June 2014 - Boost - lists.boost.org

A GUI Library
by jinhao 09 Nov '17

09 Nov '17

Hi, all I am developing a GUI library, it takes aim at easy-to-use and portable library for modern C++ methods. The project at http://stdex.sourceforge.net A git repository at http://nanapro.codeplex.com A brief at http://nanaproject.wordpress.com/2011/12/16/preliminary-study-of-nana-c-lib… Is there any interest in this library? Regards Jinhao

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bad include guards
by Steven Watanabe 26 Jan '17

26 Jan '17

AMDG The following pairs of files have identical include guards ./boost/concept_check/general.hpp ./boost/concept/detail/msvc.hpp ./boost/concept_check/msvc.hpp ./boost/concept/detail/msvc.hpp ./boost/filesystem/cerrno.hpp ./boost/cerrno.hpp ./boost/interprocess/containers/tree.hpp ./boost/interprocess/containers/detail/tree.hpp ./boost/mpl/min_max.hpp ./boost/mpl/max.hpp ./boost/mpl/vector/aux_/front.hpp ./boost/mpl/list/aux_/front.hpp ./boost/multi_index/identity_fwd.hpp ./boost/multi_index/identity.hpp ./boost/python/pointee.hpp ./boost/python/detail/pointee.hpp ./boost/spirit/phoenix/closures.hpp ./boost/lambda/closures.hpp ./boost/xpressive/proto/v1_/proto_typeof.hpp ./boost/xpressive/proto/proto_typeof.hpp ./libs/config/test/boost_no_dep_nested_class.ipp ./libs/config/test/boost_has_vc6_mem_templ.ipp ./libs/config/test/boost_no_mem_templates.ipp ./libs/config/test/boost_has_vc6_mem_templ.ipp ./libs/config/test/boost_no_std_allocator.ipp ./libs/config/test/boost_has_vc6_mem_templ.ipp ./libs/conversion/test.hpp ./libs/any/test.hpp ./libs/interprocess/example/print_container.hpp ./libs/interprocess/example/printcontainer.hpp ./libs/interprocess/test/expand_bwd_test_template.hpp ./libs/interprocess/test/allocation_test_template.hpp ./libs/interprocess/test/printcontainer.hpp ./libs/interprocess/example/printcontainer.hpp ./libs/interprocess/test/print_container.hpp ./libs/interprocess/example/printcontainer.hpp ./libs/iostreams/test/detail/utf8_codecvt_facet.hpp ./boost/detail/utf8_codecvt_facet.hpp ./libs/regex/test/regress/test_regex_search.hpp ./libs/regex/test/regress/test_partial_match.hpp ./libs/serialization/test/C.hpp ./libs/serialization/test/A.hpp ./libs/xpressive/perf/regex_comparison.hpp ./libs/regex/performance/regex_comparison.hpp ./tools/inspect/time_string.hpp ./tools/common/time_string.hpp In Christ, Steven Watanabe

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

12 Aug '15

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

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Arguing about names in Boost libraries
by Edward Diener 06 May '15

06 May '15

What is wrong with the people commenting on libraries for Boost who are so concerned about the names being used ? We are talking only about C++ identifiers and yet there are now endless discussions where people disagree on names or argue that some name is not what they want or that they like some other name, with a list of names that they find adequate. This is irrelevant. There is something mentally wrong about all those peoples spending endless amounts of time around this issue. I notice this does not happen nowadays for just one library but for ever single library, or proposed library, which is mentioned on this mailing list. Is this the way all of you people actually work in your daily jobs, or on your own projects, spending hours and days arguing with others about C++ identifiers for every little thing ? Are you not aware of the absurdity of your endless remarks ? Grow up ! Surely there are better things to do than carry on endlessly about some name, that is should be x or y or z or some other inane preferable list. It's time for somebody to say this, so I will do it. A C++ identifier name, as long as it is vaguely about what the functionality entails, is perfectly adequate. It does not have to satisfy everyone in the universe. Period !

