June 2014 - Boost - lists.preview.boost.org

[wave] preprocess fails using b2
by Fletcher, John P 28 Jul '14

28 Jul '14

I have been using b2 to build the preprocessed files for boost phoenix. When I try to do this it now fails with a failure to build thread.cpp "g++-4.6" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -pedantic -pthread -Wextra -Wno-long-long -Wno-variadic-macros -Wunused-function -pedantic -DBOOST_ALL_NO_LIB=1 -DBOOST_SYSTEM_STATIC_LINK=1 -DBOOST_THREAD_BUILD_LIB=1 -DBOOST_THREAD_DONT_USE_CHRONO -DBOOST_THREAD_POSIX -DBOOST_WAVE_SUPPORT_THREADING=0 -DNDEBUG -I"../../.." -c -o "../../../bin.v2/libs/thread/build/gcc-4.6/release/link-static/threading-multi/wavetool-on/pthread/thread.o" "../../../libs/thread/src/pthread/thread.cpp" ../../../boost/ref.hpp:32:25: error: redefinition of â€˜class boost::reference_wrapper<T>â€™ ../../../boost/core/ref.hpp:59:25: error: previous definition of â€˜class boost::reference_wrapper<T>â€™ ../../../boost/ref.hpp:56:75: error: redefinition of â€˜template<class T> const boost::reference_wrapper<T> boost::ref(T&)â€™ ../../../boost/core/ref.hpp:131:74: error: â€˜template<class T> const boost::reference_wrapper<T> boost::ref(T&)â€™ previously declared here . It looks as though it is picking up two copies of the header file ref.hpp. This is the case with both gcc 4.6 and also gcc 4.9.0 It is not clear to me where the source file is coming from. At the moment all the libraries in my modular boost are checked out as develop. This is meaning that I cannot update my preprocessed files. Please advise me what to do. Thanks John

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C++ committee meeting report
by Beman Dawes 25 Jul '14

25 Jul '14

The C++ committee met last week in Rapperswil, Switzerland. Actions that might be of interest to Boosters include: * Shipped the File System TS for ISO DTS (i.e. final) ballot. Since it would be very unusual for at DTS ballot to fail, the File System TS is essentially done. The committee is now actively looking for File System TS 2 proposals. My work now shifts to bringing the Boost implementation into compliance. * Shipped the Library Fundamentals TS for ISO PDTS (i.e. preliminary) ballot. This TS includes Boost.Any and Boost.Optional. * Voted to start work Library Fundamentals TS 2. The plan is to issue a continuing stream of Library Fundamentals TSes, with work starting on the next TS as soon as content for the current TS freezes. Hopefully Boost developers will submit proposals for this TS too. It will be a good home for small libraries that don't need a whole TS of their own. * Shipped the C++ Extensions for Parallelism TS for ISO PDTS (i.e. preliminary) ballot. * The Library Evolution Working Group (LEWG) voted to base the Networking TS on Boost.ASIO. That was a major surprise, as a Networking Study Group had been trying to build up a Networking TS from many small proposals. But in LEWG polls, support for ASIO was overwhelming, with no one at all voting against. This was a major vote of confidence for Boost.ASIO and Chris Kohlhoff. And several ASIO supporters were not even in the room at the time because Filesystem issues were being worked on elsewhere. The next C++ committee meeting is November 3rd to 8th in Urbana-Champaign, IL, USA. As always, Boosters welcome. --Beman

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[function_types] synthesis & explicit calling convention
by Domagoj Saric 25 Jul '14

25 Jul '14

I am unable to synthesize a pointer to a function (or a function type) with the fastcall (or any other, explicitly specified) calling convention. MSVC10 SP1: ** #define BOOST_FT_COMMON_X86_CCs #include "boost/function_types/function_pointer.hpp" #include "boost/function_types/property_tags.hpp" causes error C1017: invalid integer constant expression boost\boost_1_55_0\boost\function_types\detail\pp_cc_loop\preprocessed.hpp 28 ** doing #define BOOST_FT_COMMON_X86_CCs 1 (contrary to documentation but suggested in some places) and including #include <boost/function_types/config/config.hpp> fixes the above compiler error but then the actual typedef typename boost::function_types::function_pointer < MyParameterTypeList, boost::function_types::tag<boost::function_types::non_variadic, boost::function_types::fast_cc> >::type MyFunctionPointerType; fails with error C2065: 'fast_cc' : undeclared identifier help..please? :) -- Domagoj Saric Software Architect www.LittleEndian.com

