49 4257 300 ! 31609 Balge/Sebbenhausen * jhunold(a)gmx.eu ! Germany

2 5

[Spirit] real_policies<> and 1.0#NAN
by Pete Bartlett 08 Jun '16

08 Jun '16

Hi, Boost.Spirit is not sure of itself when it comes to parsing representations of infs and nans such as “1.0#NAN”. The docs [1] for the default real_policies<T> for parsing numbers say: “[…] with the additional detection of NaN and Inf as mandated by the C99 Standard and proposed for inclusion into the C++0x Standard: nan, nan(...), inf and infinity (the matching is case-insensitive). This corresponds to the following grammar:” The first sentence suggests that 1.0#NAN etc will not be parsed. But the grammar itself then says: <quote> nan = -lit("1.0#") >> no_case["nan"] >> -('(' >> *(char_ - ')') >> ')') ; inf = no_case[lit("inf") >> -lit("inity")] ; </quote> suggesting that "#1.0NAN" is intended to parsed, but "#1.0INF" is not! Then the in-code docs [2] however suggest that both "1.0#NAN" and "1.0#INF" are intended to be parsed: <quote> // The second call allows to recognize representation formats starting // with a 1.0 (such as 1.0#NAN or 1.0#INF etc.). </quote> However, the actual code fails to parse either of these these. This is because in [3] the presence of the "0" causes frac_digits to be non-zero and so the "traits::is_equal_to_one(..)" condition is never tested. In the case "1.#NAN" (without a zero) frac_digits is zero so the condition is tested and we enter the traits::parse_nan code, but now the text parsed to this sub-parser is "#NAN" and the parser does not cater for the initial "#". Could the maintainers state which behaviour is intended...hopefully I may be able to supply a patch to docs/code/tests knowing that. Regards, Pete [1] http://www.boost.org/doc/libs/1_61_0/libs/spirit/doc/html/spirit/qi/referen… [2] <boost/spirit/home/qi/numeric/real_policies.hpp> [3]<boost/spirit/home/qi/numeric/detail/real_impl.hpp>

2 1

RFC : About forking a C++11 standard library and adapt it to C++98 compilers
by Vicente J. Botet Escriba 07 Jun '16

07 Jun '16

Hi, Some of us have to work yet with C++98 compiler at work (due to well know reasons) and this for a long time. This is a reality. I was wondering about forking a public domain C++11/14/17 standard library and adapt it to C++98 compilers. This library could be seen as another TR1, an extension of the C++03 standard library. Does this make any sens? Would this project be of interest for the Boost/C++ community? I have not a clear idea of the cost of doing this work, how it should be done, what would be the limitations, ... but I'm sure that this would be quite useful on the projects that are forced to use C++98 and an excellent bridge to those that will move from C++98 to C++11 compilers. There are some Boost libraries that could be used to reduce the limitations, as Boost.Config/Predef, Boost.Move, ...and others that could be used as inspiration on how to implement them using C++98. Anyway, if you find that this will be useful to you at your work we will need your participation. Would you be interested in working on it? as a Boost community project? outside Boost, as an independent project? Comments and suggestion welcome. Best, Vicente P.S. The same can be done for C++14 standard libraries and the future standard C++17 libraries P.S.S. The same can be done for C++14 libraries and the future C++17 libraries but this time adapting to C++11 compilers (this will be much easier but the concerned community will be quite different ).

5 7

Make libs/maintainers.txt a template file
by Daniel James 07 Jun '16

07 Jun '16

Hi, If you haven't noticed, on develop libs/libraries.htm is now a template which gets filled in as part of the documentation build. You can see the template and generated files at: https://github.com/boostorg/boost/blob/develop/libs/libraries.htm http://www.boost.org/doc/libs/develop/libs/libraries.htm This will be merged to master pretty soon. The only obstacle is updating the website automatically from the latest build, which should be happening very soon. The file libs/maintainers.txt is also automatically updated, but that's done in the repo itself, so that you have the full copy in you normal checkout. But I'm finding that people don't realise this, and we've had a few pull requests to update it manually. So instead, I think it might be a good idea to convert it to a template as well. This means you won't have a local copy, but will still be able to see a reasonably up to date copy online at: http://www.boost.org/doc/libs/develop/libs/maintainers.txt Any objections? I'm think of using similar templates for some other files, such as the root index.html (for the version number and new libraries). thanks, Daniel

2 2

Cxx dual library
by Edward Diener 06 Jun '16

06 Jun '16

I have finished all the main work on the Cxx dual library at https://github.com/eldiener/cxx_dual. The library is also in the Boost Library Incubator at http://rrsd.com/blincubator.com/bi_library/cxx_dual-2/?gform_post_id=1597. The Cxx dual library, or CXXD for short, is a C++ macro header-only library which chooses between using a Boost library or its C++ standard equivalent library for a number of different C++ implementations, while using the same code to program either choice. An 'implementation' is a Boost library which has a C++ standard library equivalent whose public interfaces are nearly the same in both cases. An 'implementation' is called a 'dual library' in this documentation, or 'CXXD-mod' for short. The library does this by defining object-like macros for including the appropriate header file and namespace or using either the Boost library version or the C++ standard library version of a particular dual library. CXXD currently supports twenty eight different dual libraries, where the Boost version and the C++ standard version is nearly interchangeable in some respects. CXXD also provides a macro-based solution for distinguishing between the Boost version and the C++ standard version of a dual library so that specific code for a particular dual library choice may be written in those cases where the public interfaces diverge. The library came out of my initial PR to add such a feature to Boost.Config, and then I decided to create a separate library and expand on the functionality. The gist of the library is to write a single set of code for a particular implementation and have it work whether or not that code targets a Boost implementation or its C++ standard equivalent. The default algorithm will choose the C++ standard implementation if it is available, otherwise it chooses the Boost implementation. The default can be overriden for any of the 28 different implementations which CXXD supports. With all the talk about supporting C++11 or C++14 in new code, the library offers a way of supporting C++11 or C++14 standard libraries if available whether one writes in C++03 dialect or uses the new language features of C++11 on up. The Cxx dual library itself, being macro based, should work with any C++ code at that code's language level. The library itself is NOT, repeat NOT, an attempt to enforce a C++ language level for anybody who wants to use it. I have a little more work I am doing on increasing the support for Boost Build in the library, but all the central implementation of the library is complete in my mind. Questions, comments, or bug reports are always welcome, either here in this mailing list, in the Boost Library Incubator, or as Github issues, by those who are interested in trying the library out or reading the documentation. I will be using CXXD in another library on which I am working but hopefully others will find a use for it in their own code.

5 30

[exception] Broken in master?
by John Maddock 06 Jun '16

06 Jun '16

Anything that includes Boost.Exception is currently broken on master for all compilers, for example: http://www.boost.org/development/tests/master/developer/output/teeks99-09j-… http://www.boost.org/development/tests/master/developer/output/Flast-FreeBS… The cause is the use of a partial-template specialization in info.hpp with no previous definition of class set_info_rv. Thanks, John.

2 1

Boost.Fiber mini-review May 23 - June 1: review report
by Nat Goodspeed 05 Jun '16

05 Jun '16

The Boost.Fiber mini-review is now closed. Results: Bjorn Reese: YES Niall Douglas (private): YES Agustín K-ballo Bergé: YES Niall Douglas reminds me that in a previous mini-review he already voted to accept the Fiber library. Unless he stated that he had changed his mind, it would be reasonable to carry forward that "yes" vote. However, he did reaffirm his previous stance. In that spirit, let me remind the community of another couple previous positive votes: Eugene Yakubovich Antony Polukhin Significantly, there were no remaining NO votes. I therefore conclude that the Boost community ACCEPTS the Fiber library into the Boost family of libraries. On behalf of the Boost community, I would like to congratulate Oliver Kowalke not only for his engineering work, but for considerable patience in working to improve the library and its documentation. Thank you, Oliver!

3 2

Re: [boost] Checking interest in std::get for PODs
by Bjorn Reese 04 Jun '16

04 Jun '16

On 06/03/2016 08:27 AM, Antony Polukhin wrote: > There's a C++14 library that is able to do basic reflections for PODs > without any macro magic or markup: https://github.com/apolukhin/magic_get Could the "Enums will be returned as their underlying type" limitation be partially worked around by allowing users to register their own enums?

3 2

Checking interest in std::get for PODs
by Antony Polukhin 04 Jun '16

04 Jun '16

Hi, There's a C++14 library that is able to do basic reflections for PODs without any macro magic or markup: https://github.com/apolukhin/magic_get Would it be interesting for Boost? Could it pass Boost review if it has a reinterpret_cast in it? -- Best regards, Antony Polukhin

8 16

Re: [boost] Cxx dual library
by Thomas Heller 04 Jun '16

04 Jun '16

Am 02.06.2016 8:56 nachm. schrieb "Edward Diener" <eldiener(a)tropicsoft.com>: > > I have finished all the main work on the Cxx dual library at https://github.com/eldiener/cxx_dual. The library is also in the Boost Library Incubator at > http://rrsd.com/blincubator.com/bi_library/cxx_dual-2/?gform_post_id=1597. > > The Cxx dual library, or CXXD for short, is a C++ macro header-only library which chooses between using a Boost library or its C++ standard equivalent library for a number of different C++ implementations, while using the same code to program either choice. An 'implementation' is a Boost library which has a C++ standard library equivalent whose public interfaces are nearly the same in both cases. An 'implementation' is called a 'dual library' in this documentation, or 'CXXD-mod' for short. > > The library does this by defining object-like macros for including the appropriate header file and namespace or using either the Boost library version or the C++ standard library version of a particular dual library. CXXD currently supports twenty eight different dual libraries, where the Boost version and the C++ standard version is nearly interchangeable in some respects. CXXD also provides a macro-based solution for distinguishing between the Boost version and the C++ standard version of a dual library so that specific code for a particular dual library choice may be written in those cases where the public interfaces diverge. Personally, I'm not a big fan of such a solution, especially when those macros "leak" into the public interface. We had a similar interface which would automatically switch between std and boost function. The result looked nice at first sight, however the subtle differences between the two led to various problems, one of which was that documenting the public interfaces containing this macro was very difficult, where does it point to know? Where should we send users to who look for more information about this function type? Should they be aware of both? Switching compilers or even boost version and now suddenly everything seems broken? The solution for us was to just decide which one to use and go with it, setting the requirements to the used standard library/boost version as needed.

4 9

A retrospect on 'CMakeLists.txt' policy review
by David Sankel 04 Jun '16

04 Jun '16

Hello all, I wanted to thank everyone who participated in the CMakeLists.txt and related threads. I'm sorry I wasn't able to participate all the way through, but I found the majority of the posts to be civil and constructive (some of my own heated posts being notable exceptions). Here is my take away. No one is arguing that the current guidelines disallow authors from placing a CMakeLists.txt in the root of their library's directory. Some pointed out drawbacks of placing them there and recommended 'build/' or 'CMake/' instead. Others saw value in having CMakeLists.txt in the root directory, but felt these should be short wrappers where the real work is done in the 'build/' directory. Louis and Paul, I know you felt it important for your gitHub distribution to have 'CMakeLists.txt' in the root directory as is typical for CMake projects. Does this result satisfy your concerns? -- David Sankel

9 18

[announcement] GitHub permission changes
by Daniel Pfeifer 03 Jun '16

03 Jun '16

Hi all, GitHub finally allows us to set permissions on the level of granularity that we always wanted. When we moved to GitHub, we received many request like "can I please get admin rights to my repository?" We wanted to do that, but it just was not possible. As a workaround, we have created a team per repository and many of those teams had just one member. That way, we could at least give you write access to individual repositories. Not quite what you requested, but at least something. Anyway, it is now possible to set permissions on a per repository level. I have started to delete the teams with a single member and added the member as the owner of the repository. How do those changes affect you? As the owner of a repository you have write access as before, but you can also add collaborators, modify the repository descriptions, enable/disable issue tracking and wiki, and so forth. I will continue this cleanup soon, but I need your input. For teams with multiple members, I don't know whether you want to share ownership or whether you prefer to have a single owner and additional contributors. Please create new issues for that matter: https://github.com/boostorg/admin/issues Cheers, Daniel

3 2

Boost.Fiber mini-review May 23 - June 1
by Nat Goodspeed 02 Jun '16

02 Jun '16

Hi all, The Boost.Fiber candidate library by Oliver Kowalke begins a mini-review today, Monday May 23, which will close Wednesday June 1. It was last reviewed in September 2015; the verdict at that time was "not yet." Oliver has been working steadily to address review comments and to improve the library in other ways, and has brought the library back for mini-review. The updated documentation is here: http://olk.github.io/libs/fiber/doc/html/index.html The code is on the master branch of this repository: https://github.com/olk/boost-fiber/tree/master I believe it is Oliver's intention to respond to review feedback on the develop branch, leaving the master branch stable during the review. 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 the subject line of your mail, e.g. by replying to this message. (Please reply to only ONE list, however.) I will also check the Boost Library Incubator for Fiber reviews: http://rrsd.com/blincubator.com/bi_library/fiber/?gform_post_id=859 though I check that less frequently than email. Please do remember to state in your review whether you think the library should be accepted as a Boost library. Thank you for your interest and your feedback! ----------------------------------------------------- Here follows a synopsis of issues raised during the September 2015 review: Cross-thread fiber migration: Evidently the community strongly desires the ability to transfer a suspended fiber from one thread to another. Now supported, with documentation. Cross-thread migration support implies a requirement to document the thread safety requirements of the customization API. Addressed. Standard required timing specifications: meet (30.2.4 Timing specifications [thread.req.timing]). Addressed. Adapt one or more existing test suites for thread facilities to validate the correctness of the Fiber library's synchronization constructs. The requester clarified in private mail that I misstated his suggestion: he wanted Oliver to review one or more such test suites to discover the kinds of issues that can arise with thread synchronization constructs. He has professed himself satisfied with the current state of the Fiber library's synchronization constructs. std::chrono support: ensure that wait_until() can accept any supported time_point specialization. Addressed. C++11 compatibility. Addressed. 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. Addressed. 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. Addressed. Avoid holding mutex during condition_variable::notify_*() calls. Addressed. packaged_task must not decay-copy its task arguments. Addressed. Align fibers::async() signature, result description and invoke_helper implementation with std::async(). Avoid returning std::move(...). Addressed. Wait list implementation: try an intrusive linked list of fiber_context objects. Addressed. Avoid sleeping thread when no fibers are ready -- block on external event. Better handling of waiting tasks (decentralized wait queues?). Addressed. Optimization to resume awakened fiber on the thread that awakens it. Hooks provided. 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. Addressed. Leverage predicate-based condition::wait() overload internally. Addressed. Nested schedulers: make schedulers be schedulable entities themselves. Not implemented. Improve robustness of `promise' handling in Asynchronous Callbacks documentation. Avoid overconfident remarks about it. Addressed. Fix Note overstating the requirements on condition_variable::wait(). Addressed.

2 3

[optional] using name boost::in_place -- need your opinion/advice
by Andrzej Krzemienski 30 May '16

30 May '16

Hi Everyone, I have stumbled upon a problem that I do not know how to address. I would like to seek an advice from the people in this list. I am trying to make boost::optional resemble std::optional (where it is reasonably easy to achieve). std::optional has this nice and useful "placement" constructor: std::optional<std::mutex> m {std::in_place}; std::in_place is a tag type, that instructs std::optional to create an object using placement-new syntax, from the provided arguments (zero in the example), without incurring any move construction. I cannot easily copy 1-to-1 this solution, because in namespace boost name in_place is reserved for the in-place factories: http://www.boost.org/doc/libs/1_61_0/libs/utility/in_place_factories.html I could simply go with a different name for a tag, but something tells me it would introduce an unnecessary complications for users that want to migrate from one optional to another. I could hack in-place factories so that they can also be used as a tag, although, I am not sure it is doable in a type-safe manner, and if it would not confuse people to have this boost::in_place do a number of different things. I could use a different namespace, but again, this might look surprising.I am a bit torn. I wonder if anyone here needed to face a similar problem, and if you can think of an elegant solution. Thanks, &rzej

4 12

[Boost.Test][Boot.Timer v2] header only boost.test conflicts with Boot.Timer V2
by Tan, Tom (Shanghai) 30 May '16

30 May '16

This following simple snippet would yield an error with visual studio 2015 for both boost1.60.61: boost/timer/timer.hpp(32): error C2757: 'timer': a symbol with this name already exists and therefore this name cannot be used as a namespace name // compiled with cl.exe /EHsc #define BOOST_TEST_MODULE test #include <boost/test/included/unit_test.hpp> #include <boost/timer/timer.hpp> The following variants are ok // compiled with cl.exe /EHsc #define BOOST_TEST_MODULE test #include <boost/test/unit_test.hpp> #include <boost/timer/timer.hpp> Or // compiled with cl.exe /EHsc #define BOOST_TEST_MODULE test #include <boost/test/included/unit_test.hpp> #include <boost/timer.hpp> It looks like Boost.Test is relying on boost.timer v1, which is deprecated in documentation and conflict with V2.

3 2

[boost.timer v2] auto_cpu_timer does not compile
by Tan, Tom (Shanghai) 29 May '16

29 May '16

This following snippet generates an error with VS2015 both fo 1.60&1.61: libboost_timer-vc140-mt-s-1_61.lib(cpu_timer.obj) : error LNK2019: unresolved external symbol "public: static class boost::chrono::time_point<class boost::chrono::steady_clock,class boost::chrono::duration<__int64,class boost::ratio<1,1000000000> > > __cdecl boost::chrono::steady_clock::now(void)" (?now@steady_clock@chrono@boost@@SA?AV?$time_point@Vsteady_clock@chrono@boost@@V?$duration@_JV?$ratio@$00$0DLJKMKAA@@boost@@@23@@23@XZ) referenced in function "public: struct boost::timer::cpu_times __cdecl boost::timer::cpu_timer::elapsed(void)const " (?elapsed@cpu_timer@timer@boost@@QEBA?AUcpu_times@23@XZ) // compile with cl.exe /EHSc #include <boost/timer/timer.hpp> int main() { boost::timer::auto_cpu_timer t; } What's interesting is that uncommenting line #14 in file boost/timer/timer.hpp would get rid of this error. - Why is there such a line but commented out there? - Is there a better way to get it through without modifying this file - the binary is downloaded from sourceforge, not a custom build. - Thanks.

1 0

Re: [boost] Boost.Fiber mini-review May 23 - June 1
by Bjorn Reese 28 May '16

28 May '16

On 05/23/2016 06:20 PM, Nat Goodspeed wrote: > Please do remember to state in your review whether you think the > library should be accepted as a Boost library. Yes, I vote for unconditional acceptance of Boost.Fiber. I did not participate in the formal review (due to time constraints), so I am not going to address the individual issues. I happened to have studied Boost.Fiber recently because I came across limitations of the inter-coroutine interaction in Boost.Coroutine, and Boost.Fiber addresses these limitations rather nicely. I especially like the message passing channels, which makes Boost.Fiber an obvious choice for building a coroutine-based actor framework. The only finding I have is that several Boost.Fiber headers include detail headers from Boost.Context. While this is not a problem per se (because Oliver is the maintainer of both libraries), it may be an idea to consider if these detail headers should be made public.