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Interactive metaprogramming shells
by Abel Sinkovics 28 Dec '14

28 Dec '14

Hi, I've built interactive shells for preprocessor and template metaprogramming. I've been using them for development and debugging of metaprograms and I think Boost developers could also find them useful. You can type in (metaprogramming) expressions which get evaluated and the result is displayed immediately. For example you can type boost::mpl::push_front<boost::mpl::vector<int, char>, double>::type and you get boost_::mpl::vector<double, int, char> as the result (the boost_ namespace is used because there are some tricks there to make the output more readable). As an example for the preprocessor shell you can type BOOST_PP_REPEAT(3, foo BOOST_PP_TUPLE_EAT(3), ~) and you get foo foo foo as the result. The tools are based on the Boost.Wave library and Clang. You can get them here: Preshell for preprocessor: https://github.com/sabel83/preshell Metashell for template metaprograms: https://github.com/sabel83/metashell You can also try them from your browser here: http://abel.web.elte.hu/shell Feedback is welcome. Regards, Ábel

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IDE for developing Boost
by Jens Müller 20 Dec '14

20 Dec '14

Hi, I am looking for recommendations for developing Boost, especially code in the graph library. At work, most developers (not for Boost, for some commercial software), most developers are using Eclipse. This works quite fine as soon as it has properly auto-discovered include paths etc. But before fiddling around with Eclipse to get all the settings right, I'd wanted to to ask for your recommendations. And maybe there are already settings available to make it "just work", at least initially. Cheers, Jens

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[coroutine] x86 msvc11 stack corruption
by Tobias Loew 12 Dec '14

12 Dec '14

Hi, I use Boost 1.55 uni-directional coroutines to build an x86 MSVC11 application. I have a simple pull-type (boost::coroutines::coroutine<void>::pull_type) that under certain reproducable conditions destroys the stack after returning from the coroutine. Here is the corrupted stack as shown by VS2012 > ebs2000.exe!CScriptMainFrame::DoRun(CPascalEditorDoc * 0x00000000, int 0x00000000, int 0x00000000) Line 3372 C++ ebs2000.exe!CScriptMainFrame::OnDebugStepover() Line 4916 C++ mfc110u.dll!_AfxDispatchCmdMsg(CCmdTarget *, unsigned int, int, void (void) *, void *, unsigned int, AFX_CMDHANDLERINFO *) C++ 00000002() Unknown [Frames below may be incorrect and/or missing] mfc110u.dll!CCmdTarget::OnCmdMsg(unsigned int, int 0x00000000, void *, AFX_CMDHANDLERINFO *) Line 364 C++ mfc110u.dll!CWnd::OnCommand(unsigned int 0x00018263, long 0x00000000) Line 2785 C++ mfc110u.dll!CFrameWnd::OnCommand(unsigned int 0x00018263, long 0x00000000) Line 389 C++ ... This only happens in windows x86 32-bit release-builds when the coroutine finishes upon a user-action that also includes a windows WM_SETFOCUS message on my menu-bar. If at least one of the following is true, the stack-corruption does NOT happen: - debug-build - x64 build - using a different pull-type, e.g. enum status_enum{...}; boost::coroutines::coroutine<status_enum>::pull_type - not returning form the coroutine, but pushing just before the end of the coroutine and swapping the pull-type-variable with a default constructed "not-a-coroutine" Even though I have a lot of workarounds, I still would like to know, why this happens. regards Tobias PS: I had to recompile ml /safeseh /c make_i386_ms_pe_masm.asm ml /safeseh /c jump_i386_ms_pe_masm.asm to get SAFESEH-libraries. -- View this message in context: http://boost.2283326.n4.nabble.com/coroutine-x86-msvc11-stack-corruption-tp… Sent from the Boost - Dev mailing list archive at Nabble.com.