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[winrt support] Adding support for Windows 8 store/phone to Boost libraries
by stgates 22 Jul '14

22 Jul '14

Hi, I work for Microsoft and we’ve been taking a look at making a some of the libraries in Boost work in the Windows 8 store and phone 8 runtime environment (WinRT). The main issue is use of Win32 desktop APIs that are banned in WinRT. The fixes generally involve updating to a newer non-banned version, like CreateEvent to CreateEventEx, or replace areas that call banned APIs using ifdef macro techniques. Similar to what already exists in some places of Boost when targeting different platforms or operating system versions. Files which do not use any banned APIs are largely unaffected. So far we’ve made the thread, chrono, system, and date_time libraries work in WinRT. To facilitate building and testing, changes are also required to the build and test libraries. Listed at the end of this message is a summary of the major changes made. I’m unfamiliar with the process for contributing back to Boost and would like to know what is the best way to work, to contributing back these changes to each of the individual libraries? I see the documentation for working with the git submodules (https://svn.boost.org/trac/boost/wiki/StartModPatchAndPullReq) Right now the changes for each library are in a forked repository on a new branch called ‘winrt’ from the ‘develop’ branch. For example the changes we've made for the chrono library can be located here: https://github.com/MSOpenTech/chrono/tree/winrt. Is the best way to proceed, or should I to just initiate a pull request to the develop branch on each of the individual libraries? Thanks, Steve Boost Build To support deciding which Windows API to target I added a new feature <windows-api> with values desktop, store, and phone. When utilizing the Visual Studio 2012 on Windows 8 or later the store and phone options are available, otherwise desktop is the default. Most of the changes in msvc.jam are to deal with selecting the correct vcvars setup script since with phone it is in a different location. I also added ARM support to the msvc toolset. For libraries which support the new Windows Runtime they now produce both the desktop and store binaries by default. This is done by calling the supported-windows-api rule I added in toolset.msvc which is called in the default-build section of each library’s Jamfile to indicate if targeting WinRT is supported. When building for the Windows 8 store or phone a new macro is now defined BOOST_WINAPI_FAMILY, set with the same value as WINAPI_FAMILY. This is then used in the individual Boost libraries to detect if targeting the new Windows Runtime and avoid certain banned APIs. To handle running tests against WinRT in an automated fashion that integrates well into the Boost workflow of running tests as part of the build, if windows-api is set to store, the test and all its binary dependencies need to have the APPCONTAINER requirement stripped. This then allows execution outside of the sandboxed Windows store environment. To do this all dependent dlls are copied into the tests executable’s folder, if using <link>shared. This is necessary to avoid modifying the APPCONTAINER flag on the actual product binaries. Just let me know if this needs more explanation, I’ll be glad to go into more detail if necessary. With this change the tests for Windows store run just like the existing Windows tests. I also added a new feature to control whether or not test binaries are actually executed, disable-test-execution. This is used to avoid running the ARM tests when building since Visual Studio 2012 doesn’t install on ARM devices. All these changes are in testing.msvc. Chrono The GetProcessTimes and GetThreadTimes functions doesn’t exist for WinRT and there are no replacements so the thread_clock and process user, system, and cpu clock features are disabled. Only process_real_cpu_clock is supported. Thread For the thread library most of the changes are around the fact that there is no way to directly create a thread in WinRT. To work around this I implemented the boost::thread class itself on top of std::thread. This actually leads to pretty clean code, much cleaner than directly targeting the WRL thread pool like in the C runtime. Other changes include moving from TLS to FLS and basic banned API replacements like WaitForSingleObjectEx for WaitForSingleObject. In general where it makes sense updates were made to utilize new APIs on platforms when available. Test For the Boost test library I added a new macro for turning on/off debugging support (BOOST_TEST_HAS_DEBUG_SUPPORT). WinRT doesn’t support creating processes so attaching a debugger to execution like this is disabled. There also are no APIs for accessing registry keys, so this feature has been disabled as well. -- View this message in context: http://boost.2283326.n4.nabble.com/winrt-support-Adding-support-for-Windows… Sent from the Boost - Dev mailing list archive at Nabble.com.