1 0

[iterator] strided, recursive variants
by Jeremy Murphy 28 May '16

28 May '16

Dear Boosters, I was wondering why a strided iterator has not made it into the Boost.Iterator library? There is a strided range in Boost.Range based on a private implementation of such an iterator, and Boost.Compute has their own implementation too. Just an untied loose end? On a related note, what about variants of such iterators that work in recursive algorithms? That is, if you stride a strided iterator, existing implementations will keep nesting the stride type, which the compiler fails to do recursively because there is no stopping criterion. So I wrote a variant of strided iterator that when you stride a strided iterator, it just multiplies the two strides together and takes the base pointer type from the original strided iterator. I assume some of the other iterator adaptors are limited in the same way. Anyway, it's no big deal to me, but I just thought I'd canvas whether that's something people (especially the maintainers) are interested in? Cheers. Jeremy

1 0

compiling mysql-5.7.12, cannot use DTRACE
by Mariano Apilado 26 May '16

26 May '16

Hi, I get the following error when compiling mysql-5.7.12 on Nexenta 4.0.4 OS ( Formerly known as Open Solaris / Illumos ). To temporarily bypass this problem, I chose not to use DTRACE with the compiler options. However, it should be fixed to use DTRACE. # cmake -DENABLE_DTRACE=0 Thanks and Regards,Mariano [ 15%] Linking CXX static library libmysys_ssl.a cd /usr/local/mysql-5.7.12/mysys_ssl && /usr/local/bin/cmake -P CMakeFiles/mysys_ssl.dir/cmake_clean_target.cmake cd /usr/local/mysql-5.7.12/mysys_ssl/CMakeFiles/mysys_ssl.dir && /usr/local/bin/cmake -DDTRACE=/usr/sbin/dtrace -DOUTFILE=/usr/local/mysql-5.7.12/mysys_ssl/CMakeFiles/mysys_ssl.dir/mysys_ssl_dtrace.o -DDFILE=/usr/local/mysql-5.7.12/include/probes_mysql.d -DDTRACE_FLAGS=-64 -DDIRS=. -DTYPE=STATIC_LIBRARY -P /usr/local/mysql-5.7.12/cmake/dtrace_prelink.cmake dtrace: failed to link script /usr/local/mysql-5.7.12/include/probes_mysql.d: No probe sites found for declared provider cd /usr/local/mysql-5.7.12/mysys_ssl && /usr/local/bin/cmake -E cmake_link_script CMakeFiles/mysys_ssl.dir/link.txt --verbose=1 /usr/bin/ar qc libmysys_ssl.a CMakeFiles/mysys_ssl.dir/crypt_genhash_impl.cc.o CMakeFiles/mysys_ssl.dir/mf_tempdir.cc.o CMakeFiles/mysys_ssl.dir/my_default.cc.o CMakeFiles/mysys_ssl.dir/my_getopt.cc.o CMakeFiles/mysys_ssl.dir/my_aes.cc.o CMakeFiles/mysys_ssl.dir/my_sha1.cc.o CMakeFiles/mysys_ssl.dir/my_sha2.cc.o CMakeFiles/mysys_ssl.dir/my_md5.cc.o CMakeFiles/mysys_ssl.dir/my_rnd.cc.o CMakeFiles/mysys_ssl.dir/my_murmur3.cc.o CMakeFiles/mysys_ssl.dir/my_aes_yassl.cc.o /usr/bin/ranlib libmysys_ssl.a cd /usr/local/mysql-5.7.12/mysys_ssl && /usr/bin/ar r /usr/local/mysql-5.7.12/mysys_ssl/libmysys_ssl.a /usr/local/mysql-5.7.12/mysys_ssl/CMakeFiles/mysys_ssl.dir/mysys_ssl_dtrace.o ar: cannot open /usr/local/mysql-5.7.12/mysys_ssl/CMakeFiles/mysys_ssl.dir/mysys_ssl_dtrace.o: No such file or directory ar: /usr/local/mysql-5.7.12/mysys_ssl/CMakeFiles/mysys_ssl.dir/mysys_ssl_dtrace.o not found gmake[2]: *** [mysys_ssl/libmysys_ssl.a] Error 1 gmake[2]: *** Deleting file `mysys_ssl/libmysys_ssl.a' gmake[2]: Leaving directory `/usr/local/mysql-5.7.12' gmake[1]: *** [mysys_ssl/CMakeFiles/mysys_ssl.dir/all] Error 2 gmake[1]: Leaving directory `/usr/local/mysql-5.7.12’ gmake: *** [all] Error 2

2 1

Call for Papers for Meeting C++ 2016 ends on Friday night!
by Jens Weller 25 May '16

25 May '16

Hello Boost Community! a short reminder, that the deadline is coming up for submitting your talk to this years Meeting C++ conference! Meeting C++ 2016 Page: http://meetingcpp.com/index.php/mcpp2016.html Talk submission page: https://meetingcpp.com/mcpp/submittalk/ thanks, Jens Weller

1 0

Error while compiling mysql-5.7.12 /usr/xpg4/include/term.h:596: error: conflicting types for ‘tgoto’
by Mariano Apilado 25 May '16

25 May '16

Hi, I get the following error when compiling mysql-5.7.12 on Nexenta 4.0.4 OS ( Formerly known as Open Solaris / Illumos ). In order to temporarily bypass this problem, I commented out. However, this is not the solution. /usr/local/mysql-5.7.12/cmd-line-utils/libedit/terminal.c:60: /* *#ifdef HAVE_CURSES_H *#include <curses.h> *#elif HAVE_NCURSES_H *#include <ncurses.h> *#endif */ Thanks and Regards,Mariano Error: [ 4%] Building C object cmd-line-utils/libedit/CMakeFiles/edit.dir/terminal.c.o cd /usr/local/mysql-5.7.12/cmd-line-utils/libedit && /usr/bin/gcc -DHAVE_CONFIG_H -D_FILE_OFFSET_BITS=64 -D_POSIX_PTHREAD_SEMANTICS -D_PTHREADS -D_REENTRANT -D__EXTENSIONS__ -I/usr/local/mysql-5.7.12/cmd-line-utils/libedit -I/usr/local/mysql-5.7.12/include -I/usr/local/mysql-5.7.12/extra/rapidjson/include -I/usr/local/mysql-5.7.12/libbinlogevents/include -I/usr/local/mysql-5.7.12/libbinlogevents/export -I/usr/xpg4/include -m64 -O3 -g -fabi-version=2 -fno-omit-frame-pointer -fno-strict-aliasing -DDBUG_OFF -fPIC -m64 -lstdc++ -R'RIGIN/../lib' -R/usr/lib/amd64 -o CMakeFiles/edit.dir/terminal.c.o -c /usr/local/mysql-5.7.12/cmd-line-utils/libedit/terminal.c In file included from /usr/xpg4/include/curses.h:43, from /usr/local/mysql-5.7.12/cmd-line-utils/libedit/terminal.c:60: /usr/xpg4/include/term.h:596: error: conflicting types for ‘tgoto’ /usr/local/mysql-5.7.12/cmd-line-utils/libedit/sys.h:137: note: previous declaration of ‘tgoto’ was here gmake[2]: *** [cmd-line-utils/libedit/CMakeFiles/edit.dir/terminal.c.o] Error 1 gmake[2]: Leaving directory `/usr/local/mysql-5.7.12' gmake[1]: *** [cmd-line-utils/libedit/CMakeFiles/edit.dir/all] Error 2 gmake[1]: Leaving directory `/usr/local/mysql-5.7.12’ gmake: *** [all] Error 2

1 0

Having problems installing mysql 5.7.12 with boost ELF 32 bit, wrong ELF Class
by Mariano Apilado 25 May '16

25 May '16

Hi, I get the following error when compiling mysql-5.7.12 on Nexenta 4.0.4 OS ( Formerly known as Open Solaris / Illumos ). How do I fix the compile options or get the necessary files required to make the compile successful? Thanks and Regards, Mariano The files libboost_system.so and libboost_chrono.so are the wrong ELF class: ELFCLASS32. root@nex-01-test:/volumes# file /root/boost_1_59_0/stage/lib/libboost_system.so /root/boost_1_59_0/stage/lib/libboost_system.so: ELF 32-bit LSB dynamic lib 80386 Version 1, dynamically linked, not stripped, no debugging information available root@nex-01-test:/volumes# file /root/boost_1_59_0/stage/lib/libboost_system.so /root/boost_1_59_0/stage/lib/libboost_system.so: ELF 32-bit LSB dynamic lib 80386 Version 1, dynamically linked, not stripped, no debugging information available Error Message: [ 95%] Linking CXX executable ../mysqlpump cd /root/mysql-5.7.12/client/dump && /usr/local/bin/cmake -E cmake_link_script CMakeFiles/mysqlpump.dir/link.txt --verbose=1 /usr/bin/g++ -w -fpermissive -m64 -Wall -Wextra -Wformat-security -Wvla -Woverloaded-virtual -Wno-unused-parameter -O3 -g -fabi-version=2 -fno-omit-frame-pointer -fno-strict-aliasing -DDBUG_OFF -R'$ORIGIN/../lib' -R/usr/lib/amd64 CMakeFiles/mysqlpump.dir/program.cc.o -o ../mysqlpump libmysqlpump_lib.a -lboost_system -lboost_chrono ../base/libclient_base.a ../../libmysql/libmysqlclient.a -lsocket -lnsl -lm ../../extra/liblz4_lib.a ld: fatal: file /root/boost_1_59_0/stage/lib/libboost_system.so: wrong ELF class: ELFCLASS32 ld: fatal: file /root/boost_1_59_0/stage/lib/libboost_chrono.so: wrong ELF class: ELFCLASS32 ld: fatal: file processing errors. No output written to ../mysqlpump collect2: ld returned 1 exit status gmake[2]: *** [client/mysqlpump] Error 1 gmake[2]: Leaving directory `/root/mysql-5.7.12' gmake[1]: *** [client/dump/CMakeFiles/mysqlpump.dir/all] Error 2 gmake[1]: Leaving directory `/root/mysql-5.7.12’ gmake: *** [all] Error 2

2 1

[compute] [OS X 10.11.5] [GeForce GT 750M] Segmentation fault
by Prashant 25 May '16

25 May '16

Hi, Am trying to sort a vector on GPU (GeForce GT 750M) using example code which generates SEGV. However, it runs fine on Iris Pro (Intel(R) Core(TM) i7-4850HQ CPU). We observe SEGV when size is 10 million. When the size is 5 million, following exception is thrown: boost/1_61_0/include/boost/compute/command_queue.hpp(453): Throw in function boost::compute::event boost::compute::command_queue::enqueue_write_buffer(const boost::compute::buffer &, size_t, size_t, const void *, const boost::compute::wait_list &) Dynamic exception type: boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector< boost::compute::opencl_error> > std::exception::what: Invalid Value Another observation: if the size of vector is 50 million the sorting works fine, though the timings are worse than Iris Pro. Also, when is size is 100 million, the binary causes the OS to crash. Compiler details: clang++ --version Apple LLVM version 7.3.0 (clang-703.0.31) Target: x86_64-apple-darwin15.5.0 Thread model: posix OS: System Version: OS X 10.11.5 (15F34) Kernel Version: Darwin 15.5.0 Regards, Prashant ----------------------------Cut here------------------------------------- #include <iostream> #include <vector> #include <algorithm> #include <boost/foreach.hpp> #include <boost/compute/core.hpp> #include <boost/compute/platform.hpp> #include <boost/compute/algorithm.hpp> #include <boost/compute/container/vector.hpp> #include <boost/compute/functional/math.hpp> #include <boost/compute/types/builtin.hpp> #include <boost/compute/function.hpp> #include <boost/chrono/include.hpp> #include <boost/exception/all.hpp> namespace compute = boost::compute; int main(int argc, char* argv[]) { if (argc != 2) { std::cout << "Usage: " << argv[0] << " <size> " << std::endl; return 0; } // generate random data on the host std::vector<float> host_vector(atoi(argv[1])); std::generate(host_vector.begin(), host_vector.end(), rand); std::cout << "===============CPU==================\n"; for (size_t k=0; k<5; k++) { std::vector<float> host_copy_vector(host_vector); auto start = std::chrono::high_resolution_clock::now(); std::sort(host_copy_vector.begin(), host_copy_vector.end()); auto duration = std::chrono::duration_cast<std::chrono::milliseconds> (std::chrono::high_resolution_clock::now() - start); std::cout << "time: iteration ("<< k << ") : " << duration.count() << " ms" << std::endl; } std::vector<compute::platform> platforms = compute::system::platforms(); for(size_t i = 0; i < platforms.size(); i++){ const compute::platform &platform = platforms[i]; std::cout << "Platform '" << platform.name() << "'" << std::endl; std::vector<compute::device> devices = platform.devices(); for(size_t j = 0; j < devices.size(); j++){ const compute::device &device = devices[j]; std::string type; if(device.type() & compute::device::gpu) type = "GPU Device"; else if(device.type() & compute::device::cpu) type = "CPU Device"; else if(device.type() & compute::device::accelerator) type = "Accelerator Device"; else type = "Unknown Device"; if (type != "GPU Device") { std::cout << "Ignoring non GPU devices.\n"; continue; } std::cout << "====\n"; std::cout << " " << type << ": " << device.name() << std::endl; std::cout << "====\n"; compute::context context(device); compute::command_queue queue(context, device); for (size_t k=0; k<5; k++) { compute::vector<float> device_vector(host_vector.size(), context); // copy data from the host to the device compute::copy( host_vector.begin(), host_vector.end(), device_vector.begin(), queue ); auto start = std::chrono::high_resolution_clock::now(); try { compute::sort(device_vector.begin(), device_vector.end(), queue); } catch (boost::exception & e) { std::cerr << diagnostic_information(e); break; } auto duration = std::chrono::duration_cast<std::chrono::milliseconds> (std::chrono::high_resolution_clock::now() - start); std::cout << "time: iteration ("<< k << ") : " << duration.count() << " ms" << std::endl; } std::cout << "====\n"; } } return 0; }

2 1

[multiprecision] compilation failure
by Raffi Enficiaud 24 May '16

24 May '16

Hi, I have the following failure on develop from multiprecision (unit tests of boost.test): In file included from writing-test-ts/fp-multiprecision-comparison-test.cpp:23:0: ../../../boost/multiprecision/cpp_dec_float.hpp: In member function ?std::size_t boost::multiprecision::backends::cpp_dec_float<Digits10, ExponentType, Allocator>::hash() const?: ../../../boost/multiprecision/cpp_dec_float.hpp:264:10: error: ?hash_combine? is not a member of ?boost? boost::hash_combine(result, data[i]); Thanks, Raffi

3 2

Request for a "Policy Review" regarding 'CMakeLists.txt'
by David Sankel 24 May '16

24 May '16

A question has been brought up regarding whether or not a Boost library author is permitted to include a 'CMakeLists.txt' file in the root of the directory. This stemmed from a discussion at C++Now 2016 which included several members of the Boost Steering Committee and a sampling of the Boost community. We recommend and propose that the Boost Guidelines are modified to allow library authors, at their own discretion, to include a 'CMakeLists.txt' file in their library's top-level directory. * Several libraries, such as Boost.Hana and Boost.Spirit, have two distribution mechanisms: one as distributed with Boost and the other as an independent package. The requirement that these libraries not include a 'CMakeLists.txt' as part of their Boost distribution creates a maintenance burden for authors or otherwise hurts usability of the independent distribution. * Several companies have revealed that they are building Boost with their own custom CMake scripts. The suggested policy change would enable authors to relieve the infrastructure cost of their CMake users and unify how their library is built. * CMake is, by far, the most popular build system for C++. Allowing authors to support CMake users in addition to BJam will help the Boost ecosystem to grow and thrive by lowering the barriers to access. -- David Sankel

51 224

Boost.Fit review Mars 3-20 result
by Vicente J. Botet Escriba 24 May '16

24 May '16

Hi, I will be out for two weeks and I wanted to at least give the result of the Boost.Fit library review even if I would need more time to have a complete report. Summary ======= The review of the proposed Boost.Fit library ended on Mars 20, 2016. The verdict is: Conditional acceptance (a new review is needed) There were too much concerns about the documentation and what exactly this library is proposing and not enough reviews commenting the design, code and test for each one of the proposed functions. From the review discussion I deduce that there is some interest in the library, and that some people don't understand yet what the library is proposing. Paul has started already to take in account some if the issues raised during the review and a lot of them must be resolved before we re-try a new review. There were some discussion about the name of the library, but there were no consensus. Paul is free to change the name of his library and see how people react. On behalf of the Boost community, I would like to thank Paul Fultz for the work he has put into the Fit library so far. I encourage him to continue to evolve this library and to bring it back for a new review. We had seven 6 formal votes, and 2 more votes without a complete review abbreviated here: Steaven Watanabe: No in his current state Zach Laine : Conditinal acceptance Krzysztof Jusiak: Accepted Artyom Beilis : Rejected Peter Dimov : Accepted (no review) Manuel Sancher : Accepted (no review) Rob Stewart : Conditinal acceptance ??? Louis Dionne : Conditinal acceptance There were other people that participated on the review giving their advice respect to a specific issue. I thank each of these reviewers, and indeed everyone who invested some time participating in the discussions. If you feel that I have misrepresented your position, or have omitted or garbled an important point, please respond: the archived mail thread should accurately reflect the will of the community, even if this message does not. Detailed Report =============== You will need to wait yet for a month before I will be able to do it. On the mean time there are a lot of issues that must be addressed and that are part of the github issues. For more information see: Github:https://github.com/pfultz2/Fit/tree/boost Issues:https://github.com/pfultz2/Fit/issues Documentation:http://pfultz2.github.io/Fit/doc/html/ Hopping this helps, Vicente Botet Escriba

11 26

b2 looks for tools/inspect/build/Jamfile
by Peter Dimov 23 May '16

23 May '16

I'm experimenting with a partial Boost clone, the superproject, tools/build, libs/bind, libs/config and few others, and when trying to build the tests, I'm getting the following error: D:\tmp\boost\libs\bind\test>..\..\..\b2 toolset=msvc-10.0 D:/tmp/boost/tools/build/src/build\project.jam:262: in find-jamfile from module project error: Unable to load Jamfile. error: Could not find a Jamfile in directory '../../../tools/inspect/build'. error: Attempted to find it with pattern '[Bb]uild.jam [Jj]amfile.v2 [Jj]amfile [Jj]amfile. [Jj]amfile.jam'. error: Please consult the documentation at 'http://www.boost.org'. D:/tmp/boost/tools/build/src/build\project.jam:280: in load-jamfile from module project D:/tmp/boost/tools/build/src/build\project.jam:64: in load from module project D:/tmp/boost/tools/build/src/build\project.jam:89: in load-used-projects from mo dule project D:/tmp/boost/tools/build/src/build\project.jam:75: in load from module project D:/tmp/boost/tools/build/src/build\project.jam:113: in load-parent from module p roject D:/tmp/boost/tools/build/src/build\project.jam:464: in initialize from module pr oject D:/tmp/boost/tools/build/src/build\project.jam:306: in load-jamfile from module project D:/tmp/boost/tools/build/src/build\project.jam:64: in load from module project D:/tmp/boost/tools/build/src/build\project.jam:113: in load-parent from module p roject D:/tmp/boost/tools/build/src/build\project.jam:464: in initialize from module pr oject D:/tmp/boost/tools/build/src/build\project.jam:306: in load-jamfile from module project D:/tmp/boost/tools/build/src/build\project.jam:64: in load from module project D:/tmp/boost/tools/build/src/build\project.jam:145: in project.find from module project D:/tmp/boost/tools/build/src\build-system.jam:535: in load from module build-sys tem D:\tmp\boost\tools\build\src/kernel\modules.jam:295: in import from module modul es D:\tmp\boost\tools\build\src/kernel/bootstrap.jam:139: in boost-build from modul e D:\tmp\boost\boost-build.jam:17: in module scope from module Does anyone have an idea why b2 looks for the tools/inspect Jamfile? I don't remember this being a problem before when I tried a stripped-down installation.

6 14

doctest - the lightest feature rich C++ single header testing framework - if it can enter boost and if it/boost will benefit from that
by Viktor Kirilov 23 May '16

23 May '16

Hello! I just released doctest - https://github.com/onqtam/doctest All the info about it can be found on github. So do you think it can enter the boost project? How much work will it take to get it into boost except for adding boost in the title? Will it or boost benefit from that addition? Also I've sort-of followed the Best Practice Handbook (I consider it very valuable) as much as possible - https://svn.boost.org/trac/boost/wiki/BestPracticeHandbook Any feedback will be greatly appreciated. Thanks!

10 19

Rebooting Boost: Call for Lightning Talks @ CppCon
by Niall Douglas 23 May '16

23 May '16

At C++ Now a number of informal meetings showed there to be frustrations with the current ecosystem around the Boost C++ Libraries (to paraphrase a founder of Boost, "Boost is supposed to serve *the entire C++ community; it isn't Boost's goal to serve Boost's community*". Recent and recurrent boost-dev discussions have raised the lack of cmake based tooling; lack of ABI management and the consequent ODR violation when mixing Boost versions in the same process; the anti-social behaviour of Boost towards library end users, new ideas, new blood and the wider C++ community; and the chronic lack of maintenance of up to half the Boost libraries. One question which needs to be answered is whether a clean reboot of Boost from the first principles of proving high quality C++ libraries well suited for use with the latest C++ standard is viable. This new collection of C++ libraries would be started completely from scratch (even if some existing libraries were ported into the new organisation), so ANYTHING is possible. All we need is a critical mass of library developers willing to collaborate on developing a shared infrastructure mutually beneficial to all participants, whether library developer or library end user. To that end of discovering if this critical mass is there, five minute lightning talk topics are requested for CppCon this September on this topic: "What design pattern, practice or idiom should a standards aspiring collection of C++ 14/17 libraries share?" Please keep each talk topic focused on a single design pattern, practice or idiom (see suggested talk format below). Each speaker may submit up to THREE talk topics (not all may be accepted if there are a lack of slots, so please rank them in order of preference). Please send your talk topics to me privately by email, only if sufficient numbers present to fill a session will your name and your talk topic be shared with the CppCon Programme Committee. We'll try to arrange a short panel session at the end so attendees can ask questions of the speakers. After the lightning talk we'll arrange a restaurant so all the speakers and any interested attendees can dine together, followed by a night in a Bellevue bar. If after the dust has settled it is felt there is a critical mass sufficient to reboot a brand shiny new edition of Boost, we'll start development! I should *stress* that it is up to the CppCon Programme Committee whether these lightning talks are approved or not. I'll just copy and paste your proposed talk to the CppCon PC as-is. If insufficient lightning talk topics are received by me to fill a 60 minute session, I'll withdraw this talk proposal from CppCon. Suggested talk format ================ Five minutes is not much time, so here is a suggested lightning talk outline: 1. A current widely practiced library design pattern (show example). 2. The problems it generates for library users or maintainers. 3. Your proposed alternative design pattern (show example). 4. The problems the alternative design pattern fixes. 5. Any mockup, prototype or even live demo (!) of the alternative design pattern in action. Suggested talk themes might be documentation, packaging, distribution, testing, tooling, quality assessment, barriers to entry, governance, strategy, important gaps in the standard libraries, automation and deprecation/removal policies. Here is an example of such a lightning talk: 1. Current design pattern: Library v1.00: namespace boost { namespace lib { void foo(size_t, char); } } User code: boost::lib::foo(100, 'n'); 2. Problem: Library v1.01: namespace boost { namespace lib { void foo(char, size_t); } } User code: boost::lib::foo(100, 'n'); // oh oh! 3. Alternative: Library v1.00: namespace boost { namespace lib { inline namespace v100 { void foo(size_t, char); } } } #define BOOST_LIB_NAMESPACE_V100 boost::lib::v100 Library v1.01: namespace boost { namespace lib { inline namespace v101 { void foo(char, size_t); } } } #define BOOST_LIB_NAMESPACE_V101 boost::lib::v101 User code: // Mount v100 of Boost.Lib into "lib" namespace lib=BOOST_LIB_NAMESPACE_V100; lib::foo(100, 'n'); // ABI stable! No ODR violation possible! 4. Problems fixed: a) Mixing incompatible versions of individual Boost libraries in the same process (or even translation unit) is now safe. b) Libraries can now depend on other libraries without worrying about breaking code which depends on them which uses a different version of the same dependency. This greatly helps reduce change ripple effects. c) Forward compatibility or alternative implementation shims are now very easy to implement e.g. library users can externally configure either Boost.Filesystem or std::experimental::filesystem for your library to use, your code simply refers to _some_ Filesystem TS implementation e.g. namespace filesystem = FILESYSTEM_TS_IMPLEMENTATION; filesystem::path mypath; -- ned Productions Limited Consulting http://www.nedproductions.biz/ http://ie.linkedin.com/in/nialldouglas/