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[modularization] LocalFunction and ScopedExit cycle
by Vicente J. Botet Escriba 06 Oct '14

06 Oct '14

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[units] Pull request and RFC: information unit definitions for Boost.Units
by Erik Erlandson 20 Aug '14

20 Aug '14

Link to PR: https://github.com/boostorg/units/pull/3 Description: Adds unit definitions for standard units of information: bit, byte, nat, hartley, shannon. Defines a new unit system boost::units::information for convenient manipulation. Also includes IEC binary prefixes: kibi, mebi, gibi, tebi, pebi, exbi Example code: https://github.com/erikerlandson/units/blob/info_units/example/information.… Unit testing code: https://github.com/erikerlandson/units/blob/info_units/test/test_informatio…

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[testing] Proposal - regression tests results display upgrade
by Adam Wulkiewicz 17 Aug '14

17 Aug '14

Hi, Currently test failures of a new feature are always marked with the yellow color and a word 'fail'. Would it make sense to use some more descriptive color/naming scheme? In particular it would be nice to distinguish between the actual failures and the situations when the compilation of a test took too much time or an output file was too big. Would it make sense to also distinguish between compilation, linking and run failure? E.g. instead of a simple 'fail' use 'fail (c)', 'fail (l)' and 'fail (r)'. E.g. the color for actual failures could be orange and for "others" could stay yellow. Furthermore, currently it's impossible to see the results of compilation if a test passed. Would it make sense to change it? This would allow us to view and fix warnings even if the test was passed. The test passed with warnings could be marked e.g. with 'pass (w)' or the color could be set to some between yellow and this light green. If you directed me where it should be done I could try to change it. I'm guessing it would require modifying some script generating the page and some CSS? Regards, Adam

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[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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[fusion] BOOST_FUSION_ADAPT_TPL_STRUCT
by Greg Rubino 29 Jun '14

29 Jun '14

Hello all, I'm trying to do something like this with fusion: struct exists_tag {}; template <typename A> struct unary { type_a m_name; }; template <> struct unary<exists_tag> { type_b m_name; }; BOOST_FUSION_ADAPT_TPL_STRUCT((A), (unary)(A), (type_a)(m_name)); BOOST_FUSION_ADAPT_TPL_STRUCT((), (unary)(exists_tag), (type_b)(m_name)); I'm not sure if I'm way off here, or if there is some way to accomplish this that I'm just not seeing. Here's the error that I get when I try to compile this code: ./include/query_tree.h:122:1: error: template parameters not used in partial specialization: ./include/query_tree.h:122:1: error: ‘Oper’ Repeated 8 times. Any ideas? Thanks, Greg

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function convert() -- do you find it useful?
by Andrzej Krzemienski 29 Jun '14

29 Jun '14

Hi, This is the second time that I have found the following function useful when playing with variants of Optional library: template <typename T, typename U> typename std::enable_if<std::is_convertible<U, T>::value, T>::type convert(U && u) { return std::forward<U>(u); } It performs an implicit conversion from U to T, but you can call it explicitly. [1st] time I needed it to implement the behavior of value_or (described in http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2013/n3672.html#optional… ): template <class U> constexpr T optional<T>::value_or(U&& v) const&; Requires: is_copy_constructible<T>::value is true and is_convertible<U&&, T>::value is true. Returns: bool(*this) ? **this : static_cast<T>(std::forward<U>(v)). This needs to be implemented in one expression in C++11, because the function is constexpr, so in the ternary operator, I could either apply no cast and risk unnecessary ambiguity in result type in certain cases, or use a static_cast and bring the explicit conversions in that I didn't want. Function convert() saved the day. [2nd] time was when trying to disable the overload in C++11 using SFINAE, but I didn't want to use enable_if (see a more complete example here: http://akrzemi1.wordpress.com/examples/overloading-enable_if-3/) template <typename U> auto value_or(U const& v) const -> decltype(convert<T>(v)) { if (*this) return this->value(); else return v; } template <typename F> auto value_or(F const& f) const -> decltype(convert<T>(f())) { if (*this) return this->value(); else return f(); } I wanted to check with Boost developers if you find such function convert generally useful (and worth adding somewhere in Boost), or is it just my specific needs. Regards, &rzej