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Proposal: Vector-like container, which takes O(log(N)) for insert/erase, feedback
by Alexander Kuprijanov 12 Jul '14

12 Jul '14

Hi, everybody! The most important feature of my container is performance. However, other features will appear later. https://github.com/alexkupri/array/blob/master/description/description.txt Today I compared my container with rope. My container outperformed it 10 times. > Date: Thu, 3 Apr 2014 16:39:29 -0700 > From: Glen Fernandes <glen.fernandes(a)gmail.com> > I wasn't sure at first why my name was in parenthesis in the e-mail > subject. :-) > Glen It's my fault, sorry about it. > Date: Fri, 04 Apr 2014 13:41:04 +0200 > From: Adam Wulkiewicz <adam.wulkiewicz(a)gmail.com> > Subject: Re: [boost] Proposal: Vector-like container, which takes > O(log(N)) for insert/erase > AFAIU just like a B-tree can be seen as a generalization of a binary > search tree in that a node can have more than two children, your > container can be seen as a similar generalization of a Rope. Or it can > be seen as an augumented B-tree (not really because the values are no > longer stored in internal nodes and the tree isn't sorted, correct me > if I'm wrong). Your You understood right. > proposal is very similar to Counted B-tree > (http://www.chiark.greenend.org.uk/~sgtatham/algorithms/cbtree.html) > which is a B-tree with random access. The difference is that your > container can't be used to search for a stored value in O(logN) > without sorting and binary search. This may be ok if someone require > only random access, the size of a node is smaller which probably > improves the cacheing. Again, right. There are a lot of situations when only random access is necessary. You probably will not sort characters in string. > > In general, B-tree was introduced to improve the performance of the > access to data stored in persistent memory (lower performance). In > this case it was better to load the whole page into memory (and cache > it) than load many small, scatered parts. But in the case of > RAM-only-access, a binary search tree should be faster. As far as we > don't consider spatial indexing, interval trees, etc. where > values/nodes may "overlap" somehow and we must search in more than one > subtree. Therefore I'm wondering if a classic Rope would be faster > than your container in the use-case you're testing - simple insert and > random It outperformed Rope 10 times. It's expected result. Please visit my link, I added verbose explanation under "ROPE TEST" section. Shortly speaking, four reasons exist: cache, pages, balancing and malloc/free. > access to a in-memory container. Have you test it? I'd perform 2 tests: > 1. Very big number of values + truly random insert/access to prevent > cacheing > 2. insert/access in the same area I've tested with truly random tests. Please see results and code of SingleOperationPerformanceCheck and MultipleOperationsTest functions. Tell me, if I'm wrong. > > IMHO the benefits related to the use of this container should be more > noticable if the persistent storage were used. In memory/cache there are the same relationship as in HD/memory. > > As for the name, it's definietly not an array. I'd call it B-rope. Thanks, your option is accepted. I'll collect more options and we'll vote. I like brope. > > Regards, > Adam > Message: 9 From: Lars Viklund <zao(a)acc.umu.se> > Date: Fri, 4 Apr 2014 14:10:06 +0200 > If it doesn't have contiguous storage, it's not a replacement for > vector, however much you want it to be the universal container that > everyone uses for everything. > It may be a better general-purpose container compared to the > usual default containers, deque and vector, but it isn't a replacement > for either of them. Well, I would see it as first choise container for non-sorted data. It's comparable with vector/deque on small arrays and outperforms them on large sizes. It's more preferrable than list at least in terms of malloc/free calls. And it's probably better for strings. So one should use it by default in all cases with unsorted data and use list, vector, deque and string only if he/she really understands what he/she does. > You use the term 'intrusive' in the documentation, but it doesn't seem > to carry the usual meaning that it requires the types involved to > participate in the container structure. You are right. I've corrected the documentation. Now I call "fat leaves" leaves which contain elements, and "thin leaves" leaves which contain pointers to elements. > Your tests doesn't seem to exercise much else than container<int> > either. Suggest your tests. > I'm not quite sure I like the explicit L/M non-type template parameters > either, considering that it leaks implementation detail into every > single user of the type. Well, you are right in principle. It must have default parameters. But it's platform dependent, they should be chosen so that branch and leaf would take roughly 1 cache line, minus information required for malloc overhead. > As for the Copy-on-Write semantics, isn't the general consensus that CoW > is a horrible horrible thing and is very hard to get right+fast in the > modern world with concurrency? I disagree with your estimation. There are different situations, different machines. Embedded and mobile machines want to save memory. Large machines can also want to save memory, if they amount of data is large. Finally, they can even speed-up by avoiding copying the whole array. Imagine you are writing text editor. (DNA editor, sound editor, etc.) You make backup copy and continue editing, again backup copy and continue editing. And you keep only forward commands (without undo). You can easily rollback to any state you need. Ofcourse, user should decide, whether CoW option is necessary for him/her, because it wastes resources when enabled and not used. > > Message: 11 > Date: Fri, 4 Apr 2014 23:23:09 +1000 > From: Vadim Stadnik <vadimstdk(a)gmail.com> > Could you please provide a figure that shows data association with > nodes in > your data structure? I updated the doc, follow the link above.