8 10

@boost-admins: permission to git-repo removed?!
by Oliver Kowalke 23 May '16

23 May '16

Hi, I can't push commits to git-repo boost.coroutine2: remote: Invalid username or password. fatal: Authentication failed for 'https://github.com/boostorg/coroutine2/' Could you please re-add user 'olk', please. thx, Oliver

3 3

What C++14/1z standard or TS libraries would you like to have available on a C++11 compiler?
by Vicente J. Botet Escriba 23 May '16

23 May '16

Hi, I would like to have your feedback on C++ standard library features you would like to have available for a C++11 compiler. The idea would be to present a Boost.StdExtensions library that would provide some of these features for review with some of these features. Please , let me know if you are interested in participating in this project and working on some specific parts. This library should avoid as much Boost dependencies as possible. How the library could be structured? I believe that it should follow the C++ standard files. Which folder should be used? boost/stdext? boost/stdext11? Which namespace? boost::stdext? I have prefixed with a * the lines that interest myself and with VBE* those that I could work on. The features that need compiler help or that need C++14/17 language features are excluded and prefixed by N/A. Please be free to add a * if you are interested and your name as well if you want to participate. Best, Vicente P.S. The project could be as well extended to C++98 compilers with C++11 standard libraries (But I would not have time to invest in). P.S.S. I would also be interested in extend the project to extended to C++14 compilers. C++14 standard libraries ================ VBE* N3658 - Compile-time integer sequences * N3654 - Quoted Strings N3656 - make_unique VBE* N3462 - std::result_of and SFINAE * N3668 std::exchange() N3469 Constexpr Library Additions: chrono N3470 Constexpr Library Additions: containers N3471 Constexpr Library Additions: utilities N3302 Constexpr Library Additions: complex VBE* N3545 An Incremental Improvement to integral_constant N3644 Null Forward Iterators N3670 Addressing Tuples by Type N3671 Making non-modifying sequence operations more robust N3642 User-defined Literals VBE* N3655 TransformationTraits Redux (excluding part 4) N3657 Adding heterogeneous comparison lookup to associative containers N3669 Fixing constexpr member functions without const N3659 Shared Locking in C++ N3779 User-defined Literals for std::complex N3789 Constexpr Library Additions: functional N3887 Consistent Metafunction Aliases N3891 A proposal to rename shared_mutex to shared_timed_mutex C++1z standard libraries ================ VBE* N3911 TransformationTrait Alias void_t N4089 Safe conversions in unique_ptr<T[]> VBE* N4169 A proposal to add invoke function template N4258 Cleaning-up noexcept in the Library. N4277 TriviallyCopyable reference_wrapper. N4279 Improved insertion interface for unique-key maps. VBE* N4280 Non-member size() and more N4284 Contiguous Iterators. N4387 improving pair and tuple VBE* N4389 bool_constant N4508 shared_mutex for C++17 N4366 LWG 2228 missing SFINAE rule N4510 Minimal incomplete type support for standard containers N/A* P0006R0 Adopt Type Traits Variable Templates for C++17. VBE* P0092R1 Polishing <chrono> VBE* P0007R1 Constant View: A proposal for a std::as_const helper function template. VBE* P0156R0 Variadic lock_guard(rev 3). P0074R0 Making std::owner_less more flexible VBE* P0013R1 Logical type traits rev 2 P0024R2 The Parallelism TS Should be Standardized P0226R1 Mathematical Special Functions for C++17 VBE* P0220R1 Adopt Library Fundamentals V1 TS Components for C++17 P0218R1 Adopt the File System TS for C++17 P0033R1 Re-enabling shared_from_this VBE* P0005R4 Adopt not_fn from Library Fundamentals 2 for C++17 P0152R1 constexpr atomic::is_always_lock_free N/A* P0185R1 Adding [nothrow-]swappable traits P0253R1 Fixing a design mistake in the searchers interface P0025R0 An algorithm to "clamp" a value between a pair of boundary values P0154R1 constexpr std::hardware_{constructive,destructive}_interference_size P0030R1 Proposal to Introduce a 3-Argument Overload to std::hypot P0031R0 A Proposal to Add Constexpr Modifiers to reverse_iterator, move_iterator, array and Range Access P0272R1 Give std::string a non-const .data() member function VBE* P0077R2 is_callable, the missing INVOKE related trait Fundamental V1 TS ============ Uses-allocator construction Changes to std::shared_ptr and weak_ptr Additions to std::function Additions to std::promise Additions to std::packaged_task Class erased_type VBE* Calling a function with a tuple of arguments N/A Type traits (_v) Other type transformations Compile-time Rational Arithmetic Time Utilities System Error Support Class memory_resource Class template polymorphic_allocator Template alias resource_adaptor Global memory resources Pool resource classes Class monotonic_buffer_resource Alias templates using polymorphic memory resource Searchers * Optional Objects Initial implementation * class any * string_view memory Algorithms library

6 8

Boost 1.61.0 has been released
by Rene Rivera 22 May '16

22 May '16

Release 1.61.0 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 four new libraries and numerous enhancements and bug fixes for existing libraries. New Libraries * Compute: Parallel/GPU-computing library, from Kyle Lutz. * DLL: Library for comfortable work with DLL and DSO, from Renato Tegon Forti and Antony Polukhin * Hana: A modern C++ metaprogramming library, from Louis Dionne. * Metaparse: A library for generating compile time parsers parsing embedded DSL code as part of the C++ compilation process, from Abel Sinkovics. For details, including download links, see http://www.boost.org/users/news/version_1.61.0 You can also download directly from SourceForge: http://sourceforge.net/projects/boost/files/boost/1.61.0/ Tom Kent has made pre-built windows binaries, and they are available at: https://sourceforge.net/projects/boost/files/boost-binaries/1.61.0/ 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

11 18

Boost Evolution
by Robert Ramey 21 May '16

21 May '16

What I would like to see is more encouragement for the idea of boost evolution. But I have well defined ideas about how that should occur. I articulated these ideas is quite a bit of detail at C++Now in 2015 to a packed house. It wasn't recorded so you'll have to take my word for it. All is not lost though. For those who might be interested I kept my practice recordings for the narrative on the slides and attached them to each slide. So you can get a good feeling for the presentation by checking out http://www.blincubator.com/C++Now2015/index.html If you do this don't forget to checkout the last two slides (including the audio)! in real life it was much better!!! When I articulated my particular suggestions at the conference there was a lot of push back and I sort of lost control of things. On the other hand, there was a lot of enthusiasm for my "call to action". I didn't expect any drastic changes. But as I look back a year I do see some real progress. I see: a) more and better reviews b) more interest, discussion and criticism of documentation c) 30 libraries in the incubator. Some have already been added to boost. d) Now movement on opening up the build/test system to evolution. e) A program in place to make more resources available for maintaining existing libraries. The complains of unmaintained libraries have diminished by quite a bit - I don't know for a fact that this is related to this program - maybe it's just a happy coincidence. A couple of things have made much progress. a) modular deployment and dependency management. No surprise here as this is a job of major, major difficulty. b) policy for library deprecation - not really hard but really very low priority. c) improvements in incubator - no real progress - but it's probably as good as it needs to be. d) boost website improvement - no discernible progress. There is one big lesson from all this: a) Boost is not a company - we don't take direction from the top. b) Boost is not a government - we actually do something. c) Boost is a religion - want something changed, start preaching. Get other people on board. Convince people people to start doing something. Take a look at the CMake history. There was a huge effort undertaken from the top to switch to CMake for build / test. It was a failure because it tried to do it from the top down. I'm thinking that the promoters of this idea concluded that the problem wasn't ambitious enough and added deployment to the task and built rypll. This had as key collaborators our most capable and hard core developers - including David Abrahams and Eric Neibler. Huge amount of expended effort but not much came out of it. I think if you want to help boost evolve - remember Boost is a religion. We are the jesuits of C++. Bjarn's marines - the tip of the spear. We ambush the world with a new idea which builds or replaces something else. We do it in an insidious manner. The opening up to CMake has proceeded steadily over years until it's a the cusp of victory. No one saw it coming and here it is. The world doesn't change from great initiatives, it changes when the old order collapses while espending it's existence to deny change. I've been told on this is a right wing world view - and so it is - oh well. So I encourage those who want to contribute to Boost and by extension C++ to consider using this approach. I think you'll be more successful. Robert Ramey

19 47

A comment on cmake and subprojects
by Biddiscombe, John A. 20 May '16

20 May '16

In our task of the HBP (Human Brain Project), we have a lot of libraries with interdependencies and have standardised on a reasonably simple system that works well enough – it can/could be improved significantly, but in case it’s of interest to boost, here’s a brief description (which I’m writing from memory and all the actual names of commands etc are wrong, but I only aim to describe the process) A top level cmakelists file would contain something like project(my_big_project) add_subproject(subprojectX ${CMAKE_CURRENT_SOURCE_DIR}/x) add_subproject(subprojectY ${CMAKE_CURRENT_SOURCE_DIR}/y) etc subprojects X,Y,….. Are defined by either including the source for those projects in the relevant subdirs, or by providing an additional command along the lines of git_external_project(name URL branchname/SHA/etc) Or by supplying a .gitprojects file in the root of the master subproject (subproject can if they wish do this recursively) which may contain a list of desirable projects + urls that we know will be needed if enabled When the user runs cmake on the top-level source project (my_big_project) it provides OPTIONS of the form SUBPROJECT X ON/OFF SUBPROJECT Y ON/OFF Which the user can enable via the GUI or by cmake –DSUBPROJECT_X=ON …. The macros defined will decide that if project X is not present to do a git clone (--shallow, --branch, --anything you want to add in the config) of project X,Y,… from the git URL supplied and checkout the repo into the correct location, add_subproject then enters the subproject and cmake progresses as usual. Inside the subproject, another macro can defined DEPENDENCIES of the project via more instantiations of the same kind which will also be cloned as git subprojects if they are not already present (currently if X depends on A branch1 and Y depends on A branch2 we throw an error, but it would be possible to support this tight control of include_directories). Seeing the ongoing discussion of cmake in boost (I am one of the many it seems who cmakeified the parts of boost I needed years ago and then gave up around the time rypll came into being – hoping that the job would be done properly). So the top level boost cmakelists would simple contain a list of all the libraries and their git locations and release branches, each sub project (library) can say dependencies(atomic, filesystem, threads, context) and let the cmake scripts do the rest. A user checking out the “top” level boost would get only a single cmakelists file with a bunch of helper scripts containing the macros needed for install, versions, git cloning etc etc and would then run cmake –DSUBPROJECT_ATOMIC=ON –DSUBPROJECT_THREADS=ON –DSUBPROJECT_CONTEXT=ON ~/path/to/top/level/boost-cmakelists (you could change the SUBPROJECT to BOOSTMODULE or something like that if you preferred) If one of the libs the user ‘wants’ uses another library, it gets enabled by the dependencies declared in the lib and everything just builds and works. A make install will install all the libs that got built including those dependencies that were pulled in (some public/private options could no doubt be added to make that better if necessary). To give you an idea of what I’m referring to, https://github.com/Eyescale/CMake/blob/master/GitExternal.cmake<https://github.com/Eyescale/CMake/blob/master/SubProject.cmake> https://github.com/Eyescale/CMake/blob/master/SubProject.cmake Are a couple of scripts that do some of the work. The process has helped us to simplify somewhat our build and dependency process and it might be a useful mechanism for boost to use cmake. It isn’t perfect, isn’t pretty in some places and has been heavily tweaked beyond its original purpose so the scripts would not be considered usable in their current state – but with some cleaning up … One very nice feature is the one can create a simple script project(mystuff) #set some options we might beed set(boost_optionX,y,x…) add_subproject(boost) # and some more set(hpx_optionX,y,z…) add_subproject(hpx) set(my_optionX,y,z…) add_subproject(stuff_that_needs_them) And the user does not need to worry about cloning the projects as the gitproject refs will do it for them and take what’s needed on a per repo basis. (I use this for HPX extensively - the individual libs/projects must be careful with relative path names and using per project prefixes for options, tests etc etc) I would be happy to volunteer as a helper should you wish for help cmakeifying boost regardless of the method by which you proceed. JB -- John Biddiscombe, email:biddisco @.at.@ cscs.ch http://www.cscs.ch/ CSCS, Swiss National Supercomputing Centre | Tel: +41 (91) 610.82.07 Via Trevano 131, 6900 Lugano, Switzerland | Fax: +41 (91) 610.82.82

1 0

Files in individual libraries
by Edward Diener 20 May '16

20 May '16

As long as library authors follow the normal Boost guidelines for placing the necessary files for using, building ( for non-header only libraries ), testing, and documenting their library I really don't see why an author cannot add to their library whatever other files they want in whatever place in their library structure they want to put it. Can it really be such a big issue that this should not be allowed ? And, if so, why ? If the real issue being objected to is that the placement of additional files gives the end-user an impression that Boost libraries generally support additional things which an individual library supports with the additional files, wouldn't it just be better to encourage and/or require that an individual library developer document the additional files as personal extensions to what Boost requires.

2 2

Re: [boost] [Boost-users] Boost 1.61.0 has been released
by Daniel James 19 May '16

19 May '16

On 18 May 2016 at 08:05, Vladimir Prus <vladimir.prus(a)gmail.com> wrote: > > Tom has pointed a typo in file names in the file. Correct one is now > attached, and instructions > for validating are the same: I added the to the website, it's currently linked from the release notes, and if it's okay, I'll add a link to the download page at some point. Although it can't be underestimated just how little I care or understand about any of this stuff, so I'm sure I've done it all wrong. If line endings make a difference then it might not work since git converted the file to unix style automatically, so let me know. I also don't really want to add all the instructions to the release notes, so if someone wants to write generic instructions for another page, I could put that up and link to it.

1 0

DMARC and mailman
by James Sharpe 19 May '16

19 May '16

In June 2016 gmail is going to be changing its DMARC policy to reject any unaligned mail. This means that we will be seeing any mailing list responses from a gmail.com address to be considered spam by any mail server that enforces DMARC. For a while now yahoo.com has had this policy turned on which has meant that yahoo.com addresses have been considered spam. Mailman has released a workaround in version 2.1.18: https://www.mail-archive.com/mailman-users@python.org/msg64098.html The boost mailing list is currently on mailman 2.1.15. I'd strongly suggest that this should be updated as a matter of urgency else we'll find a lot of the conversations on this list will end up in the spam folder... Regards, James

1 0

Link problem
by Adolfo 19 May '16

19 May '16

Hi everyone, I am quite newbie on this and perhaps this is quite simple, sorry for the trouble. I am using VSC++ 2012, I have the boost version boost_1_60_0 and I have built it following the description in http://www.boost.org/doc/libs/1_60_0/more/getting_started/windows.html. No problem with batch files (bootstrap and b2). When I try to test the example code from section 6, I have the following linking error: Error 1 error LNK1104: no se puede abrir el archivo 'libboost_regex-vc110-mt-gd-1_60.lib' I have realised that in my ...\boost_1_60_0\stage\lib directory, all the .lib files have names like libboost_*-vc140-*-1_60.lib. Can anybody be so kind of telling me what I did wrong or where I have to change this?? Best wishes, Adolfo.

3 2

Re: [boost] [Boost-users] Boost 1.61.0 has been released
by Tom Kent 18 May '16

18 May '16

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 > On Wed, May 18, 2016 at 2:05 AM, Vladimir Prus <vladimir.prus(a)gmail.com> wrote: > > On 17/05/2016 13:16, Vladimir Prus wrote: > > > On 13/05/2016 15:07, Rene Rivera wrote: > > > Release 1.61.0 of the Boost C++ Libraries is now available. > > > > > > For details, including download links, see http://www.boost.org/users/news/version_1.61.0 > > > > > > You can also download directly from SourceForge: http://sourceforge.net/projects/boost/files/boost/1.61.0/ > > > > You can optionally verify integrity of the source downloads using the attached signed checksums file. > > Tom has pointed a typo in file names in the file. Correct one is now attached, and instructions > for validating are the same: I now get good hashes and a good signature verification. I'm signing this email with my private key "Thomas Kent <teeks99(a)yahoo.com>" for the record. Tom Original Attachment: - -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 a547bd06c2fd9a71ba1d169d9cf0339da7ebf4753849a8f7d6fdb8feee99b640 boost_1_61_0.tar.bz2 a77c7cc660ec02704c6884fbb20c552d52d60a18f26573c9cee0788bf00ed7e6 boost_1_61_0.tar.gz fa1c34862b7ba8674ed6e064a14667a11830c6252f702d9458451834b74f7815 boost_1_61_0.7z 02d420e6908016d4ac74dfc712eec7d9616a7fc0da78b0a1b5b937536b2e01e8 boost_1_61_0.zip - -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBCAAGBQJXPBG3AAoJEA8aPs1OrCMWL1QQAJCsQbr4rxpQMDssW5O0Fupg aw8Us0CnfPLSPW5gMdQoIQxu/n1SNobn4Vg1/hyTfweufqFwHFRxJnHiWtlbI/GB q1TueLPCxcJUi6lT7ZOVcpKb6AS6vOnSJRODQ0zk62phKBmLDUxiBI46FlCkzHbz uWVG+wttzk2Skeb3400xWEMtM0fgX3oJenh5Ye//oD7biJC0aIVPrnkauQ2Nze0l 2nG8e7w7ZzlXEx0Ei8KHiyBsFMj0/O5JIJKbxWorBAeELSgWun0YqB9EnrbADGDp XCEUUg1FB2llTmpG3a/dyv8fMlAS/ENka7e4aGuIHAlyfmTKGx+9Zd813XLiSjvw CHCyp+b7v0dGn2RFrVhgl9qRyFKgcvYjhhsA42iO0eFt7rgkoXV72qQzjSClzjkS jJrcj8dxJkZVMJ9tWKCmzGoPYRj4z8Nt8dw7HDqFGb7/2Rw6FZ18N9SsqHD+y9G3 TZhPPYQJVqckM9qo0CFzYwZpjiBgLhhQI6iEUh8UB8xXB09cJfgHGvyszXsvR+3l xQvKq19BYWHlPoi4Ie+YUzxF81Pgj98mbnwXLcgUoLBZWueXGfFdf+nBvyDoQyli LbHEpt0cGwWyfk+HXt+Qa5dmSRMr7zZpmWseBr9/6J1gCoNxAEOqHZ1hCrpFIHWt pM+LHXktogy3CpBV2IXH =6T/2 - -----END PGP SIGNATURE----- -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJXPIMxAAoJEO5CwwL7YZSoqjQQAME+iTB9MhE3Jz2AAl7+tohB +v8U25f1C2X6qbVTKCynG+FzdfthIOwdLeReIcY8fUD7O30LqhYpfjPgDJvRqvDT pjU/jxD4ORLn9aEtNGcEX+EtSuO9dV2eZP3cDcyNnTRUu26O6LkJN2wRb2BFa1kN coVuhNSD7I8BBpiNgWo/J09Ajv3GRags8y6WHjC6IUD5isGUGMGD7udhjD6qcX/q hiyTfdzkqMo5lDmGj20JCsuXg1Iqku5JKydeDH4vunpZokbDmtSja992kzMSRFGK CemHapPcml5ei8ubvEnROYLPcIpcrL9zpO6vTpKRQs5dzfJDkeiCeS9Zgvm/fb7h G4yoUD08ccU0HHwRVCNdpHXPRgSSh3JJp94XuWO/sFgNg0q+5pGeGoqnveBaroqu zAgdcteBmw+YoU39bWt+kPu5zVbVygHZNXpC0BOKc8+IP86wwOvEHDEUm1o5UQma QPWQrZuoMcGNE9SZn1K1Zg+oJ6KG5Ykp5SOhhb3SrV7Oqb3SN3lg9lbEyGBHa/lY SUSLdMlkcEtUITRu6KcYJAVw9Pbq2O8AZWYPZSjToZxpEFv4+53VOSr3mkpFQxMc dzral/n0Yyw+XsqIke1kdzWpbCGrPAy0Pm5BGB7Fsi9iq1JbVjVi47ZIk4L16L0H gmgII1jsJy8+R3XXpGRZ =x/tu -----END PGP SIGNATURE-----

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Re: [boost] [Boost-users] Boost 1.61.0 has been released
by Daniel James 18 May '16

18 May '16

On 17 May 2016 at 21:42, Raffi Enficiaud <raffi.enficiaud(a)mines-paris.org> wrote: > > Thanks! > The boost.test documentation has the banner "click here to view the latest > version on this page" on the top: > http://www.boost.org/doc/libs/1_61_0/libs/test/doc/html/index.html > > Sorry for the late mention, I thought it was because 1.61 was not released > yet. > Anything I did wrong? Anything I can do? Sorry about that, it was a bug. It should be fixed now, you might have to shift-refresh to see the fixed page.