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[regex] [test] Regex auto-link-test problem
by Marcel Raad 29 Jun '14

29 Jun '14

Hi, I'm trying to set up all regression tests on my Windows machine. When I try to execute the test in regex\test\auto-link-test, I get the following error message: ..\..\..\..\b2.exe Jamfile:38: in modules.load ERROR: rule "subproject" unknown in module "Jamfile<[...]\auto-link-test>". [...]/tools/build/src/build\project.jam:311: in load-jamfile [...]/tools/build/src/build\project.jam:64: in load [...]/tools/build/src/build\project.jam:145: in project.find [...]/tools/build/src\build-system.jam:535: in load [...]\tools\build\src/kernel\modules.jam:289: in import [...]\tools\build\src/kernel/bootstrap.jam:139: in boost-build [...]\boost-build.jam:17: in module scope I noticed that the build file is called Jamfile instead of Jamfile.v2, do I have to set Boost.Build to some v1 mode?

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Regression tests broken?
by John Maddock 29 Jun '14

29 Jun '14

For reasons I can't understand, large numbers (almost all actually) of the Math lib tests have just started failing on both master and develop, the error messages all relate to missing object files, for example from a PCH build like this: http://www.boost.org/development/tests/master/developer/output/teeks99-02j-… LINK : fatal error LNK1181: cannot open input file 'C:\local\teeks99-02\j\results\boost\bin.v2\libs\math\test\msvc-12.0\debug\asynch-exceptions-on\link-static\threading-multi\pch_light.obj' Or from common object files that are built with an "obj" rule: http://www.boost.org/development/tests/master/developer/teeks99-02j-win2008… LINK : fatal error LNK1181: cannot open input file 'C:\local\teeks99-02\j\results\boost\bin.v2\libs\math\test\msvc-12.0\debug\asynch-exceptions-on\link-static\threading-multi\compile_test_main.obj' I'm unable to reproduce locally (at least when building in libs/math/test), and strangely not all test runners are showing the issue - though most of them are. Anyone any ideas? Thanks, John.

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Re: [boost] Interest in bit-wise flags?
by Jeffrey Bush 28 Jun '14