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Help with understanding regression test results
by Andrzej Krzemienski 01 Jul '14

01 Jul '14

Hi, Recently I observed lots of test cases showing as failed in regression tests on branch 'develop' in Boost.Optional: http://www.boost.org/development/tests/develop/developer/optional.html When I try to inspect the results they are either empty or refer to the places in the code that do not exist anymore in branch 'develop', as though the test environments were using partial results of GIT commits. But the test dates are after the last commit, so it looks like something is broken with the testing framework. Anyone can help me with figuring out what to do? Regards, &rzej

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[fusion] Definition for FUSION_MAX_MAP_SIZE
by Edward Diener 01 Jul '14

01 Jul '14

The documentation for fusion implies that FUSION_MAX_MAP_SIZE is defined whenever a fusion header is included. is this so ? Testing this out under Wave suggests it is not so. What fusion header needs to be included in order to bring in the definition for FUSION_MAX_MAP_SIZE ?

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[utility] prior(it, n) for n being an unsigned type
by Adam Romanek 30 Jun '14

30 Jun '14

Hi! This is a re-post from boost-users mailing list, as I didn't get any response there. I've just finished investigating an issue in my code which led it to an assert/abort in certain cases. It turned out it was caused by the use of boost::prior(it, n) where n was unsigned int with some non-zero value. I found a question [1] on the mailing list back in 2004 which describes this issue. Additionally a solution to this problem was also posted in one of the replies [2]. My question is - why hasn't it made into the repository yet? The current behavior of boost::prior(it, n) when n is unsigned type is far from the one expected by its potential users so I think it should either be properly documented (warned) or fixed immediately. Am I not seeing something? WBR, Adam Romanek [1] http://lists.boost.org/Archives/boost/2004/02/61556.php [2] http://lists.boost.org/Archives/boost/2004/02/61578.php

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[utility][iterator] generator_iterator tests and documentation.
by Daniel James 30 Jun '14

30 Jun '14

Hi, The generator_iterator tests and documentation are in both the utility and iterator modules. There are also some relevant issues in the inspect report for the iterator module: http://boost.cowic.de/rc/docs-inspect-develop.html#iterator

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[iterator] Make operators conditionally defined
by Andrey Semashev 30 Jun '14

30 Jun '14

Hi, I've made this pull request: https://github.com/boostorg/iterator/pull/4 which makes operators defined for iterator_facade conditionally defined depending on the iterator category. As a side effect this change fixes Boost.Graph tests broken by the recent change to boost::next()/prior() [1]. Could someone take a look and merge it? [1] http://lists.boost.org/Archives/boost/2014/06/214788.php

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