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Review Wizard Report for May 2016
by Ronald Garcia 18 May '16

18 May '16

============================================== Review Wizard Status Report for May 2016 ============================================== News ==== 1. Boost 1.58 Released April 2015. New Libraries: Endian, Sort 2. Metaparse Library Accepted 3. Hana Library Accepted 4. DLL Library Accepted 5. Http Library Rejected 6. Boost 1.59 Released August 2015. New Libraries: Coroutine2, Convert 7. AFIO Library Reviewed 8. Fiber Library Conditionally Accepted 9. Boost 1.60 Released December 2015. New Libraries: Variadic Macro Data 10. Quaternions, Vectors, Matrices Accepted 11. Fit Library Rejected 11. Boost 1.61 Released May 2016. New Libraries: Compute, DLL, Metaparse, Hana Open Issues =========== The following libraries have review managers, but have not yet been scheduled for review: * Range Extensions - added May 2012; review manager: Neil Groves. The following libraries have been reviewed and await reports from their review managers: * AFIO - reviewed August 2015; review manager: Ahmed Charles. The following libraries have been accepted to Boost, but have not yet been integrated into Boost Git: * Contract - accepted September 2012; author: Lorenzo Caminiti. * Quaternions,Vectors,Matrices - accepted December 2015; author: Emil Dotchevski The following libraries have been accepted and submitted to Boost Git, but have not yet appeared in a release: * none The following libraries have been accepted provisionally to Boost, but have not been submitted for mini-review and full acceptance: * none General Announcements ===================== As always, we need experienced review managers. Please take a look at the list of libraries in need of managers and check out their descriptions. In general review managers are active boost participants, including library contributors, infrastructure contributors, and other mailing list participants with a substantial track record of constructive participation. If you can serve as review manager for any of them, email Ron Garcia or John Phillips, "rxg at cs dot ubc dot ca" and "johnphillipsithica at gmail dot com" respectively. We are also suffering from a lack of reviewers. While we all understand time pressures and the need to complete paying work, the strength of Boost is based on the detailed and informed reviews submitted by you. If you are interested in reviewing a library but won't have time during the review period, you can always prepare your review ahead of time. No rule says you can only work on a review during the review period. A link to this report will be posted to www.boost.org. If you would like us to make any modifications or additions to this report, please email Ron or John. The review schedule is an unordered list of the libraries awaiting review. As such, any library on the schedule can be reviewed once the developer is ready, a review manager has been secured, and the manager, developer, and wizards agree on a date to schedule the review. Review Schedule =============== * Join (M) * Block Pointer (M) * Singularity (M) * Extended Complex Numbers (M) * Boost.Range Extensions * Nowide (M) * Array (M) * STL Extensions (M) * Countertree (M) * Process (M) * Application (M) * Edit Distance (M) * Mixin (M) * Dependency Injection (M) * Segmented Tree * Fiber ``(M)`` marks libraries that need review managers. -------------------- Join ---- :Author: Yigong Liu :Review Manager: Needed :Download: http://channel.sourceforge.net/ :Description: Join is an asynchronous, message based C++ concurrency library based on join calculus. It is applicable both to multi-threaded applications and to the orchestration of asynchronous, event-based applications. It follows Comega's design and implementation and builds with Boost facilities. It provides a high level concurrency API with asynchronous methods, synchronous methods, and chords which are "join-patterns" defining the synchronization, asynchrony, and concurrency. Block Pointer ------------- :Author: Phil Bouchard :Review Manager: Needed :Download: https://svn.boost.org/svn/boost/sandbox/block_ptr/ :Description: Deterministic memory manager of constant complexity capable of handling cyclic collections. Singularity ----------- :Author: Ben Robinson :Review Manager: Needed :Download: https://github.com/cppmaven/Singularity :Description: The Singularity Design Pattern allows you to restrict any class to a single instance. Unlike the infamous Singleton, Singularity gives you direct control over the lifetime of the object, does not require you to grant global access to the object, nor does it limit you to the default constructor for that object. Extended Complex Numbers ------------------------ :Author: Matthieu Schaller :Review Manager: Needed :Download: http://code.google.com/p/cpp-imaginary-numbers/ :Description: The library is an extension of the std::complex class addressing two issues: 1. The standard does not guaranty the behaviour of the complex class if instantiated with types other than float/double/long double. 2. Some calculation where pure imaginary numbers (i.e. multiples of sqrt(-1)) appear are unnecessarily slowed down due to the lack of support for these numbers. The code I submit contains two interleaved classes boost::complex and boost::imaginary which can be instantiated with any type T provided T overloads the usual arithmetic operators and some basic (real) mathematical functions depending on which complex function will be used. It is thus an extended version of Thorsten Ottosen's n1869 proposal (http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2005/n1869.html) Range Extensions ---------------- :Author: Akira Takahashi :Review Manager: Neil Groves :Download: https://github.com/faithandbrave/OvenToBoost :Description: This project adds some features of the Oven Range Library to Boost.Range. Features: - Additional Range Adaptors (taken, taken_while, dropped, dropped_while, elements, elements_key, memoized, outdirected) - Extensions for using Lambda (regular function, regular operator) - Infinite Range (iteration function) - and additional range utilities. Nowide ------ :Author: Artyom Beilis :Review Manager: Needed :Download: http://cppcms.com/files/nowide/ :Description: This library makes cross platform Unicode aware programming easier. It provides an implementation of standard C and C++ library functions, such that their inputs are UTF-8 aware on Windows without requiring to use Wide API. Array ----- :Author: Brian Smith :Review Manager: Needed :Download: https://github.com/BrianJSmith/Array :Description: The array class is a C++11 compatible implementation of static multidimensional arrays. STL Extensions -------------- :Author: Vadim Stadnik :Review Manager: Needed :Download: https://github.com/vstadnik/stl_ext_adv_review :Description: The proposed library [stl_ext_adv] offers augmented array based B+ trees and STL containers that support the interfaces of the C++03 sequences and associative containers. The library offers a number of extensions and performance improvements that are not available in C++03 and C++11 standard containers. Countertree ----------- :Author: Francisco Jose Tapia :Review Manager: Needed :Download: https://dl.dropbox.com/u/8437476/works/countertree_code_doc.zip :Description: This library is an implementation of a binary red-black counter tree. This tree have an additional counter in each leaf. This permit the access to the elements by the position, like in a vector. It is a random access container with random access iterators. COUNTERTREE This kind of trees have an additional counter in each leaf. This permit the access to the elements by the position, like in a vector. It is a random access container with random access iterators. With unordered information we have a vector with the same speed inserting and deleting in any position (O(log N)). With ordered information, we have the classes set, multiset, map and multimap, with identical interface than the STL classes, with the plus of access to the elements by position, like in a vector. The iterators are random access , and you can subtract them. SUBALLOCATOR The suballocator is a layer between the allocator and the data structures, compatible with any allocator with the STL definition. The suballocator replace to the allocator in the allocation of equal size elements. It provides speed, return the unused memory and decrease the memory used by the program and improve the cache performance due to the data locality improvement ( 30% of improvement of speed respect the std::allocator with GCC 4.7) Process ------- :Author: Boris Schaeling :Review Manager: Needed :Download: http://www.highscore.de/boost/process0.5/process.zip :Description: Boost.Process is a library to manage system processes. It can be used to: * create child processes * setup streams for child processes * communicate with child processes through streams (synchronously or asynchronously) * wait for processes to exit (synchronously or asynchronously) * terminate processes Application ----------- :Author: Renato Tegon Forti :Review Manager: Needed :Download: https://github.com/retf/Boost.Application :Documentation: http://www.dokfile.com/appbeta4/docs/libs/application/doc/html/index.html :Description: Application provides an application environment, or start point to any people that want a basic infrastructure to build an system application on Windows or Unix Variants (e.g. Linux, MacOS). Application uses behaviours modeled using 'aspects' concept proposed by 'Vicente J. Botet Escriba', that allow easy extension and customization of library components. The application modes uses these components internally to achieve the user desirable behaviours. Application provide many useful ready-to-use features, e.g: * Run application as Windows Service; * Run application as UNIX/POSIX Daemon; * Plugin extension system; * Process(executable) Single instance Instantiation support; * Application SIGNAL/Callbacks customization; * Windows Service Setup feature; * And many others. Edit Distance ------------- :Author: Erik Erlandson :Review Manager: Needed :Download: https://github.com/erikerlandson/algorithm/tree/edit_distance/sequence :Description: The edit distance is the length of the shortest (or least-cost) edit script from one sequence to another, where an edit script is defined as a sequence of insertion, deletion and (optionally) substitution operations. The function implementing the edit distance is named edit_distance. This function will return the edit distance between two sequences, where sequences may be any valid range object supporting forward iteration. The edit_distance function will also, if requested, return the edit script. Mixin ----- :Author: Borislav Stanimirov :Download: https://github.com/iboB/boost.mixin :Documentation: http://ibob.github.io/boost.mixin/ :Review Manager: Needed :Description: Boost.Mixin is a library that allows the composition and modifications of polymorphic types at run time. Types and objects are constructed out of building blocks called mixins. The library uses the type boost::mixin::object as a placeholder, whose instances can be extended with existing classes (mixins), thus providing a particular instance with the functionality of all those types. Accessing the newly formed type's interface is made through messages: stand-alone functions generated by the library, which can be thought of as methods. This is given while also having full abstraction between the interface and the definition of types. An existing feature in another language similar to Boost.Mixin and also an inspiration for the library are the mixins in Ruby. The library also has similarities with the pattern entity-component-system. Dependency Injection -------------------- :Author: :Download: https://github.com/krzysztof-jusiak/di :Documentation: http://krzysztof-jusiak.github.io/di/boost/libs/di/doc/html :Incubator: http://rrsd.com/blincubator.com/bi_library/di-dependency-injection/?gform_p… :Review Manager: Needed :Description: Boost.DI is a dependency injection library improving manual dependency injection by simplifying object instantiation with automatic dependencies injection. Using Boost.DI has many advantages over manual dependency injection. * Reduce boilerplate code (No factories, no objects creation in specific order) * Reduce cost of maintenance effort (Constructor signature change won't affect di configuration) * Reduce testing effort * Give better control of what and how is created (Policies, Providers) * Give better understanding about objects hierarchy (UML Dumper) Segmented Tree -------------- :Author: Chris Clearwater :Download: http://rrsd.com/blincubator.com/bi_library/segmentedtreeseq-2/?gform_post_i… :Repository: http://github.com/det/segmented_tree :Documentation: https://det.github.io/segmented_tree :Review Manager: Glen Fernandes :Description: SegmentedTreeSeq is a sequence data structure like vector and deque that supports efficient random access insert and erase. It is implemented using B+Trees and has an emphasis on speed and a low memory overhead. Fiber ----- :Author: Oliver Kowalke :Download: https://github.com/olk/boost-fiber :Documentation: http://olk.github.io/libs/fiber/doc/html/ :Review Manager: Nat Goodspeed :Description: Boost.Fit is a header-only C++11/C++14 library that provides utilities for functions and function objects. Libraries under development =========================== See The Boost Library Incubator Project at http://blincubator.com for discussion of libraries currently under development.

2 1

Re: [boost] [proto][variant] variant crashes proto expression
by Igor R. 17 May '16

17 May '16

> // The values bound to the placeholders > Value *d[2]; <...> > // The result of evaluating arithmetic expressions > typedef Value& result_type; So, you store pointers to the variants and return references, thus preventing copying. But why does the copying cause the aforementioned crash? Does it look like a bug in Proto? That's quite weird, because I never encountered any issue with variant copying... -- View this message in context: http://boost.2283326.n4.nabble.com/proto-variant-variant-crashes-proto-expr… Sent from the Boost - Dev mailing list archive at Nabble.com.

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Boost Build and Test
by Robert Ramey 17 May '16

17 May '16

I started a new thread to accommodate the widening discussion on CMake. Build and Test systems: I've always been a big complainer about Boost Build. Now I'm a big complainer about CMake as well. Just so you know. I always found it weird that the buiding of libraries jam file was stashed in it's own directory - build while jam files for other components like test and building docs was found inside their respective directories. I also added to the serialization library some other jam files in subdirectories example and in performance. So to me by far the most natural place to find the library jam file would be in the directory we've agreed to name src. I never made any issue of this as my whole progress through life is about moving on to get my own projects done. Largely motivated by the desire to do cutting edge C++ development I replaced my old windows system with a mac mini. Soon I wanted to build and test my projects in XCode IDE. I like to use an IDE, but setting it and maintaining it for a project like the serialization library is an incredible amount of work. So I resolved to setup CMake to do the job. I had exposure to CMake before and found it no better than all the other build systems. But it needed to do what I wanted it to do - create the IDE project and it was very popular. So I managed to make it work in this context and the result has been quite satisfactory. But making it run all the tests I want to run - different compilers, libraries, etc. etc. integrating with my own library_status dashboard builder looked like a serious pain and I already had an elaborate Jamfile set for doing all of that. So upshot is I use them both for different purposes. I don't see anything wrong with that. In order not to upset the established structure I put my CMakeLists.txt file inside it's own directory. If it was totally up to me, what I'd like to see is: a) jam files in the build directory moved to src b) thereby acknowledging the practice of having jam files in the same directories which contain the build sources. c) which is pretty much the same as the CMake approach. c) official tolerance for including other build systems at the same level such as CMakeLists.txt and maybe MS projects and solutions. d) official tolerence for including a top level CMakeLists.txt. Personally I don't think this is necessary or even a good idea - but I want to leave that as a separate discussion. Robert Ramey

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Final benchmark graphs for Colony vs std:: containers now available
by Soul Studios 17 May '16

17 May '16

Re-wrote my benchmark code from scratch a month or two ago with some help from Baptiste Wiche, have run over std::list, std::map, std::multiset, std::deque, std::vector, and for GCC, Chris's segmented_tree implementation. To be honest there's not much point comparing against segmented_tree, as the goals are totally different (efficient random access insertion for segtree, vs efficient unordered erasure/insertion/iteration without pointer invalidation colony), but there was some interest last time I wrote here. In addition I compared against other methods for ensuring pointer/index validity using deques and vectors, to see how those things pan out. Graphs are available here: http://www.plflib.org/colony.htm#benchmarks and here: http://www.plflib.org/stack.htm There are also MSVC 2013 results linked to in the first paragraph of the benchmarks. Comments are welcome, but please read the page first. Stack performs particularly well, outperforming all alternatives in both GCC/MSVC.

3 16

Boost ICL tests attempting to pass non-bidirectional iterator to std::reverse_copy
by Billy O'Neal (VC LIBS) 16 May '16

16 May '16

Hi folks. I'm not a Boost.ICL expert, but we detected this one failure with our in-development STL and this test case: template <ICL_IntervalSet_TEMPLATE(_T) IntervalSet, class T> void interval_set_element_iter_4_discrete_types() { typedef IntervalSet<T> IntervalSetT; typedef typename IntervalSetT::interval_type IntervalT; typedef std::vector<T> VectorT; IntervalSetT set_a; set_a.add(I_I(1,3)).add(I_I(6,7)); VectorT vec(5), cev(5); vec[0]=MK_v(1);vec[1]=MK_v(2);vec[2]=MK_v(3);vec[3]=MK_v(6);vec[4]=MK_v(7); cev[0]=MK_v(7);cev[1]=MK_v(6);cev[2]=MK_v(3);cev[3]=MK_v(2);cev[4]=MK_v(1); VectorT dest; std::copy(elements_begin(set_a), elements_end(set_a), std::back_inserter(dest)); BOOST_CHECK_EQUAL( vec == dest, true ); dest.clear(); std::copy(elements_rbegin(set_a), elements_rend(set_a), std::back_inserter(dest)); BOOST_CHECK_EQUAL( cev == dest, true ); dest.clear(); std::reverse_copy(elements_begin(set_a), elements_end(set_a), std::back_inserter(dest)); BOOST_CHECK_EQUAL( cev == dest, true ); dest.clear(); std::reverse_copy(elements_rbegin(set_a), elements_rend(set_a), std::back_inserter(dest)); BOOST_CHECK_EQUAL( vec == dest, true ); } which produces this failure: C:\Dev\WCFB01_01\binaries\x86ret\inc\algorithm(1672): error C2665: 'std::_Reverse_copy1': none of the 2 overloads could convert all the argument types C:\Dev\WCFB01_01\binaries\x86ret\inc\algorithm(1655): note: could be '_OutIt std::_Reverse_copy1<_Iter,_OutIt>(_BidIt,_BidIt,_OutIt,std::random_access_iterator_tag,std::random_access_iterator_tag)' with [ _OutIt=std::back_insert_iterator<VectorT>, _Iter=boost::icl::element_iterator<std::_Tree_const_iterator<std::_Tree_val<std::_Tree_simple_types<boost::icl::discrete_interval<bicremental_type_5,std::less>>>>>, _BidIt=boost::icl::element_iterator<std::_Tree_const_iterator<std::_Tree_val<std::_Tree_simple_types<boost::icl::discrete_interval<bicremental_type_5,std::less>>>>> ] C:\Dev\WCFB01_01\binaries\x86ret\inc\algorithm(1645): note: or '_OutIt std::_Reverse_copy1<_Iter,_OutIt>(_BidIt,_BidIt,_OutIt,std::bidirectional_iterator_tag,std::_Any_tag)' with [ _OutIt=std::back_insert_iterator<VectorT>, _Iter=boost::icl::element_iterator<std::_Tree_const_iterator<std::_Tree_val<std::_Tree_simple_types<boost::icl::discrete_interval<bicremental_type_5,std::less>>>>>, _BidIt=boost::icl::element_iterator<std::_Tree_const_iterator<std::_Tree_val<std::_Tree_simple_types<boost::icl::discrete_interval<bicremental_type_5,std::less>>>>> ] C:\Dev\WCFB01_01\binaries\x86ret\inc\algorithm(1672): note: while trying to match the argument list '(boost::icl::element_iterator<std::_Tree_const_iterator<std::_Tree_val<std::_Tree_simple_types<boost::icl::discrete_interval<DomainT,Compare>>>>>, boost::icl::element_iterator<std::_Tree_const_iterator<std::_Tree_val<std::_Tree_simple_types<boost::icl::discrete_interval<DomainT,Compare>>>>>, std::back_insert_iterator<VectorT>, boost::iterators::detail::iterator_category_with_traversal<std::input_iterator_tag,Traversal>, std::output_iterator_tag)' with [ DomainT=bicremental_type_5, Compare=std::less ] and [ DomainT=bicremental_type_5, Compare=std::less ] and [ Traversal=boost::iterators::bidirectional_traversal_tag ] c:\dev\wcfb01_01\src\qa\vc\fe\3rdpartycomp\boost_1_60_0\libs\icl\test\fastest_interval_set_\../test_interval_set_shared.hpp(810): note: see reference to function template instantiation '_OutIt std::reverse_copy<boost::icl::element_iterator<std::_Tree_const_iterator<std::_Tree_val<std::_Tree_simple_types<boost::icl::discrete_interval<DomainT,Compare>>>>>,std::back_insert_iterator<VectorT>>(_BidIt,_BidIt,_OutIt)' being compiled with [ _OutIt=std::back_insert_iterator<VectorT>, DomainT=bicremental_type_5, Compare=std::less, _BidIt=boost::icl::element_iterator<std::_Tree_const_iterator<std::_Tree_val<std::_Tree_simple_types<boost::icl::discrete_interval<bicremental_type_5,std::less>>>>> ] c:\dev\wcfb01_01\src\qa\vc\fe\3rdpartycomp\boost_1_60_0\libs\icl\test\fastest_interval_set_\../fastest_interval_set_cases.hpp(61): note: see reference to function template instantiation 'void interval_set_element_iter_4_discrete_types<boost::icl::interval_set,discrete_type_2>(void)' being compiled We are considering reverting this enforcement of iterator category tag in our STL, but technically a standard library appears within its rights to reject this. Billy Robert O'Neal III SDE II - Visual C++ Libraries bion(a)microsoft.com

1 0

media file errors
by Rainer Deyke 15 May '16

15 May '16

"CDs/Reverend Bizarre - III - So Long Suckers (disc 1)" is redundant and should be deleted. In "CDs/Shadow Gallery - Room V": "Shadow Gallery - Seven Seas.mp3" -> "Shadow Gallery - Seven Years.mp3" -- Rainer Deyke (rainerd(a)eldwood.com)

1 0

Call for Submissions: International Conference on Information Society (i-Society 2016), Technical Co-Sponsored by IEEE UK/RI Chapter!
by Faye Bewsy 13 May '16

13 May '16

1 0

[proto][variant] variant crashes proto expression
by Igor R 13 May '16

13 May '16

The following code is a slightly modified Proto calc2 example. Instead of doubles I use variant<int, double>, and the expression is just _1 = _2. This code triggers assertion in variant/detail/forced_return.hpp, so it looks like some variant instance gets messed up. It happens when the value returned from proto::eval(*this, ctx) is being copied. It can be reproduced both with MSVC and gcc, with Boost 1.60. Is there any workaround for this issue? Thanks. ////////////// #include <iostream> #include <boost/proto/proto_typeof.hpp> #include <boost/proto/core.hpp> #include <boost/proto/context.hpp> #include <boost/variant.hpp> namespace proto = boost::proto; using proto::_; typedef boost::variant<int, double> var_t; template<typename Expr> struct calculator_expression; // Tell proto how to generate expressions in the calculator_domain struct calculator_domain : proto::domain<proto::generator<calculator_expression> > {}; // Will be used to define the placeholders _1 and _2 template<int I> struct placeholder {}; // Define a calculator context, for evaluating arithmetic expressions // (This is as before, in calc1.cpp) struct calculator_context : proto::callable_context< calculator_context const > { // The values bound to the placeholders var_t d[2]; // The result of evaluating arithmetic expressions typedef var_t result_type; explicit calculator_context(const var_t &d1 = var_t(), const var_t &d2 = var_t()) { d[0] = d1; d[1] = d2; } // Handle the evaluation of the placeholder terminals template<int I> result_type operator ()(proto::tag::terminal, placeholder) const { return d[ I - 1 ]; } }; // Wrap all calculator expressions in this type, which defines // operator () to evaluate the expression. template<typename Expr> struct calculator_expression : proto::extends<Expr, calculator_expression<Expr>, calculator_domain> { explicit calculator_expression(Expr const &expr = Expr()) : calculator_expression::proto_extends(expr) {} BOOST_PROTO_EXTENDS_USING_ASSIGN(calculator_expression<Expr>) // Override operator () to evaluate the expression var_t operator ()() const { calculator_context const ctx; return proto::eval(*this, ctx); } var_t operator ()(const var_t &d1) const { calculator_context const ctx(d1); return proto::eval(*this, ctx); } var_t operator ()(const var_t &d1, const var_t &d2) const { calculator_context const ctx(d1, d2); return proto::eval(*this, ctx); } }; // Define some placeholders (notice they're wrapped in calculator_expression<>) calculator_expression<proto::terminal< placeholder< 1 > >::type> const _1; calculator_expression<proto::terminal< placeholder< 2 > >::type> const _2; // Now, our arithmetic expressions are immediately executable function objects: int main() { BOOST_PROTO_AUTO(expr, _1 = _2); var_t a1(1), a2(2.5); expr(a1, a2); return 0; }