28 Jun '14

> > > > > Hi Boost! > > > > I have developed a type-safe bit-wise flags class for my own personal use > > and > > am wondering if it would be of interest for me to submit it as a Boost > > library. > > At the moment it is not ready for submission (code is messy) but I am > > testing > > the waters so I present an overview below. > > * Fully ISO standard C++11 (except for an MSVC version which is > > API-compatible > > except it doesn't support as many an infinite number of flag names) > > * They are type-safe, requiring explicit casts to and from > integers/booleans > > * Supports standard bit-wise operations, and always keep values within > the > > possible set of flags > > * Supports getting the name of a flag and looking up flags by name at > > run-time > > (when a flag is actually multiple-flags it gives something like "A|B") > > * Supports getting an array of all flags at run-time > > > > Now the bad things, which may be a deal-breaker: > > * Because of limitations in C++ the syntax can feel a bit awkward. You > have > > to > > use a macro to define flag-names (which actually creates a class) then > you > > can pass those flag-names as template arguments to the flags. An > example: > > FLAG_NAME(A); > > FLAG_NAME(B); > > FLAG_NAME(C); > > typedef Flags<std::uint8_t, Flag_A, Flag_B, Flag_C>::WithValues<0x01, > > 0x02, 0x04> MyFlags; > > * I also couldn't get around using the ::WithValues nested class > > * I use a set of macros to make this cleaner (e.g. the above could be > > FLAGS(A, B, C)) and once defined there is no more ugliness > > > > Thanks for consideration! > > Jeff > > > > _______________________________________________ > > Unsubscribe & other changes: > http://lists.boost.org/mailman/listinfo.cgi/boost > > > > > > Jeffrey Bush <jeff <at> coderforlife.com> writes: > > I have posted the current (ugly) code online: > https://gist.github.com/coderforlife/6d8bac451d49dd1a0c81#file-flags-hpp > > Above that is the even uglier MSCV-specific implementation. > > I focused on function not readability when making it, I understand that it > would take significant work to make it Boost ready. > > Differences from BOOST_BITMASK or lordodinscpplib are that it supports ~ > that is value-constrained (only flips bits that are covered by flags, it > supports names at run-time (converting to and from strings), and it can > default-value then flags with powers of two. > > If those features are undesired, then this class is unnecessary seeing that > those other solutions are significantly simpler or more portable. > > However, looking at those has given me some ideas on how to simplify my > code > and make it possibly work in Clang. > > Jeff > I have updated it, simplifying the design while keeping the same API and provided a simple test program, both available at https://gist.github.com/coderforlife/6d8bac451d49dd1a0c81. It now works fine in all compilers I have tested (MSVC 2010, MSVC 2013, mingw-w64 4.8.2, gcc 4.8.2, clang 3.4). This simplification greatly reduced the amount of code and allowed me to combine the fallback version that doesn't need variadic templates into the main version. I have also made it so the declaration can be inside a class or shared header and the definition elsewhere. This separation was necessary because const non-integral values cannot be defined in classes. Additionally, I have cleaned up the code quite a bit to fit better with Boost standards, although not complete yet (still uses tabs and some lines are longer than 80 characters although most are not). The only difference in API is that you can no longer pre-declare flag name objects or do `typedef Flags<uint8_t, Name1, Name2, Name3>::WithValues<1,2,4> MyFlags` or similar like before, you must use the macro FLAGS()/FLAGS_WITH_VALUES() [which was available before]. I have compiled a very detailed list of differences between BOOST_BITMASK and (BOOST_)FLAGS. The first is an advantage of BITMASK, the second is a draw, and the remainder are advantages of FLAGS. - BITMASK requires an enum or scoped enum to be declared and then the macro to be used, but can entirely within a shared header. FLAGS would be a single-line, or if in a shared header have separate declarations and definitions. Both support being inside classes by having some macro outside the class. - BITMASK supports unlimited flags with less than 2^32 while FLAGS supports at most 32 flags but any underlying integral type. Both could have their limits increased. - BITMASK when used with scoped enums requires full bool casting and does not support the ! operator for checking if any/no flag is set and when used with original enums has some type safety issues (can compare values from different enums directly). FLAGS has the best of both, have strong type safety while also supporting the ! operator and an explicit bool cast (safe-bool). - BITMASK allows (and actually the ~ operator causes) bits that aren't associated with flags to be set while FLAGS prevents these bits from ever being set. This is a numerical safety (I have examples when this would be important). - FLAGS will automatically set the flag-values to powers of two if you want it to, reducing possibility of typos for simple flags while still allowing you to have explicit flag values when necessary (for example, when having pre-defined names for combinations of flags or retaining number-compatibility after dropping a particular flag name). BITMASK always requires you to set the values explicitly. - FLAGS support runtime value-name conversion, allowing something like XML reading/writing using the flag names instead of the numbers, debugging output, user-input parsing, etc. Additionally, BOOST_BITMASK is in boost/detail, does this mean it shouldn't be used outside of Boost? (I have a method of making it so there is no need for a separate declaration vs definition, however it is "ugly" but does work [and the end-user wouldn't have to really know] - it makes each flag-name a static function instead of static-const variable and adds an implicit constructor that takes such a static function and calls it to get the real value which is a static-const local variable). Jeff

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