3 2

[intrusive] crash with slist push_back
by Arpan Sen 12 May '16

12 May '16

Hi Boost Dev, Please consider the following code, this crashes with slist but works just fine if I replace slist with list. Also flat_map crashes but std::map works fine. Am I doing something gross or is there a bug here? #include <iostream> #include <boost/container/flat_map.hpp> #include <map> //#include <boost/intrusive/list.hpp> #include <boost/intrusive/slist.hpp> using namespace boost::intrusive; struct m : public slist_base_hook<> { int n; public: m(int k) : n(k) { } }; int main() { boost::container::flat_map<int, slist<m, cache_last<true> > > c1; std::map<int, slist<m, cache_last<true> > > c2; m* m1 = new m(22); c1[1].push_back(*m1); m* tt = new m(99); c2[1].push_back(*tt); } Regards Arpan

2 1

Using thread_local with Boost.Thread
by Ruediger Berlich 11 May '16

11 May '16

Hi there, I am curious whether it would be possible to use C++11 thread_local instead of Boost's own TLS, while continuing to use Boost.Thread ? I assume that there will be problems if Boost falls back to native pthread ? Kind Regards, Beet

1 0

Boost 1.61.0 Release Candidate 2
by Vladimir Prus 11 May '16

11 May '16

The second release candidates for the 1.61.0 release are now available at: http://boost.cowic.de/rc/boost_1_61_0_rc2.zip http://boost.cowic.de/rc/boost_1_61_0_rc2.7z http://boost.cowic.de/rc/boost_1_61_0_rc2.tar.bz2 http://boost.cowic.de/rc/boost_1_61_0_rc2.tar.gz The SHA256 checksums are as follows: fa1c34862b7ba8674ed6e064a14667a11830c6252f702d9458451834b74f7815 boost_1_61_0_rc2.7z a547bd06c2fd9a71ba1d169d9cf0339da7ebf4753849a8f7d6fdb8feee99b640 boost_1_61_0_rc2.tar.bz2 a77c7cc660ec02704c6884fbb20c552d52d60a18f26573c9cee0788bf00ed7e6 boost_1_61_0_rc2.tar.gz 02d420e6908016d4ac74dfc712eec7d9616a7fc0da78b0a1b5b937536b2e01e8 boost_1_61_0_rc2.zip The changes relative to RC1 are MSVC fixes for signals2 and graph libraries. 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. The signed list of checksums is also attached, signed with the following key: https://pgp.mit.edu/pks/lookup?op=get&search=0xDA472E8659753BA4 Key fingerprint C5F0 F367 AA66 616F B839 806E DA47 2E86 5975 3BA4 Thanks! -- The release managers

9 14

[lockfree] _ENABLE_ATOMIC_ALIGNMENT_FIX for VS 2015 Update 2
by Stephan T. Lavavej 11 May '16

11 May '16

Hi, While running Boost.Lockfree's tests, one of our compiler devs encountered the following failure: freelist_test.cpp c:\wcfb01\binaries\x86chk\inc\atomic(659): error C2338: You've instantiated std::atomic<T> with sizeof(T) equal to 2/4/8 and alignof(T) < sizeof(T). Before VS 2015 Update 2, this would have misbehaved at runtime. VS 2015 Update 2 was fixed to handle this correctly, but the fix inherently changes layout and breaks binary compatibility. Please define _ENABLE_ATOMIC_ALIGNMENT_FIX to acknowledge that you understand this, and that everything you're linking has been compiled with VS 2015 Update 2 (or later). c:\wcfb01\binaries\x86chk\inc\atomic(669): note: see reference to class template instantiation 'std::_Atomic_base<_Ty,4>' being compiled with [ _Ty=boost::lockfree::detail::tagged_index ] e:\boost\boost\boost\lockfree\detail\freelist.hpp(608): note: see reference to class template instantiation 'std::atomic<boost::lockfree::detail::tagged_index>' being compiled e:\boost\boost\boost\lockfree\detail\freelist.hpp(609): note: see reference to class template instantiation 'boost::lockfree::detail::fixed_size_freelist<T,NodeStorage>' being compiled call "C:\WCFB01\binaries\x86chk\bin\i386\vcvarsall.bat" x86 >nul cl /Zm800 -nologo @"..\bin.v2\libs\lockfree\test\freelist_test.test\msvc-latest\debug\threading-multi\freelist_test.obj.rsp" ...failed compile-c-c++ ..\bin.v2\libs\lockfree\test\freelist_test.test\msvc-latest\debug\threading-multi\freelist_test.obj... with the following type: class tagged_index { public: typedef boost::uint16_t tag_t; typedef boost::uint16_t index_t; protected: index_t index; tag_t tag; }; This is by design - your tagged_index has align 2, size 4, triggering the need for my atomic alignment fix. As the static_assert advises, your code needs to define _ENABLE_ATOMIC_ALIGNMENT_FIX in order to pass. If this has already been fixed in 1.61.0, then that's great (I haven't checked). Thanks, STL

5 14

Getting started with boost in Codeblocks
by Karan Kapoor 11 May '16

11 May '16

Hi, This is Karan Kapoor,a 3rd year UG student at NSIT. Can somebody guide me how to get started with boost libraries while i am using codeblocks. Karan Kapoor

2 1

Boost.Random subtract_with_carry doesn't like m == numeric_limits<result_type>::digits
by Billy O'Neal (VC LIBS) 10 May '16

10 May '16

Hello, Boost folks. I found a bug in subtract_with_carry_engine while fixing a bug in MSVC++'s implementation of the same, where m == numeric_limits<result_type>::digits. Consider the following: #include <stdlib.h> #include <stdio.h> #ifdef USE_BOOST #include <boost/random/subtract_with_carry.hpp> using namespace boost::random; #else #include <random> using namespace std; #endif template <typename Engine> typename Engine::result_type run_10k(Engine engine) { for (int i = 0; i < 9999; ++i) { engine(); } return engine(); } int main() { subtract_with_carry_engine<unsigned long long, 64, 10, 24> ull_swc; ull_swc.seed(0x12341234'00000000); printf("0x%016llX\n", run_10k(ull_swc)); } MSVC++ said: 0xFCF0A4776BA0A6A8 Libstdc++ says: 0x01316AEA3646F686 Libc++ says: 0x01316AEA3646F686 Boost 1.60.0/libc++ + Clang says: 0x69E18848FE1BD36D Boost 1.60.0/libstdc++ + g++ says: 0x1DD6C263C41EEED0 MSVC++'s bug was that we did the underflow check incorrectly resulting in the carry bit always being set if m == numeric_limits<result_type>::digits. I fixed that and MSVC++ will agree with libstdc++ and libc++ in the next update; but boost's behavior here is still strange. Hope that helps, Billy Robert O'Neal III SDE II - Visual C++ Libraries bion(a)microsoft.com

2 1

[thread] API for getting/setting thread name in Boost?
by Bob Summerwill 10 May '16

10 May '16

I've also been working with an external developer which is getting Ethereum C++ working on Alpine Linux, as a statically linked executable using musl, rather than glibc. One rather confusing element was related to setting and getting thread names, which is the process of working through this issue, I find appears not to have made its way into either Boost or the C++11 standard library, though it must be a very common cross-platform use-case. https://github.com/ethereum/libweb3core/pull/73 https://github.com/ethereum/libweb3core/pull/73/files I've just added this comment-block, while fixing the issue: /// Set the current thread's log name. /// /// It appears that there is not currently any cross-platform way of setting /// thread names either in Boost or in the C++11 runtime libraries. What is /// more, the API for 'pthread_setname_np' is not even consistent across /// platforms which implement it. /// /// A proposal to add such functionality on the Boost mailing list, which /// I assume never happened, but which I should follow-up and ask about. /// http://boost.2283326.n4.nabble.com/Adding-an-option-to-set-the-name-of-a-bo… /// /// man page for 'pthread_setname_np', including this crucial snippet of /// information ... "These functions are nonstandard GNU extensions." /// http://man7.org/linux/man-pages/man3/pthread_setname_np.3.html /// /// Stack Overflow "Can I set the name of a thread in pthreads / linux?" /// which includes useful information on the minor API differences between /// Linux, BSD and OS X. /// http://stackoverflow.com/questions/2369738/can-i-set-the-name-of-a-thread-i… /// /// musl mailng list posting "pthread set name on MIPs" which includes the /// information that musl doesn't currently implement 'pthread_setname_np' /// https://marc.info/?l=musl&m=146171729013062&w=1 void setThreadName(std::string const& _n); Would I be right in assuming that this never happened? http://boost.2283326.n4.nabble.com/Adding-an-option-to-set-the-name-of-a-bo… If not, where can I log an issue to request that we revisit that? From what I can see, everybody is likely just cut-and-pasting much the same code for this functionality. http://stackoverflow.com/questions/10121560/stdthread-naming-your-thread Cheers, Bob Summerwill -- bob(a)summerwill.net

2 7

[config] Boost and the Intel (Linux) compiler
by Bob Summerwill 10 May '16

10 May '16

I am a developer on the Ethereum C++ client ( https://github.com/ethereum/webthree-umbrella) and have been working with an external developer on adding support to the codebase for building with the Intel Compiler on Ubuntu. Here is the full log of pain :-) https://github.com/ethereum/webthree-umbrella/issues/396 We've already merged various changes, and we appear to be getting down to the real hard ones, which are now mainly clustered around build issues with boost::multiprecision and seeming limitations with the Intel compiler and Like so: /home/libweb3core/libdevcore/Base64.h(48): error: no suitable conversion function from "boost::multiprecision::number<boost::multiprecision::backends::cpp_int_backend<160U, 160U, boost::multiprecision::unsigned_magnitude, boost::multiprecision::unchecked, void>, boost::multiprecision::et_off>" to "unsigned int" exists unsigned r = (unsigned)(a - a / 36 * 36); // boost's % is broken ^ detected during instantiation of "std::string dev::toBase36(const dev::FixedHash<N> &) [with N=20UL]" at line 114 of "/home/libethereum/libethcore/ICAP.cpp" This appears to be the key observation: https://github.com/ethereum/webthree-umbrella/issues/396#issuecomment-20659… "In summary, the intel platform supports this "convert_to" member function, but does not support implicit conversion of boost multiprecision types" Has anybody worked with Boost and the Intel compiler who might have some further insight into whether there is some way in which the Intel compiler "warts" can be handed within Boost? Or are we stuck with these nasty diffs/workarounds? https://github.com/ethereum/libethereum/pull/224/files https://github.com/ethereum/libweb3core/pull/68/files Cheers, Bob Summerwill Developer, Ethereum Foundation -- bob(a)summerwill.net

3 4

github issues tracking listing
by Vicente J. Botet Escriba 09 May '16

09 May '16

Hi, I would like to have the possibility to have github issues in my boost modules (thread/chrono/ratio). I see that Boost.Hana has its own issue list. What I need to do to add the possibility to add issues? Best, Vicente

3 3

Boost 1.61.0 Release Candidate 1
by Vladimir Prus 09 May '16

09 May '16

The release candidates for the 1.61.0 release are now available at: http://boost.cowic.de/rc/boost_1_61_0_rc1.zip http://boost.cowic.de/rc/boost_1_61_0_rc1.7z http://boost.cowic.de/rc/boost_1_61_0_rc1.tar.bz2 http://boost.cowic.de/rc/boost_1_61_0_rc1.tar.gz The SHA256 checksums are as follows: dcd11a91a412b2e8a78678b38cb2a74857e61f9bfe2577de9fd70be770100d54 boost_1_61_0_rc1.7z 476937369c7a82103b734ccae85d35a523cdb7f8462c5f2fe1217ff0c8e2a7df boost_1_61_0_rc1.tar.bz2 e60dee39ebb29d24bf8a4ef9aec34dbb8c1b9b219d4737ea4b358f38b1aab2b7 boost_1_61_0_rc1.tar.gz e5f662f44a65c5c19450b8a1c07f75c7d5f16e58667871e856ba3984ec082006 boost_1_61_0_rc1.zip 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. The signed list of checksums is also attached, signed with the following key: https://pgp.mit.edu/pks/lookup?op=get&search=0xDA472E8659753BA4 Key fingerprint C5F0 F367 AA66 616F B839 806E DA47 2E86 5975 3BA4 Thanks! -- The release managers

14 38

[Style] Import a C function with wrong signature on purpose
by Klemens Morgenstern 08 May '16

08 May '16

Hi, for the boost.process library I need WinAPI functions which take an enumerator. Problem is: the forward-declaration doesn't work here, even with C++11. I.e. this code is still illegal, because X has a non-fixed type: enum X {}; enum X : typename std::underlying_type<X>::type ; I do however know which values the enum has take, thus I can redeclare it and have the reasonable expectation, that it will use the same underlying type. So theoretically, I could import the function into a seperate namespace (using extern "C") and use it, while having it declared with another enum type. I.e. you have in some C code the declaration: enum X { a,b,c}; void f(X); And I'll write in my code without including the other header: namespace import_thingy { extern "C" { enum X { a,b,c}; void f(X); } To be absolutely sure, I'd add an test, which asserts that the underlying types are equal. Now of course, that would never be accepted into the boost/winapi module, but I could just add this in my library. Would this be a dealbreaker for a library attempting to become a boost-library? If so, I'd need to put it into a source file and include windows.h there, but I'd really like the library to be header-only and under no circumstances include windows.h there. Thanks, Klemens

2 6

What to do about std::binary_function and std::unary_function?
by Nick Matteo 07 May '16

07 May '16

std::binary_function and std::unary_function are deprecated, and scheduled to be removed from the standard in C++17. That means it's possible that code using these might soon fail to compile when targeting this standard. These are still used throughout Boost, including by the libraries Accumulators, Algorithm, Bimap, Function, Functional, GIL, Graph, ICL, MPI, Polygon, and Xpressive. You can see all the uses I found in the 1.61 beta boost/ directory at http://kundor.github.io/ubinary_function_list.html . All that these classes do are provide the typedefs result_type, and argument_type (for unary_function) or first_argument_type and second_argument_type (for binary_function). In particular, they do not include a virtual operator(), so that one cannot accept a function object polymorphically as a std::binary_function&, for example. So, although it is conceivable that C++98-era user code might check for inheritance from std::binary_function, it seems rather unlikely: practically all uses should just depend on the typedefs being present (which is what the standard library has always done). With modern C++ standards, the availability of std::result_of, decltype, and std::function make these typedefs redundant, and references to them are being phased out of the standard library (starting with deprecation.) It seems to me that there are four main possibilities for removing these classes from Boost. (I'll talk about binary_function in the following, but it all applies equally to unary_function.) 1) Add some sort of compatibility macro to Boost.Config, to enable classes to inherit from std::binary_function if it is available, or add the appropriate typedefs if it is not. I don't think this is necessary. 2) Remove the inheritance from std::binary_function, and add the typedefs. This seems to be the default approach: it is used by the C++11 standard itself, and has also already been done by some Boost libraries, e.g. in container/string.hpp and in intrusive/priority_compare.hpp. The drawback here is increased verbosity. Instead of writing template <class T> struct functor : std::binary_function<T, T, bool> {...}; We must write template <class T> struct functor { typedef T first_argument_type; typedef T second_argument_type; typedef bool result_type; ... }; 3) A modification of approach 2: instead of manually adding the typedefs everywhere, make a base class to provide the typedefs somewhere in Boost. Then replace inheritance from std::binary_function<Arg1, Arg2, Result> with inheritance from boost::binary_function<Arg1, Arg2, Result>. 4) Just remove inheritance from std::binary_function (and don't provide typedefs.) This is the bold approach. The typedefs are redundant now: I think the only use in the standard library is by the deprecated std::not1/std:not2 and the deprecated binders std::bind1st/std::bind2nd (which are to be removed in C++17). This is the direction that the standard library is starting to head, with all uses of the typedefs deprecated and probably eventually removed, and even the provision of the typedefs optional in C++17 standard library function objects. This has already been done at least by Boost Interprocess in detail/mpl.hpp. Probably the best options are either (2) or (4). Should there be a default policy on what authors should do? Nick Matteo

5 6

Regression testing Clang/LLVM with VC14.
by degski 07 May '16

07 May '16

I have started a new thread as the other one "Testing of clang emualting the VC++ preprocessor on Windows" has become rather long and interlaced with less relevant musings. Here I would like to concentrate on the subject in the title. Sergey suggested I'd run regression tests, in the "other thread". I was hesitant at first, mostly due to the luke warm reception. Thanks to Google's simple coding of their spam filter, I actually missed the post by Niall Douglas of 4th of April. When it was referenced later and after I dug it from the archives, I became encouraged by the fact that maybe I wasn't all wrong and somebody within the community was actually thinking along similar lines as me. Following this I'd decided to take on regression testing. I chose to first simply test boost-develop against VC14, just to see how it goes. Some good, some bad. Was easy to set up (git already included with VC14, all what I needed to do was install python, which I normally have, but I'm having a new laptop). The bad, space required 44GB (advertised as 5GB). Possibly .pdb files (debugger symbols) are filling up disk-space uselessly. Next bad, the process finished with the following lines: # Done writing "C:\boost_develop\results\degski.xml". # Compressing "C:\boost_develop\results\degski.xml"... # Done writing "C:\boost_develop\results\degski.zip". # Uploading log archive "C:\boost_develop\results\degski.zip" to develop # <lambda> failed with message "[Errno 10013] An attempt was made to access a socket in a way forbidden by its access permissions" # Retrying (5 more attempts). # Uploading log archive "C:\boost_develop\results\degski.zip" to develop # <lambda> failed with message "[Errno 10013] An attempt was made to access a socket in a way forbidden by its access permissions" # Retrying (4 more attempts). # Uploading log archive "C:\boost_develop\results\degski.zip" to develop # <lambda> failed with message "[Errno 10013] An attempt was made to access a socket in a way forbidden by its access permissions" # Retrying (3 more attempts). # Uploading log archive "C:\boost_develop\results\degski.zip" to develop # <lambda> failed with message "[Errno 10013] An attempt was made to access a socket in a way forbidden by its access permissions" # Retrying (2 more attempts). # Uploading log archive "C:\boost_develop\results\degski.zip" to develop # <lambda> failed with message "[Errno 10013] An attempt was made to access a socket in a way forbidden by its access permissions" # Retrying (1 more attempts). # Uploading log archive "C:\boost_develop\results\degski.zip" to develop # <lambda> failed with message "[Errno 10013] An attempt was made to access a socket in a way forbidden by its access permissions" # Giving up. Traceback (most recent call last): File "run.py", line 71, in <module> runner(root) File "C:\boost_develop\boost_regression_src\regression.py", line 287, in __init__ self.main() File "C:\boost_develop\boost_regression_src\regression.py", line 624, in main getattr(self,action_m)() File "C:\boost_develop\boost_regression_src\regression.py", line 591, in command_regression self.command_upload_logs() File "C:\boost_develop\boost_regression_src\regression.py", line 538, in command_upload_logs lambda: File "C:\boost_develop\boost_regression_src\regression.py", line 663, in retry return f() File "C:\boost_develop\boost_regression_src\regression.py", line 546, in <lambda> self.dart_server ) File "C:\boost_develop\boost_regression_src\collect_and_upload_logs.py", line 430, in upload_logs upload_to_ftp( tag, logs_archive, ftp_proxy, debug_level, ftp_url ) File "C:\boost_develop\boost_regression_src\collect_and_upload_logs.py", line 256, in upload_to_ftp ftp = ftplib.FTP( ftp_site ) File "C:\Python27\lib\ftplib.py", line 120, in __init__ self.connect(host) File "C:\Python27\lib\ftplib.py", line 135, in connect self.sock = socket.create_connection((self.host, self.port), self.timeout) File "C:\Python27\lib\socket.py", line 575, in create_connection raise err socket.error: [Errno 10013] An attempt was made to access a socket in a way forbidden by its access permissions I've re-checked this page <http://www.boost.org/development/running_regression_tests.html>again, there's no mention of "registering" or something similar. Some tests must have failed, got prompted for starting the debugger twice (is the latter normal). This was a test-run (testing the testing), with VC14U2. Assuming the above can get sorted, I would in reality like to test Clang/LLVM (with VC14U2). I would like to ask (Niall Douglas in particular, I guess) what the suggested parameters to run.py should be for this combo. Should I target clang.exe or clang-cl.exe, develop or master. What about Clang/C2? How to reduce disk-space usage? degski

5 7

proposed new library "histogram"
by Hans Dembinski 06 May '16

06 May '16

Hi everybody, I recently added a new library called "histogram" to the Boost Incubator. I would like to advertise it a little here in the hope to find a person interested in reviewing it. I hope that shameless self-advertisement is not going against some rule of this list, but I am sure you will let me know. My background is in analysis of big data in the fields of particle physics and astroparticle physics. Boost is very popular among my peers, since it is a free, high-quality, rich, and very well maintained collection of libraries. There is a growing number of tools to do statistical analysis in Boost and I think this project would fit in nicely, and fill a gap. We work with histograms a lot, so that's why my interest came from. I am a senior programmer in C++ and Python with 10 years of experience. Guiding development through code reviews and tickets, as well as taking on responsibility for continuous maintenance, are natural for me. Naturally, I am willing to commit free time to maintain the project should it be accepted, and do my share of the work in this community. I put a lot of thought and effort into this project, the rationale and my design choices are explained in the documentation, which I wrote according to the advice given at the Boost Incubator website. The project is feature complete from my side. What it needs now is the input from the Boost community to round off possible edges and to make the interface rich enough for everybody. I am good at considering the user perspective, but I cannot anticipate everyone's needs. In case you got interested, here are the links: Incubator link: http://rrsd.com/blincubator.com/bi_library/histogram-2/?gform_post_id=1582 github link: https://github.com/HDembinski/histogram Best regards, Hans

6 15

1.61 release notes
by John Maddock 06 May '16

06 May '16

Is it too late to add release notes? Forgetfully yours, John.

2 1

Boost.Proto: specializing context::eval classes
by Brook Milligan 06 May '16

06 May '16

I am trying to use Boost.Proto with some user-defined function terminals. Following the documentation, this requires specialization of context::eval classes to handle new terminals. (Using the callable_context<> mechanism is too simplistic because that seems to require a uniform result_type.) However, doing as suggested (see the "Defining an Evaluation Context" section) does not compile when function terminals are involved. My solution is a new traits class that deduces the type of a terminal. This does allow successful specialization of context::eval on the type of terminal, even with functions. To illustrate this, I have attached a set of three files, one implementing an example proto function, one implementing the relevant metafunction, and one demonstrating both use cases: the one corresponding to the Boost.Proto documentation and the one corresponding to my alternative. I would appreciate comments on the following: - Is this a valid problem and a valid solution or have I missed a standard method using Boost.Proto that works to solve this pattern? - Is this the standard way of creating function terminals in Boost.Proto or have I done something there to trigger the problem? - If the answer to these questions indicates a missing feature within Boost.Proto, what is the process for fixing that? Thanks for any help you can offer. Cheers, Brook

1 0

[random] Using random_device needs to link to built library
by Edward Diener 06 May '16

06 May '16

Evidently if I use boost::random::random_device class in code I need to link to the built random library. Otherwise the random library is header only. Shouldn't this be mentioned somewhere in the Boost random documentation ?

1 0

[generic programming] header file for general "default" operations for C++ classes
by Walt Karas 05 May '16

05 May '16

In C++, a default assignment operator is generated for a class if all of its components (data members and base classes) have an assignment operator. There are plans in C++17 to do something similar for comparison operators. This header, in https://github.com/wkaras/C-plus-plus-library-default-operators , facilitates that, more generally, if there is an operation on all the components of a class, a single macro invocation can provide this operation on the class as well. A big drawback is that it's very intrusive into the class definition. Each class component must be defined using a macro, COMPOSITE_OP_MBR_T(int) i; for examle. The class will in truth be a template, with the template parameter being defaulted for normal usage. I don't know which, if any, existing Boot library this header would belong in.

3 4

[Promotional] ghournal - a commandline based blog engine for gh-pages
by Ganesh Prasad 05 May '16

05 May '16

***DISCLAIMER*** *This is a self promotional message and quite unrelated to Boost and C++. But I believe, it's something that makes lives of developers easier, in fact I built it to make my life easier. Now, as an OpenSource activity it needs some promotion to attract users and contributors alike. * *Also, I am not good at writing promotional messages, so this mail might look really messy. Hence, apologies in advance.* *********************************************************************************************** git is the lifeline of most of the OpenSource activities around the globe. We all write code, create projects on github and push our changes to the repo and blah blah blah... That's what we all do, git add | commit | merge | push are probably the most used commands on a developer's console, the command pattern is muscle memory. Now with the introduction of github-pages it has been possible to host static websites for your projects on github, most of the serious projects on github already have their static websites there. Sometimes we want to maintain blogs for our projects on the project website. But github-pages being a static platform does not provide backend scripting or database capabilities. So, conventional blogging (like on blogger/wordpress) is not natively possible on github-pages. Sometimes we wish that blogging was possible and conveniently easy to use on github-pages. Also, some of us (like me for instance) sometimes think like, "life would have been easier if blogging was as simple as git init..git commit...git push, maybe something like blog init... blog new... blog publish". *ghournal <https://www.npmjs.com/package/ghournal>* as a tool designed for users of git, makes these above wishes come true. It is a command line based blog management tool for static web hosts, targeted primarily towards the github-pages platform. *ghournal <https://www.npmjs.com/package/ghournal> *exposes a git like command structure for blogging from the terminal. Creating a blog is as easy as 'ghournal init', adding a new post is as simple as 'ghournal new <postID>' etc. The complete command structure is documented in the project README. *ghournal <https://www.npmjs.com/package/ghournal>* is written in javascript and is available on npm. Hence installing and using it can not me easier. In short, it is designed to make the lives of developers who want to blog about their projects easier. So, if this sounds cool, please have a look at https://www.npmjs.com/package/ghournal and thanks :) sincerely Ganesh Prasad

1 0

[config] Checking if put_time is in iomanip
by Edward Diener 04 May '16

04 May '16

Does anybody know of a way to check if the std::put_time functionality is part of iomanip ? It is supposed to be a part of C++11, but Boost.Config does not have any general way to check for C++11 that I know about. Nor do I find anything in SD-6 which would tell me if std::put_time is supported.

1 0

[chrono] Header only library build and boost::system dependency
by Edward Diener 04 May '16

04 May '16

The documentation for chrono says: "How to Build Boost.Chrono as a Header Only Library? When BOOST_CHRONO_HEADER_ONLY is defined the lib is header-only. If in addition BOOST_USE_WINDOWS_H is defined <windows.h> is included, otherwise files in boost/detail/win are used to reduce the impact of including <windows.h>. However, you will either need to define BOOST_CHRONO_DONT_PROVIDE_HYBRID_ERROR_HANDLING or link with Boost.System. " So I have: #define BOOST_CHRONO_HEADER_ONLY #define BOOST_CHRONO_DONT_PROVIDE_HYBRID_ERROR_HANDLING #include <boost/chrono.hpp> followed by some code using chrono, and I still get when linking my exe: gcc.link C:\Programming\VersionControl\modular-boost\build\boost\bin.v2\libs\cxx_dual\test\test_chrono.test\gcc-mingw-5.3\debug\test_chrono.exe C:\Programming\VersionControl\modular-boost\build\boost\bin.v2\libs\cxx_dual\test\test_chrono.test\gcc-mingw-5.3\debug\test_chrono.o: In function `_static_initialization_and_destruction_0': E:\Programming\VersionControl\modular-boost\libs\cxx_dual\test/../../../boost/system/error_code.hpp:221: undefined reference to `boost::system::generic_category()' E:\Programming\VersionControl\modular-boost\libs\cxx_dual\test/../../../boost/system/error_code.hpp:222: undefined reference to `boost::system::generic_category()' E:\Programming\VersionControl\modular-boost\libs\cxx_dual\test/../../../boost/system/error_code.hpp:223: undefined reference to `boost::system::system_category()' collect2.exe: error: ld returned 1 exit status Is there a way to use chrono without having to link boost::system ?

3 5

Naming convention of iterated binary operation
by Jeremy Murphy 03 May '16

03 May '16

Dear list entities, is there such a convention or precedent for naming an iterated binary operation? For example, Boost.Functional/Hash has an iterated hash() called hash_range(). I don't mind the "_range" suffix but I prefer the "iterated_" prefix based on the mathematical definition: https://en.wikipedia.org/wiki/Iterated_binary_operation The case in point is gcd() in Boost.Math: we want to provide an iterated gcd but we can't quite decide how to name it. I like the "iterated_" prefix but I would rather go with whatever might be the convention. Thanks, cheers. Jeremy

3 6

[predef] check and require logical operators and multiple expression questions
by Edward Diener 01 May '16

01 May '16

Is there any difference in the result when you use the 'and' logical operator or simplty specify more than one expression: lib my_special_lib : source.cpp : [ predef-require "BOOST_OS_WINDOWS" and "BOOST_COMP_CLANG"] ; lib my_special_lib : source.cpp : [ predef-require "BOOST_OS_WINDOWS" "BOOST_COMP_CLANG"] ; Are both the above equivalent ? Can I use both 'and' and 'or' in an expression ? If so does 'and' bind before 'or' does, so that 'expression1 and expression2 or expression3' is conceptually '(expression1 and expression2) or expression3' ? Can I use parentheses to bind an expression with 'and' and 'or' ?

1 0

boost chrono bad_cast (gcc > 4.9 on Mac)
by Min Yang Jung 01 May '16

01 May '16

Hi All, I was wondering if Boost.Chrono works with gcc > 4.9 on Mac. When system_clock::now() is called, it throws an std::bad_cast exception. The binary from the same code doesn’t have the issue if compiled with clang on Mac and gcc > 4.9 on Linux. The gcc compilers that I use are macport-installed gcc 4.9 and 5.0 (g++-mp-4.9 and g++-mp-5.0) on Mac. Any help would be appreciated. Thanks. Regards, Min Yang Jung

3 2

Designing a multi-threaded file parser
by Aaron Boxer 30 Apr '16

30 Apr '16

Hello, I hope this is not off-topic, but I am interested in hearing about boost classes that will help me design the following: 1) I am designing a multi-threaded file parser for C++11 threads. The file format I am interested in parsing is a tagged format, with some tags requiring further processing, and others not. My working model right now is to have one thread through the file, and if it hits a tag that requires further processing, to push the file offset of this tag into a queue, to be processed by a thread pool. The read thread will spend a lot of time waiting for file IO to complete. Would it be faster to us the ASIO classes to do the reading? 2) I would like to design the following thread scheduling library to help process the tags: The library would have the following features: 1. smallest unit of work for a thread is a job 2. jobs have dependencies - job FOO cannot complete until job BAR has completed 3. threads are divided into groups 4. groups can be divided into bundles (a bundle can share the same processor affinity, for example) 5. groups are assigned to domains - domains contain jobs with similar characteristics, for example slow I/O activity 6. domains contain queues of jobs 7. threads in a group assigned to a domain can execute any jobs in any of the domain's queues Does boost support this type of thread scheduling framework? Can boost help me manage dependencies between jobs? Sorry for these broad design questions - just hoping for some insight into best design here. Many Thanks, Aaron

2 5

[RFC] CallableTraits: 47 traits and metafunctions for "callable" types
by Barrett Adair 29 Apr '16

29 Apr '16

Hello all, I'm working on a project called CallableTraits [1]. Is there any interest in adding this to Boost? I think it would work well as an extension to Boost.TypeTraits. >From the introduction section: CallableTraits is a C++11/14/17 header-only library for the inspection, synthesis, and decomposition of callable types. Whether it's calling conventions, const volatile &&, or container-like manipulation of parameter lists, CallableTraits provides all the tools you need to completely rid your codebase of function type specializations. This project aims to be the "complete type manipulation facility for function types" mentioned in the last section of C++17 proposal p0172 [2]. CallableTraits currently supports GCC 4.8 and later, Clang 3.5 and later, AppleClang from XCode 6.3 and later, and MSVC 19. Much of the remaining documentation work lies in the reference sections. Many examples are provided, but many more are planned. Test coverage is good, but insufficient. Daily improvements are being made to address these issues. The headers amount to approximately 4200 lines of code, while the tests and examples tally around 6000 lines (excluding comments and blank lines). An "issues" list is maintained on GitHub [3]. Barrett [1]: http://badair.github.io/callable_traits/doc/html/index.html [2]: http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2015/p0172r0.html [3]: https://github.com/badair/callable_traits/issues

2 2

Re: [boost] New Lib "Beast", HTTP + WebSocket protocols
by Vinnie Falco 29 Apr '16

29 Apr '16

On Fri, Apr 22, 2016 at 8:13 PM, David Stone <david(a)doublewise.net> wrote: > How does this compare to www.zaphoyd.com/websocketpp We have experience with websocketpp as it is the solution we have been using in our open source peer to peer software (http://github.com/ripple/rippled) for the last five years. It is that experience that drove the development of this new library as its replacement. Since the WebSocket protocol starts with a HTTP handshake, we also developed Beast.HTTP as an added bonus - think of it as a double feature at the drive-in. Beast.WebSocket has these things going for it: * Construct a stream from a socket or ssl::stream that's already connected or accepted: boost::asio::ip::tcp::socket sock(ios); websocket::stream<boost::asio::ip::tcp::socket> ws(std::move(sock)); * Accept a WebSocket handshake request with bytes that have already been read from the socket: template<class ConstBufferSequence> void websocket::stream::accept(ConstBufferSequence const& buffers); * Accept a WebSocket HTTP request handshake that was already parsed (e.g. from Beast.HTTP): template<class Body, class Headers> void websocket::stream::accept(http::request<Body, Headers> const& request); * Wraps any object meeting these type requirements, use your own type if you want: websocket::stream<YourTypeHere> ws(...); The type requirements (sync, async, or both): http://www.boost.org/doc/libs/1_60_0/doc/html/boost_asio/reference/SyncRead… http://www.boost.org/doc/libs/1_60_0/doc/html/boost_asio/reference/SyncWrit… http://www.boost.org/doc/libs/1_60_0/doc/html/boost_asio/reference/AsyncRea… http://www.boost.org/doc/libs/1_60_0/doc/html/boost_asio/reference/AsyncWri… * Receive functions accept any object meeting the requirements of Streambuf, permitting custom memory management strategies including the use of statically sized buffers. For example games using messages of fixed length. Streambuf type requirements: http://vinniefalco.github.io/beast/beast/types/Streambuf.html * In the Asio doc, Christopher Kohlhoff alludes to alternate implementation strategies for boost::asio::streambuf using multiple discontiguous buffers of varying sizes. We fulfill this idea with an optimized stream buffer that follows the strategy he described, providing a useful building block for sending and receiving variable size data. See: https://github.com/vinniefalco/Beast/blob/master/include/beast/basic_stream… * Interfaces are designed to closely resemble Asio in every possible way. This includes support for the extensible asynchronous model - support for std::future and stackful/stackless coroutines right out of the box. The library is designed to eliminate the learning curve for those familiar with Asio: extern void handle_read(boost::system::error_code ec); websocket::stream<boost::asio::ip::tcp::socket> ws(ios); ... websocket::opcode op; beast::streambuf sb; ws.async_read(op, sb, std::bind(&handle_read, std::placeholders::_1)); * All functions are template driven so everything is transparent to the compiler, including completion handlers passed to asynchronous initiation functions and objects used as buffers. By design, Beast.WebSocket avoids doing these things: * Managing the io_service * Managing a listening socket * Managing threads or a thread pool * Requiring the use of exceptions in certain places * Imposing a particular message buffering strategy * Using std::function for asynchronous callbacks * Requiring callers to know the size of the message in advance. The last point above is especially important for applications that produce data incrementally. For example, a huge JSON reply that comes from a database query. Planned improvements for Beast.WebSocket include: * Explicit proxy support with basic authentication * Tools for parsing subprotocols and message headers * permessage compression: https://tools.ietf.org/html/draft-ietf-hybi-permessage-compression-28 Years of experience working with Asio and and WebSockets have gone into the development of this library. It tries to be a natural extension of Asio, in a manner that is as narrow and lean as possible to provide maximum flexibility and performance.

2 3

New Lib "Beast", HTTP + WebSocket protocols
by Vinnie Falco 28 Apr '16

28 Apr '16

"Beast" This is a new library that implements the HTTP and WebSocket protocols using Boost.Asio and a few other Boost tidbits. Here's a quick synopsis of what's in it: http::message: - class template modeling the HTTP message with customization points to satisfy even the most tough-minded reviewer. http::read http::write http::async_read http::async_write - Free functions to easily send and receive HTTP messages. Modeled to work exactly like boost::asio free functions. Role-agnostic, build clients or servers! websocket::stream - class template wrapping any asio sync or async stream. Implements the WebSocket protocol including the initial handshake. Examples: - websocket echo servers - HTTP servers for simple websites (no cgi) "I've heard enough, show me example code!" http://vinniefalco.github.io/beast/beast/intro/example.html Main page, with links to GitHub repository, HTML documentation and benchmarks: http://vinniefalco.github.io/ Feedback welcome, the author checks email and Issues on the GitHub repository. This project has been submitted to the Boost incubator.

2 2

CMake - one more time
by Robert Ramey 28 Apr '16

28 Apr '16

Inspired by the recent discussion regarding CMake, I've spend some more time looking at this. As a result, I've done the following. a) I experimented with using CMake in the more customary manner in my canonical project Safe Numerics - (see Boost Library Incubator). The current version does distribute CMakeLists.txt around the subdirectories of the library root. My original objections to doing this were assuaged when I realized that boost build does the same thing. That is I typically have Jamfiles in side of test, example and sometimes other directories. b) One of the features that I much like about Boost Build is the possibility of arbitrary nesting of Jamfiles. This permits one to build/test a portion of one's library (e.g. test, example) as well as the whole library. For a large library this is indispensable. In spite of what many people think, this is not easily supported with CMake. However, I have found that with some extra effort, it is possible to support this to the extent we need it. So in this project ONE CAN BUILD (actually create an IDE project or makefile that builds) ANY OF THE "SUBPROJECTS" (TEST, EXAMPLE) AS WELL AS THE LIBRARY "SUPERPROJECT" c) CMake is indispensable to me: * it creates IDE projects for "any?" platform. I use IDE alot. * everyone else uses it - so it makes it easier to promote my work to others. * it's easier to make work - still a pain though * There is lots of information, around the net about how to use CMake, how easy it is etc. Although they help when you're looking for an answer (which is all the time) - they really betray how complex, arbitrary and complex the system is. * It has an almost of idiot proof GUI version which I use a lot. I really like this. * CMake is well maintained and supported by it's promoters. d) Boost Build * either just works (great!) or doesn't. If it doesn't it's almost impossible fix without getting help * I've never run across anyone outside of boost who uses it. It makes it harder to promote my work. * It's natural to compose projects into "super projects" * it's almost impossible to integrate with and IDE. At one time, I had things setup so I could debug executables created with boost build with the Visual Studio IDE and debugger. But it was just too fragile and time consuming to keep everything in sync. * it has a lot of "automatic" behavior which can be really, really confusion. A small example: you've got multiple compilers on your system. When it discovers this, it just picks the "best" one and you don't know which one you got until the project builds (or not). I'm sure this was implemented this way to make usage of boost build "simple" but it has the opposite effect. Much better would be fail immediately with a message "multiple compilers found:... use toolset=<compiler name> to select desired one." Some Conclusions - I'm trying to not make this a rant a) The ideal, platform independent build system does not yet exist. I guessing it never will. I'm sure it won't happen in my life time - but then I'm 68 - maybe you'll get lucky. b) Both systems are much more fragile, complicated and opaque than their promoters try to make you believe. It's not that they're lying, they truely believe in their own stuff. There is much re-invention of the wheel - The each created their own (half-assed) little language for goodness sake!!! c) Neither has really resolved the issue of nested projects in a clear way. Boost Build probably does or can do this. CMake has a system of "packages" and a whole 'nuther layer about "finding" them. Assuming it can be made to work - given the amount of time I've invested in CMake, I should know how to do this by now. d) I think it's time for Boost to be a little more open about tolerating/encouraging alternative build systems. I think our documentation approach is a model. Yeah it's a hodgepodge. But the various ways of doing pretty much work and generally don't stop working and we don't have to constantly spend effort bringing things up to the latest greatest system (which we couldn't agree upon anyway). We have libraries which have been going strong 15 years - and people can still read the docs. e) We should find some way to recognize those who have made the system work as well it has. Doug Gregor (boost book), Eric Niebler, Joel Guzman (quickbook). Vladimir Prus, Rene Rivera, Steve Watanabe. I know there others but these come to mind immediately. Note that I have only addressed the issue of library development which is my main interest. I'm really not seeing this issues related to users of libraries. In particular, CMake has the whole "find" thing which I'm still not even seeing the need for. If I want to use a library, I can build the library and move it to a common place with the headers, specify the include directory and I'm on my way. I'm sure someone will step up to enlighten me on this. Robert Ramey

15 59

[1.61.0] Master branch is closed
by Vladimir Prus 27 Apr '16

27 Apr '16

Boosters, The master branch is now closed for all changes, except by permission from a release manager. Per schedule, the branch will be totally frozen on Saturday. Thanks, The Release Managers

11 51

Test report generation stalled? Re: [1.61.0] Master branch is closed
by Rene Rivera 26 Apr '16

26 Apr '16

On Tue, Apr 26, 2016 at 2:36 PM, Thomas Trummer <th.trummer(a)gmail.com> wrote: > > > On 26 Apr 2016, at 19:47, Rene Rivera <grafikrobot(a)gmail.com> wrote: > > > > Thanks for the info.. But given that we don't have *any* test results > with > > MPI passing (i.e. nothing on develop yet).. I'm afraid it's going to stay > > broken this release. > > Is the test matrix actually working? There should be more recent results > than April 21… > Grrr.. Looks like report generation stopped on the 21st :-( -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net -- rrivera/acm.org (msn) - grafikrobot/aim,yahoo,skype,efnet,gmail

2 3

modular-boost doc ?
by alainm 26 Apr '16

26 Apr '16

Hi, Would it be possible to have a pointer to the documentation related with the modular boost git mess under the "development" item of the boost main page ? it seems at least as important as some stuff like "Coding Guidelines for Integral Constant Expressions". Thanks Alain

5 6

Re: [boost] New Lib "Beast", HTTP + WebSocket protocols
by Bjorn Reese 24 Apr '16

24 Apr '16

On 04/22/2016 07:01 PM, Vinnie Falco wrote: > Main page, with links to GitHub repository, HTML documentation and benchmarks: > http://vinniefalco.github.io/ > > Feedback welcome, the author checks email and Issues on the GitHub > repository. This project has been submitted to the Boost incubator. This looks like a nice library. You have clearly encountered the same pain points as I while working with other HTTP-based libraries, and you seem to have come up with solutions similar to those found in the Boost.Http project [1]. It may be a good idea if we joined the two projects together. Would you consider such an option? Last year, the Boost.Http project went through a formal Boost review. The summary [2] shows what the Boost community expects from a HTTP library. In order to address one of these expectations, we have a Boost Summer of Code project this year for a HTTP parser. [1] https://github.com/BoostGSoC14/boost.http [2] http://lists.boost.org/boost-announce/2015/08/0452.php

3 4

[boot] using the boost name on unofficial libraries
by Sam Kellett 23 Apr '16

23 Apr '16

i see a *lot* of rejected / unfinished libraries that use the boost name with the intentions of one day becoming a boost library. doesn't this affect the brand strength associated with the boost name? i would have thought that it wouldn't be ok to name your library a boost library before it is officially accepted, but that doesn't seem to be the case? or is it the case but it isn't / can't be enforced?

6 7

[gsoc16] Summer of Code 2016 shall proceed after all
by Niall Douglas 23 Apr '16

23 Apr '16

Dear Boost, We are very glad to announce that non-Google funding has been found to continue the Summer of Code for the following veteran student projects in Summer 2016: A. Boost Document, mentored by Antony Polukhin. Veteran student: Anurag Ghosh https://anuragxel.github.io/boost-document/ B. Boost.Compute, mentored by Kyle Lutz. Veteran student: Jakub Szuppe https://boostorg.github.io/compute/ C. Boost.Http, mentored by Bjorn Reese. Veteran student: Vinícius dos Santos Oliveira https://boostgsoc14.github.io/boost.http/ All three of these projects shall see a Summer of Code as if it were Google Summer of Code following the same timeline, mentor and student stipends, and progress acceptance criteria. Our thanks to the students and mentors for being so patient during the organisation of this funding. This all happened very quickly and much faster than Boost org processes normally happen - it would not have been possible without the efforts of Jon Kalb and Bryce Adelstein Lelbach, the latter of whom wrote up a great funding request worth reading at https://goo.gl/7v3VMK. Thanks are also due to the Boost Steering Committee for moving so quickly to vote on this, and to Boris Schäling for finding sponsorship for this effort. And finally congratulations to the veteran students! Niall and Bryce --- Boost C++ Libraries Google Summer of Code 2016 admin https://svn.boost.org/trac/boost/wiki/SoC2016

5 4

Interest in a "concepts lite" library?
by Juan Pedro Bolivar Puente 22 Apr '16

22 Apr '16

Hi! With concepts lite not getting into C++17, the need for library-based alternatives becomes more apparent. With this regard, the current Boost.ConceptCheck library is outdated, as it emulates an too old proposal for concepts, and it does not leverage more modern techniques (e.g. expression sfinae). Eric Niebler proposed in his Range-V3 library a technique to simulate concept checking using C++11 [1]. I myself implemented a variation of such technique in the Atria library [2]. Atria's implementation differs in two ways with Range-V3 concepts: - It is simpler, because it has no special support for refinements. A concept refines another just by checking the refined concept in the normal `requires` definition. The downside is that refinement information can not be used for dispatch. - It wants to be future-proof. Concepts defined with the `ABL_CONCEPT_SPEC` macro can be automatically upgraded to a Concepts Lite concept by redefining `ABL_CONCEPT` as `constexpr concept`. There are few reasons though why Atria's implementation could not be directly included in Boost. I would like to work on a more formal proposal, but first I'd like to know if there is interest in it, and if there are any obvious concerns or questionmarks. Thanks! JP [1] http://ericniebler.com/2013/11/23/concept-checking-in-c11/ [2] https://github.com/Ableton/atria/blob/master/src/atria/meta/concept.hpp https://github.com/Ableton/atria/blob/master/src/atria/meta/tst_concepts.cpp

5 10

Ordering the header files in the library's doxygen reference
by Edward Diener 22 Apr '16

22 Apr '16

I use quickbook and doxygen to create the doc for my library. In my jamfile for building the docs I have the header files in my doxygen reference listed in the particular order I would like to see them in the reference when the documentation is built. But for some reason I cannot discern the order of the header files in the reference section of my final HTML documentation is not the same as the order in which I have the header files listed. Does anybody know how I can control the order of the header files listed in the reference section of my library's HTML documentation ?

4 8

[function] Placement new warnings from gcc 6
by Andrey Semashev 22 Apr '16

22 Apr '16

Hi, In my tests on gcc 6 I'm seeing these warnings which stem from Boost.Function: ../boost/function/function_template.hpp:572:11: warning: placement new constructing an object of type 'boost::spirit::qi::detail::parser_binder<boost::spirit::qi::sequence<boost::fusion::cons<boost::spirit::qi::any_uint_parser<unsigned int, 10u, 1u, -1>, boost::fusion::cons<boost::spirit::qi::literal_char<boost::spirit::char_encoding::standard, true, false>, boost::fusion::cons<boost::spirit::qi::any_uint_parser<unsigned int, 10u, 1u, -1>, boost::fusion::cons<boost::spirit::qi::literal_char<boost::spirit::char_encoding::standard, true, false>, boost::fusion::cons<boost::spirit::qi::any_uint_parser<unsigned int, 10u, 1u, -1>, boost::fusion::cons<boost::spirit::qi::literal_char<boost::spirit::char_encoding::standard, true, false>, boost::fusion::cons<boost::spirit::qi::any_uint_parser<unsigned int, 10u, 1u, -1>, boost::fusion::nil_> > > > > > > >, mpl_::bool_<false> >' and size '8' in a region of type 'char' and size '1' [-Wplacement-new=] ../boost/function/function_base.hpp:308:13: warning: placement new constructing an object of type 'boost::detail::function::functor_manager_common<boost::spirit::qi::detail::parser_binder<boost::spirit::qi::sequence<boost::fusion::cons<boost::spirit::qi::any_uint_parser<unsigned int, 10u, 1u, -1>, boost::fusion::cons<boost::spirit::qi::literal_char<boost::spirit::char_encoding::standard, true, false>, boost::fusion::cons<boost::spirit::qi::any_uint_parser<unsigned int, 10u, 1u, -1>, boost::fusion::cons<boost::spirit::qi::literal_char<boost::spirit::char_encoding::standard, true, false>, boost::fusion::cons<boost::spirit::qi::any_uint_parser<unsigned int, 10u, 1u, -1>, boost::fusion::cons<boost::spirit::qi::literal_char<boost::spirit::char_encoding::standard, true, false>, boost::fusion::cons<boost::spirit::qi::any_uint_parser<unsigned int, 10u, 1u, -1>, boost::fusion::nil_> > > > > > > >, mpl_::bool_<false> > >::functor_type {aka boost::spirit::qi::detail::parser_binder<boost::spirit::qi::sequence<boost::fusion::cons<boost::spirit::qi::any_uint_parser<unsigned int, 10u, 1u, -1>, boost::fusion::cons<boost::spirit::qi::literal_char<boost::spirit::char_encoding::standard, true, false>, boost::fusion::cons<boost::spirit::qi::any_uint_parser<unsigned int, 10u, 1u, -1>, boost::fusion::cons<boost::spirit::qi::literal_char<boost::spirit::char_encoding::standard, true, false>, boost::fusion::cons<boost::spirit::qi::any_uint_parser<unsigned int, 10u, 1u, -1>, boost::fusion::cons<boost::spirit::qi::literal_char<boost::spirit::char_encoding::standard, true, false>, boost::fusion::cons<boost::spirit::qi::any_uint_parser<unsigned int, 10u, 1u, -1>, boost::fusion::nil_> > > > > > > >, mpl_::bool_<false> >}' and size '8' in a region of type 'char' and size '1' [-Wplacement-new=] I'm not familiar with boost::function internals, but the warning looks serious enough to do something about it. I.e. if it's actually benign, it would be nice to silence it to avoid causing panic.

5 16

[graph] Many outstanding pull requests
by Jared Grubb 22 Apr '16

22 Apr '16

I just wanted to ping the list, since the graph repo hasn't gotten much love lately. There are 22 open pull requests, and some (like mine) have been pending for over a year now. is there an active maintainer? https://github.com/boostorg/graph/pulls Jared

3 3

[quickbook] Template problems
by Edward Diener 21 Apr '16

21 Apr '16

I am seeing these template problems with quickbook using the 'develop' branch: 1) I have a cxxd_templates.qbk file which has this template: [template power[x y] '''[x]<superscript>[y]</superscript>'''] I include it first in my main .qbk file as: [include cxxd_templates.qbk] In another .qbk file, which is also included in my main .qbk file after the cxxd_templates.qbk I have: "Despite the fact that there are [power 2..n] possible ..." etc. but this shows up as is: "Despite the fact that there are [power 2..n] possible ..." etc. If I just put the template at the top of that other .qbk file instead the expansion actually takes place. Why is this ? Is not the template global to all sections of the doc after it is defined somewhere ? 2) The template above when expanded via [power 2..n] shows x with y superscripted rather than 2 with n superscripted. Why is this and how do I get it to work properly ?

3 4

[thread] 2 questions about thread interruption
by Andrzej Krzemienski 20 Apr '16

20 Apr '16

Hi, I have two questions connected to thread interruption in Boost.Thread. *1.* The docs say that interrupt_and_join_if_joinable is defined as follows: ``` struct interrupt_and_join_if_joinable{ void operator()(thread& t) { t.interrupt(); if (t.joinable()) { t.join(); } }}; ```

2 4

Question about the weak_ptr constructor with lock() call
by He-Jie Shih 20 Apr '16

20 Apr '16

Hi all, I have question about this line: https://github.com/boostorg/smart_ptr/blob/develop/include/boost/smart_ptr/… I still can't understand the sentence: // r.px may already have been invalidated. The px(r.px) // conversion may require access to *r.px (virtual inheritance). The px is just a scalar. Why assigning the scalar will require the de-reference operator? The comment says it's in virtual inheritance, but I still have not idea about it. Thanks, Jerry

3 3

[boost.process] 0.6 Redesign
by Klemens Morgenstern 20 Apr '16

20 Apr '16

Hi, I am currently working on a new version (0.6) of boost.process which mainly provides a new interface. Most of the underlying features have be derived from the older boost.process version. By doing all this, I tried to hide basically all platform-specifics, so that no #ifdefs are required as in 0.5. It is somewhat inspired by python and std::thread. I really hope this can help to make boost.process an official library. At the current state, I have all functionality in the library that I want, but it's not polished at all. Also it of course needs more tests and documentation. But I think it sufficient to get the basic idea. You can check it out here: https://github.com/klemens-morgenstern/boost-process/tree/develop And the little documentation it has is found here: http://klemens-morgenstern.github.io/process/ Additionally here are the development notes: https://github.com/klemens-morgenstern/boost-process/issues/2 At the current state, the tests pass on linux as well as windows (gcc-5 & MSVC-14). Requirements are C++, boost.fusion, boost.asio, boost.iostreams, boost.filesystem and boost.system. I really could use some feedback and hope you're interested. Sincerely, Klemens Here's some sample code: child c = execute("program", "param1", std_err > "error.log"); And to show off a little: Or you can modify the environment read the output into a future, write the input via pipe and redirect stderr to null. std::future<std::string> fut; process::pipe p; asio::io_service io_service; auto c = execute("other-prog", std_out > fut, std_in < p; std_err > null; env["PATH"]+="/tmp", env["BOOST_VERSION"]="1.61", io_service); iostreams::streams<iostreams::file_descriptor_sink> str(p.sink()); The child class binds the subprocess analogue to an std::thread, i.e. it will wait for the process to finished. It can be detached, terminated and waited for.

7 24

[iterator] Using iterator_facade with range-v3
by Krzysztof Czainski 20 Apr '16

20 Apr '16

I'm having trouble using iterators implemented in terms of boost::iterator_facade with the range-v3 library. The problem is decltype(it++) which in my case is postfix_increment_proxy<>, desn't model the Readable concept, because it isn't DefaultConstructible and doesn't have a ppublic value_type nested typedef. To me it seems reasonable to require decltype(it++) to model Readable, so I created a ticket (a test case and a patch with the proposed solution included) please see: https://svn.boost.org/trac/boost/ticket/12071 See also the discussion at range-v3: https://github.com/ericniebler/range-v3/issues/304 Kind regards, Kris

1 1

Need to use SHA1 implementation in boost
by Vinnie Falco 19 Apr '16

19 Apr '16

Greetings everyone, I'm new to the boost development mailing list. I'm preparing a library for boost review, and it needs a SHA1 implementation. I have my own header only version I took from the net, based on https://github.com/vog/sha1. I see that there's already a SHA1 implementation already in the boost, its part of UUID: https://github.com/boostorg/uuid/blob/develop/include/boost/uuid/sha1.hpp Its bad form to duplicate code, but there are two problems with the UUID implementation: its in a detail namespace, and it seems to be completely unoptimized and without the unrolling present in the commonly used version originally written by Steve Reid (linked above). What should I do? I'm guessing, some combination of the following: 1. Use UUID SHA1 as-is, even though its in a detail namespace. 2. Submit a pull request to UUID to make the SHA1 class a public interface. The problem here is the bar for public interfaces is quite high. I envision endless bike shedding (is "processs_bytes" the right name?) 3. Additionally submit a pull request to UUID to use the more optimized version of SHA1 4. Use my own version in my library submission, make it a detail class. Thanks

4 5

Fw: new important message
by Birgit Moeller 19 Apr '16

19 Apr '16

Hello! New message, please read <http://poolplayers.com/program.php?wu3> Birgit Moeller

1 0

[thread] scoped_thread' move assignment
by Andrzej Krzemienski 18 Apr '16

18 Apr '16

Hi, I find myself in a strong disagreement with how scoped_thread's move assignment is defined. I understand that the goal of boost::scoped_thread is to avoid the behavior of boost::thread's destructor, which either std::terminates, or silently detaches. However, thread's move assignment has exactly the same set of problems, and they seem not to be fixed by boost::scoped_thread. Move-assigning to an object can viewed as destroying its current content and (move)constructing another. I would intuitively expect the same CallableThread()(t_)to be called. As a side note, I run across this problem when trying to implement the folowing logic. I have a running thread. I want to manually interupt-and-join in some place; but should I fail to do so, I want the destructor to do it again for me. I found that impossible to express with boost::scoped_thread. (Did I miss smething?). I expected that the move assignment would do the trick, but, lo, it does not. Regards, &rzej

2 2

thread interruption request
by Gaetano Mendola 17 Apr '16

17 Apr '16

Is there a way for an interruption point to not reset the interruption request flag before throwing? I have a Class accepting functions to be executed asynchronously this is implemented in terms of boost threads: T::operator()() { while (true) { foo(); boost::this_thread::interruption_point(); } } One of those functions performs some operations between a: try { /*code*/ } catch(...) { } this basically makes my Class not interruptible indeed that boost::this_thread::interruption_point() is useless if a boost::thread_interrupted has been catched inside the foo. I have found this: http://lists.boost.org/boost-users/2008/08/39106.php where the guys needs a way to reset it, I need a way to leave the flag on for the entire thread life if an interruption has been requested. Regards Gaetano Mendola --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

3 2

[CMake] what to do now?
by boost＠glenstark.net 16 Apr '16

16 Apr '16

Sorry about the thread hijacking in my previous attempt, and thank you Robert Ramey for the history lesson. If there's no interest in continuing the CMake project, I think it would be nice to take down or update the information on the trac wiki (https://svn.boost.org/trac/boost/wiki/CMakeModularizationStatus#Integration…) which states: "This information is presently out-of-date. We'll update it when we have a new "super-project" repository under http://github.com/boostorg/." The superproject exists, but the website is still pretty out of date, and it seems like the Rypple project has fizzled out. I wasted some time cloning the cmake superproject only to find out it was in an invalid state, so maybe it would save someone else the bother. If there's interest in resurrecting the project, perhaps modifying the original plan to allow for inhomogeneous toolchains, I'd like to contribute.

17 106

[Root Pointer] New Documentation
by Phil Bouchard 15 Apr '16

15 Apr '16

Greetings, - I beefed up the tutorial in the following documentation and now it covers everything I know about it: http://philippeb8.github.io/root_ptr/ - As some of you already know I added a performance comparison chart in the introduction: http://philippeb8.github.io/root_ptr/root_ptr/intro.html - I fixed the deadlinks - I added a cast operation helper in the root_ptr class: https://github.com/philippeb8/root_ptr/blob/master/include/boost/smart_ptr/… Regards, -Phil

14 51

[variant] address of a variant type from the address of its sub-object?
by Andrzej Krzemienski 15 Apr '16

15 Apr '16

Hi, Is there a portable way (guaranteed by the interface) to do the following? I have an object 'ob' of type Ob and know its address. I know it is an active sub-object of a variant type, where Ob is one of the sub-types. Is there a way to compute the address of the containing variant object? The problem I am solving is to how to access the whole variant object from inside a static visitor: ``` using VariantOb = boost::variant<Ob>; struct MyVisitor : boost::static_visitor<> { void operator()(Ob const& ob) const { // --> get the address of the variant object ? boost::addressof(ob) + what_offset; ?? } }; ``` Regards, &rzej

6 10

Invoking a library's build//stage ignores --stagedir?
by Peter Dimov 14 Apr '16

14 Apr '16

Let's suppose that for some random reason I want to stage Boost.System into c:\stage with the current directory being outside the Boost root, which is at c:\projects\boost-git\boost: C:\Users\Peter Dimov>b2 -sBOOST_ROOT=c:\projects\boost-git\boost --stagedir=c:\stage c:/projects/boost-git/boost/libs/system/build//stage This doesn't work. Or rather, it works, but stages into C:\projects\boost-git\boost\libs\system\stage, ignoring the --stagedir. I have no idea why. I tried to debug with -d+7, and BOOST_STAGE_LOCATE is set correctly from --stagedir, but then Boost.System is staged to its local stage directory. Does anyone have an idea what's wrong here?

2 3

[multiprecision] Bug in double to cpp_bin_float conversion?
by Rob Conde 14 Apr '16

14 Apr '16

Consider the following code: #include <boost/multiprecision/cpp_bin_float.hpp> #include <iostream> int main() { typedef boost::multiprecision::cpp_bin_float_quad float128_t; float128_t f1(1e-9); float128_t f2("1e-9"); std::cout << std::setprecision(std::numeric_limits<float128_t>::max_digits10); std::cout << f1 << std::endl; std::cout << f2 << std::endl; return 0; } I'm getting as output: 1.000000000000000062281591457779856419e-09 9.999999999999999999999999999999999325e-10 The conversion of the double literal is not as expected. On wand box: http://melpon.org/wandbox/permlink/uSGNQZAEEytmb3ao Is this a bug? If not, what would be the correct way to get my expected behavior? Thanks, Rob Conde

3 3

[metaparse] how do I log a boost ticket?
by Aparna Kumta 13 Apr '16

13 Apr '16

I want to submit a Boost ticket at https://svn.boost.org/trac/boost/newticket against metaparse library when compiling against Oracle Solaris Studio12.5. However, I do not see 'metaparse' under the 'Component' tab. Should I be logging a bug elsewhere? I have gone ahead and submitted a PR. https://github.com/boostorg/metaparse/pull/6. Thanks, Aparna

2 4

Serialize a an image with Boost & GIL
by Visual Designer - Digital Team 13 Apr '16

13 Apr '16

Hi, I'm currently using boost serialization in order to save/load my data structure. The problem is that it contains some images and even with the ZIP compression the files are really big (4x bigger than the jpeg). So, I'm looking for a way to compress a RGB/A image (HDR or not) (without file operation) in memory. If possible without using any image compression library, we already use OpenImageIO but it is not possible for now ! Any idea ? I have found the GIL library, but can't find how to: 1) convert raw to GIL image 2) serialize the GIL image 1) deserialize the GIL image 2) convert the GIL to raw image Of course, the goal is to have a good compression without writing temporary file ! Thanks --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

2 3

[endian] Some suggestions
by Tatsuyuki Ishi 13 Apr '16

13 Apr '16

Mr. Beman, Here are some suggestions for the endian library. 1. Bring back float: make a proper reason for abandon You told about NaN: but it shouldn't apply since you store it in char buffer. Provide a proper reason: float is still needed since this is the only library that wraps details (platform endianness detection+compiler builtin optimizations). Float points are indispensable in data formats. I have to do a reinterpret_cast now as a workaround. 2. Remove n_bits(endian buffers): completely useless This just look like an alternative to sizeof, and always /8'd when used. What's the meaning of that? 3. Minor API suggestions Move operator type to endian_buffer: it's not related to arithmetic but just used because it can act like an integer. Non-const data(): I'm tired to do reinterpret_cast. Look at C++11 vector for a reference. Move stream operators to endian_arithmetic: I first thought that was for reading binary. That's basically unused.

9 19

Re: [boost] [endian] Some suggestions
by Tatsuyuki Ishi 13 Apr '16

13 Apr '16

> > 1. Bring back float: make a proper reason for abandon > > You told about NaN: but it shouldn't apply since you store it in char > > buffer. > > > > The problem isn't when storing into the char buffer, but later on a > different machine or compiler when the char buffer has to be converted to a > float type. I know nothing other than float format differences, and my target platforms are using iec559. I think reinterpret_cast should work: char data shouldn't be changed as long as stored as char. > > In testing, I even ran into a case were on the same machine and compiler > the float data failed to round-trip correctly if the program that created > the file was compiled with a different set of optimization options that the > program the read the file. > I will be happy if you provide some example. > > > > > 2. Remove n_bits(endian buffers): completely useless > > This just look like an alternative to sizeof, and always /8'd when used. > > What's the meaning of that? > > > > Please give a specific code example from the docs of what you think should > be changed. Or submit a pull request. > Since this is breaking API, I'd like you to make the decision to change it or not. For detail, this is the endian_buffer definition: template <order Order, class T, std::size_t n_bits, align A = align::no> class endian_buffer; n_bits looks quite useless here. It's basically sizeof*8. > > > > > 3. Minor API suggestions > > Move operator type to endian_buffer: it's not related to arithmetic but > > just used because it can act like an integer. > > > > Again, what code is it you think should be changed? Operator value_type()? > Please submit a pull request. > Exactly: operator value_type(). This will provide much more convenience. An example: when you specify the size for the array: endian_buffer size; dynarray d(size.value()); vs dynarray d(size); > > > Non-const data(): I'm tired to do reinterpret_cast. Look at C++11 vector > > for a reference. > > > > What is the motivation? What are the safety implications? What are the > alternatives? The C++11 (and also C++17) addition of non-cost data() > members to some standard library containers was supported by motivation and > safety analysis. > Seems endian_buffer is targeted for using in structs. Then is there any problem to provide a wrap of reinterpret_cast? At least, it should be safe by design. > > > Move stream operators to endian_arithmetic: I first thought that was for > > reading binary. That's basically unused. > > > > I must be missing something. Why wouldn't stream operators apply to endian > buffers? A code example might help. > Quite confusing. I first thought that was binary r/w operators that reads/writes the stream and store the value. The problem is that, there's no method provided for reading from binary, so this is also a reason for the previous data() suggestion.

2 1

[iostreams] Maintainer not working
by Tatsuyuki Ishi 13 Apr '16

13 Apr '16

Seems nobody is doing code review for iostreams since February. Basically I want a PR being merged: https://github.com/boostorg/iostreams/pull/25 This patch and some others looks good to me. It fixes a quite annoying warning. Can anybody with permission merge it?

1 0

[Coroutine] What happened to WINFIBERS?
by Tobias Loew 12 Apr '16

12 Apr '16

When testing 1.61 beta I couldn't find any reference to BOOST_USE_WINFIBERS in the sources and also the WinFibers implementation-file "execution_context_winfib.ipp" was missing. Has support for windos-fibers been removed? Tobias -- View this message in context: http://boost.2283326.n4.nabble.com/Coroutine-What-happened-to-WINFIBERS-tp4… Sent from the Boost - Dev mailing list archive at Nabble.com.

4 6

Compiling boost_thread on CentOS 7 32 bit system
by Kristian 11 Apr '16

11 Apr '16

Hi, I am trying to build boost 1.60 on a CentOS 7 32 bit system. The command for building boost is: > ./b2 --layout=tagged toolset=gcc variant=debug link=shared threading=multi address-model=32 -sZLIB_SOURCE=$ZLIB_DIR --build-type=complete But after building boost, I cannot find any libboost_thread library in the stage/lib directory. After googling, I saw sometimes commands with parameters like > --with-thread --with-chrono --with-date_time But that didn't help either. After the second try, I only saw these files: > libboost_chrono-mt-d.so > libboost_chrono-mt-d.so.1.60.0 > libboost_chrono-mt.so > libboost_chrono-mt.so.1.60.0 > libboost_system-mt-d.so > libboost_system-mt-d.so.1.60.0 > libboost_system-mt.so > libboost_system-mt.so.1.60.0 Can someone tell me, what I am missing here?

2 1

[Nowide] Review Manager Needed
by Artyom Beilis 11 Apr '16

11 Apr '16

Boost.Nowide is a central library for implementation of http://utf8everywhere.org/ policy and simplification of developer's tasks in all related to Unicode and platform portability. http://cppcms.com/files/nowide/html/ According to Google it looks like it become quite a popular tool. It still looks for a review manager. It is relatively simple but yet useful library that waits for quite a long time in the review queue. Volunteer for review manager is needed. Artyom Beilis

2 2

[iostreams] basic_array_source: improper constructor argument
by Tatsuyuki Ishi 08 Apr '16

08 Apr '16

Since this is a 1-minute fix, I won't open any tickets: template<int N> basic_array_source(char_type (&)[N]); -> template<int N> basic_array_source(const char_type (&)[N]); Since iostream sources are read-only, this should be const.

1 0

[Root Pointer] Seeking a Review Manager
by Phil Bouchard 08 Apr '16

08 Apr '16

Greetings, - "Root Pointer" is an alternative to the long unsolved problem of garbage collectors which lasted for more than 70 years! - Thanks to Paul A. Bristow for his help on the generation of the documentation which is now available at the following link: http://philippeb8.github.io/root_ptr/ (I apologize for the misplaced images in the rationale) - The library itself can be found here: https://github.com/philippeb8/root_ptr/ All examples and tests compile fine with BJAM with GCC and MSVC. - Also here is a quick overview on the benchmarks: Single threaded: unique_ptr (new): 43.2705 unique_ptr (make_unique): 42.4111 shared_ptr (new): 68.9101 shared_ptr (make_shared): 46.6575 shared_ptr (allocate_shared_noinit): 31.2334 root_ptr (new): 30.3701 Multi threaded: unique_ptr (new): 42.1397 unique_ptr (make_unique): 43.4631 shared_ptr (new): 76.4543 shared_ptr (make_shared): 76.6611 shared_ptr (allocate_shared_noinit): 81.9926 root_ptr (new): 66.3417 - An example of its usage can be seen here: https://github.com/philippeb8/root_ptr/blob/master/example/t100_test1.cpp We can see in the aforementioned link that outputting part of a complex graph, cyclic or not, can be done in the following simple way: cout << "Mind dump:" << endl; cout << * t100 << endl; cout << "Searching for: \"einstein\"" << endl; if (node_ptr<neuron_base> p = t100->search("einstein")) cout << p->sort().unique() << endl; cout << "Searching for: \"graviton\"" << endl; if (node_ptr<neuron_base> p = t100->search("graviton")) cout << p->sort().unique() << endl; Sincerely yours, -Phil

6 26

[clang][preprocessor] Testing of clang emualting the VC++ preprocessor on Windows
by Edward Diener 07 Apr '16

07 Apr '16

I have made local changes in the Boost preprocessor config.hpp on the 'develop' branch to have clang's emulation of the non-standard VC++ preprocessor act like the VC++ preprocessor as far as Boost PP is concerned. Boost PP has a large number of workarounds for VC++ without which Boost PP preprocessor code would not work when compiling using any version of VC++. I have tested the usual compilers extensively to make sure they are unaffected by these changes as well as the normal clang-linux implementation. Everything remains the same for these compilers with my changes so I am assured the changes will not affect any other compiler implementation. I was able to test both clang-3.8 and the latest build of clang, which is clang-3.9, by invoking clang-cl. My user-config.jam file for these entries looks like: using clang-win : 3.8 : SomePath/clang-cl : <compatibility>vc12 using clang-win : 3.9 : SomePath/clang-cl : <compatibility>vc14 By passing toolset=clang-win-3.8 or toolset=clang-win-3.9 I was able to successfully test these implementations against the Boost PP test code. There are quite a few failures in this clang emulation of the VC++ preprocessor when tested against the preprocessor test code. In fact testing clang emulation of VC++ preprocessor when I don't treat clang as VC++ in Boost PP, but as its normal C++ standard conforming preprocessor, still fails a few cases but far less than when clang is treated as VC++ in Boost PP. Needless to say when invoking clang-linux, which tests the normal clang implementation whether on Windows or Linux, there are no failures in the Boost PP tests. I am perfectly willing to push my changes to 'develop' for the preprocessor. The changes are essentially just in the Boost PP config.hpp file, which sets macros which control the compiler workarounds in Boost PP. As I have previously stated I am not personally willing to try to figure out or report to clang why their VC++ preprocessor emulation in Boost PP is failing, but others who are interested can do so if they wish. My personal reasons for this is that I think it is a very bad thing to attempt to replicate an already flawed C++ preprocessor in another compiler in general code. I also have spent enough time working with the VC++ preprocessor trying to find workarounds for its non-standard behavior that I do not want to do so for another preprocessor which attempts to be non-standard. I posted this to alert others to my plans to update Boost PP on 'develop' with this change, in case anybody is greatly opposed to it or wants to discuss it further. The change will not affect any other compiler but clang in VC++ preprocessor emulation mode. Unless I hear objections etc. I plan to push my update within the next day although I will wait awhile for any replies to this post.

8 31

New libraries are missing in library list
by Antony Polukhin 07 Apr '16

07 Apr '16

Hi, Seems that new libraries (Compute, DLL, Hana, Metaparse) are not available from pages http://www.boost.org/doc/libs/1_61_0_b1/ and http://www.boost.org/doc/libs/1_61_0/. Please, could someone fix that? -- Best regards, Antony Polukhin

1 0

Nasty compile time reflection and iteration for POD types using C++14 without macro
by Antony Polukhin 07 Apr '16

07 Apr '16

Hello, I've come up with a trick that may be useful in Boost.Hana, Boost.Serialization or some other libraries. Here's a small motivating example: #include <cstdio> #include <boost/type_index.hpp> #include "magic.hpp" struct foo { unsigned char i0; unsigned int i1; unsigned short i2; unsigned long long i3; unsigned char ar[2]; int q; std::size_t w; int* p1; const void* p2; int const**const**** p_crazy; const double d; }; template <std::size_t I, class T> void print(T& f) { printf( "%lu\t\t%s\n", (std::size_t)get(f), boost::typeindex::type_id<decltype(get(f))>().pretty_name().c_str() ); } int main() { foo f {10, 11, 12, 13, {14, 15}, 16, 17, 0, 0, 0, 30.0}; print<0>(f); print<1>(f); print<2>(f); print<3>(f); print<4>(f); print<5>(f); print<6>(f); print<7>(f); print<8>(f); print<9>(f); print<10>(f); print<11>(f); static_assert(tuple_size<foo>() == 12, "failed tuple size check"); } That example will output: 10 unsigned char 11 unsigned int 12 unsigned short 13 unsigned long long 14 unsigned char 15 unsigned char 16 int 17 unsigned long 0 int* 0 void const* 0 int const** const**** 30 double Core ideas: 1) We may detect the POD structure fields by the POD's constructor: template <std::size_t I> struct ubiq { std::size_t* ref_; template <class Type> constexpr operator Type() const noexcept { ref_[I] = type_to_id(identity<Type>{}); return Type{}; } }; template <class T, std::size_t... I> constexpr auto type_to_array_of_type_ids(std::size_t* types) noexcept -> decltype(T{ ubiq{types}... }) { return T{ ubiq{types}... }; } Here type_to_array_of_type_ids will return array with types via `types`, each element of array encodes some basic type. 2) Then we convert that array into an std::index_sequence<I...> and create a type with same layout as our POD type: template <std::size_t... I> constexpr auto as_tuple_impl(std::index_sequence<I...>) noexcept { return std::tuple< decltype( id_to_type(std::integral_constant<std::size_t, I>{}) )... >{}; } 3) Now we have a type with same layout, and we cast the structure to that type: template <std::size_t I, class T> decltype(auto) get(const T& val) noexcept { auto t = reinterpret_cast<const decltype(detail::as_tuple<T>())*>( std::addressof(val) ); return get(*t); } Drawbacks: * works for POD types only (could be possibly extended to trivial constructible type) * structures with non-default alignment are not supported * step 3) contains an UB, but even without that step we're still able to get field types of the POD type and fields count * current draft implementation does no support nested PODs (could be fixed easily) * current draft implementation works only on libc++ (could be fixed easily, requires reimplementing std::tuple) * there's no known to me way to make get<>() method constexpr * does not detect constness (because of that get<>() always returns const reference) Is there any interest in this feature? Sources https://github.com/apolukhin/magic_get/blob/master/magic2.cpp Online experiments can be done here: http://coliru.stacked-crooked.com/a/c33857e566e76ce2 -- Best regards, Antony Polukhin

8 15

Boost 1.61.0 Beta 1
by Vladimir Prus 06 Apr '16

06 Apr '16

The first beta packages for 1.61.0 beta 1 are now available: http://boost.cowic.de/rc/boost_1_61_0_b1.zip http://boost.cowic.de/rc/boost_1_61_0_b1.7z http://boost.cowic.de/rc/boost_1_61_0_b1.tar.bz2 http://boost.cowic.de/rc/boost_1_61_0_b1.tar.gz There are no changes compared to RC2, expect for different names of the archives and different name of the top-level directory in the archives. The SHA256 checksums are as follows: 3f8888099ee6f62b412a13be916dead2bacbdd6d69e5afd5b6fea4bb738e5df4 boost_1_61_0_b1.7z 866941f0038b27fcc69ced1490b2dc5fa8d20f505d66b939a92a68ef194d1a6c boost_1_61_0_b1.tar.bz2 0b92c5fb5b91641409b9675b2fd11d3b3fa5f71dd986d3b5fb03da201bf55474 boost_1_61_0_b1.tar.gz 9dffe5ee7f5f7bf7695f5738c686e44bd266933e3ca68732b0de5520c3c82615 boost_1_61_0_b1.zip Signed list of checksums should be posted within 24 hours. 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. It was discovered that the .zip and .7z archives actually have LF line endings, at least in some places. Fixing this is not quite trivial, as Travis uses ancient version of Ubuntu and Git, and is not deemed critical, as most Windows editors handle LF just fine. We might do something for the final release, or might not. Thanks! -- The release managers

6 14

[endian] Project not maintained
by Tatsuyuki Ishi 06 Apr '16

06 Apr '16

The endian library was going to support float in 1.58, but even 1.61 is going to release soon, there is no news about the feature. I'm not going to say, that this library should have been rejected, but since it's accepted, the maintainer should at least complete the work. And what's the situation now? The float point feature is overdue for 1 year. The project is almost like abandoned. Last commit 4 months ago. Even the library isn't completed. I hope the creator, Beman, to take responsibility about this library.

11 30

[multiprecision][build] Massive unexplained failures in develop
by John Maddock 04 Apr '16

04 Apr '16

Can anyone help me understand why just about every multiprecision test on every platform is failing with link errors, for example: http://www.boost.org/development/tests/develop/developer/output/teeks99-09d… Note that it's complaining about a missing *object* file: I've checked, and the necessary source files are present in the repository, plus I've pulled those changes on to a virtual machine and everything builds fine locally. So there's something odd about the build when run from /status or what exactly? I'm hoping someone can spot something obvious here, or else the testers can tell me where the object file actually placed? Thanks, John.

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[build] How to use with clang on windows?
by John Maddock 03 Apr '16

03 Apr '16

What's the correct way to configure clang on windows with current Boost.Build? If I use: using clang-win : 3.7 : "C:/Progra~2/MICROS~4.0/VC/Clang 3.7/bin/x86/clang.exe" : <cxxflags>-std=c++11 <compatibility>vc14 ; to configure the clang that ships with VC14 I see: compile-c-c++ ..\..\..\bin.v2\libs\smart_ptr\test\shared_ptr_basic_test.test\clang-vc14-win-3.7\debug\shared_ptr_basic_test.obj clang.exe: error: no such file or directory: '/Od' clang.exe: error: no such file or directory: '/Ob0' clang.exe: error: no such file or directory: '/W3' clang.exe: error: no such file or directory: '/GR' clang.exe: error: no such file or directory: '/MDd' clang.exe: error: no such file or directory: '/Zc:forScope' clang.exe: error: no such file or directory: '/Zc:wchar_t' clang.exe: error: no such file or directory: '/wd4675' clang.exe: error: no such file or directory: '/EHs' Same errors with the llvm clang-3.9. On the other hand if I initialize with: using clang : : "C:/Progra~2/LLVM/bin/clang.exe" : <cxxflags>-std=c++14 <compatibility>vc14 <cxxflags>-fms-compatibility-version=19.00.22609 ; Then this sort of works for llvm clang, but not the msvc one (can't find c2.exe), but the compiler is identified as "clang-linux" and I see: LINK : warning LNK4044: unrecognized option '/-start-group'; ignored LINK : warning LNK4044: unrecognized option '/Bstatic'; ignored LINK : warning LNK4044: unrecognized option '/Bdynamic'; ignored LINK : warning LNK4044: unrecognized option '/-end-group'; ignored Plus some linker errors such as: yield_k_test.obj : error LNK2019: unresolved external symbol __mm_pause referenced in function "void __cdecl boost::detail::yield(unsigned int)" (?yield@detail@boost@@YAXI@Z) Ideas? Thanks, John.

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Boost 1.61.0 open for fixes
by Vladimir Prus 02 Apr '16

02 Apr '16

The master branch is now open for bugfixes for 1.61.0. Please make sure that develop tests are healthy prior to merging. We're two weeks late relative to the plan, so further dates were also moved by two weeks in the calendar. -- The release managers

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[Trac][convert] Associate Vladimir as author of Boost.Convert
by Vicente J. Botet Escriba 01 Apr '16

01 Apr '16

Hi, I requested sometime ago to add convert to the Trac system. It was done, but it was associated to me as maintainer. Please, could someone assign it to Vladimir Batov Vladimir, I guess you need to give your use in name. Best, Vicente Convert <http://www.boost.org/doc/libs/1_60_0/libs/convert/> An extendible and configurable type-conversion framework. Author(s) Vladimir Batov First Release 1.59.0

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Coroutine2 examples - Cannot link properly.
by Carlos Ferreira 01 Apr '16

01 Apr '16

Hello to all. I'm having trouble in compiling the coroutine2 examples. For the fibonacci example, the following linking error occurs: /usr/include/boost/coroutine2/detail/pull_control_block.ipp:62: undefined reference to `boost::context::execution_context::current()' Now, I know that I have to link against boost context, something that I'm already doing, but for some reason, it is not enough. Can anyone help me with this? Thank you. -- Carlos Miguel Ferreira Researcher at Telecommunications Institute Aveiro - Portugal Work E-mail - cmf(a)av.it.pt Skype & GTalk -> carlosmf.pt(a)gmail.com LinkedIn -> http://www.linkedin.com/in/carlosmferreira

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[boost 1.61] authorization to merge to master
by Raffi Enficiaud 31 Mar '16

31 Mar '16

Dear Boost, I would like to merge a boost.test bugfix to master. Those changes are running on develop for a week. I haven't done my PR for the website change log update because of that (would change the content of the PR). According to the schedule, boost 1.61 is open for bugfixes since 10 days now, but as I understood, we are still waiting for post RC2 go. - do I still have time for the website PR? - would the opening 1.61 for bugfixes be announced on the ML? - Am I allowed to merge those changes, so that I can reopen develop for post 1.61 developments? Thanks, Raffi Enficiaud

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[boost 1.61 - [thread] Request for permission to merge
by Vicente J. Botet Escriba 31 Mar '16

31 Mar '16

Hi, I would like to merge once it is announced that the release branch is open for fixes a minor fix https://svn.boost.org/trac/boost/ticket/11562 - (condition_variable_any::wait_until + recursive_mutex + steady_clock) timer expires after computer time is set forward on Ubuntu 64-bit add missing template parameter in wait_until. https://github.com/boostorg/thread/commit/9db70b803d8f45632cd92cd61ab019c1f… and the rollback of something that resulted in a regression https://svn.boost.org/trac/boost/ticket/12049 - Assertion failure from detached threads during shutdown rollback BOOST_THREAD_PATCH. https://github.com/boostorg/thread/commit/47357de276fe4fc01469f34c1dbf8b26f… Best, Vicente

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Re: [boost] [filesystem] Horrible documentation
by Tatsuyuki Ishi 31 Mar '16

31 Mar '16

> From: Edward Diener <eldiener(a)tropicsoft.com> > Date: Wed, 30 Mar 2016 00:06:00 -0400 > Subject: Re: [boost] [filesystem] Horrible documentation > > What sort of documentation unification with other libraries do you mean ? By saying unification, I'm talking about the green-background header. It's in most documentation and also on the homepage. > Can you not increase the font size, if it is too small for you to read, in your preferred browser since the doc is HTML ? The layout is quite problematic. Not only the font, text breaks border, and the page is too tall(long). I noticed it's created with FrontPage 2002. Come on, this is 2016.

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[release] Download data
by Daniel James 31 Mar '16

31 Mar '16

Hi, Currently the download details for a release are included in the quickbook source file for the release notes, which is a bit wonky, and makes it tricky to add extra data, so I'm thinking about storing it separately. This should make it easier to add things like hash signatures and links to third party downloads, such as the windows binaries. So I'm thinking about how to make it easy for people to add the details of their downloads. Could possibly create an extra file for each release, and then people can add data using pull requests, much as we've been using pull requests on the quickbook files, which seems to work fairly well. Another possibility is that we could pull in the details from the server's API, although I don't really fancy having to support multiple data sources with different APIs. Any other ideas? Also, is there any way in which you'd like me to make this kinds of information available for your scripts, packaging etc. Here's a rough version of how the internal data might be stored in a JSON file (other file formats are possible): { 'version': '1.61.0', 'status': 'beta', 'release-notes': '/feed/history/boost_1_61_0.qbk', 'documentation': '/doc/libs/1_61_0/', 'downloads': [ { 'url': 'http://..../boost_1_61_0_beta1.tar.bz2', 'hash': '484c635.....' }, { 'url': 'http://..../boost_1_61_0_beta1.7z', 'hash': 'f93de8.....' }, // ... ], 'third-party': [ { 'url': 'http://...', 'title': 'Windows binaries', 'whatever_else': '' } ] }

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[filesystem] Horrible documentation
by Tatsuyuki Ishi 30 Mar '16

30 Mar '16

Sorry for complaining. Is there any plan to use any documentation tool to regenerate this? It's not unified with other libraries, and too horrible due to the small font size. I really can't read that.

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