March 2012 - Boost - lists.preview.boost.org

has_member_fnc?
by Neal Becker 17 Mar '12

17 Mar '12

It seems c++11 has a new way to spell enable_if, and this can be used to implement has_member_fnc, as in this example: http://pastebin.com/mH2cZ4NP I wonder if has_member_fnc would be a good addition to boost?

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[range] adaptors and member functions pointers
by Yanchenko Maxim 17 Mar '12

17 Mar '12

Hi, While transforming and filtering sequences, it's pretty common to call the elements' member functions, so I think it's worth adding some syntactic sugar for range adaptors in order to achieve cleaner syntax. E.g. if we have a class struct Foo { std::string description() const; }; and we want to get all non-empty descriptions, we could just write this clean code: foo_list | transformed(&Foo::description) | filtered(&std::string::size) To enable this syntax, the attached patch should be applied to boost/range/adaptor/argument_fwd.hpp (diff against 1.47.0). Is there any interest to add this to Boost.Range? Thanks, Maxim

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[thread] Jamfile issue
by Emil Dotchevski 16 Mar '12

16 Mar '12

Hello, In my own Jamfile targets, if I refer to Boost Thread as: alias thread : $(boost)//thread ; I get: error: No best alternative for boost_1_48_0/libs/thread/build/thread_sources next alternative: required properties: <threadapi>win32 <threading>multi not matched next alternative: required properties: <threadapi>pthread <threading>multi not matched I could do this instead: alias thread : $(boost)//thread/<threadapi>win32 ; But that clumsy, I'd be dispatching between POSIX and WIN32 configurations, which ideally should be done internally by Boost Thread's Jamfile. Is there a better way to refer to Boost Thread? Emil Dotchevski Reverge Studios, Inc. http://www.revergestudios.com/reblog/index.php?n=ReCode

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[trunk] what is MSVC 9.0 STL port 5.2?
by lcaminiti 16 Mar '12

16 Mar '12

Hello all, The trunk regressions tests: http://beta.boost.org/development/tests/trunk/developer/summary.html Run on MSVC 9.0 "STL port 5.2" and "WM5 STL port 5.2" on VeecoFTC: msvc- 9.0~stlport5.2 msvc- 9.0~wm5~stlport5.2 What are those? How are they different from the tests that run on MSVC 9.0 "msvc-9.0" on RW_WinXP_VC? Specifically, would you know if the following macro will be #defined to 1 on msvc- 9.0~stlport5.2 and msvc- 9.0~wm5~stlport5.2? // MSVC 7.1=1300, 8.0=1400, 9.0=1500, 10.0=1600 (this workaround was tested at // MSVC 8.0 but it might work also for all MVSC >= 7.1). #if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1400)) && \ !defined(BOOST_TYPEOF_EMULATION) /* doesn't work in typeof-emu mode */ # define BOOST_SCOPE_EXIT_AUX_TYPEOF_THIS_WORKAROUND_01 1 #else # define BOOST_SCOPE_EXIT_AUX_TYPEOF_THIS_WORKAROUND_01 0 #endif Thanks a lot. --Lorenzo -- View this message in context: http://boost.2283326.n4.nabble.com/boost-trunk-what-is-MSVC-9-0-STL-port-5-… Sent from the Boost - Dev mailing list archive at Nabble.com.

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[scope_exit] can MSVC lambdas capture data members?
by lcaminiti 16 Mar '12

16 Mar '12

Hello all, Can anyone try the following code on a MSVC compiler with lambdas (MSVC10?)? #include <vector> struct person {}; struct world { void add_person(person const& a_person) { bool commit = false; persons_.push_back(a_person); auto scope_exit = [&commit, &persons_]() mutable -> void { if(!commit) persons_.pop_back(); }; commit = true; scope_exit(); } private: std::vector<person> persons_; }; int main() { world w; person p; w.add_person(p); return 0; } This code compiles on GCC 4.5.3 with C++0x extensions (including lambdas) but based on some errors I'm seeing in trunk's ScopeExit regressions tests, I'm guessing it will fail using MSVC lambdas with errors similar to the followings: error C3480: 'world::persons_': a lambda capture variable must be from an enclosing function scope warning C4573: the usage of 'world::persons_' requires the compiler to capture 'this' but the current default capture mode does not allow it Unfortunately, I don't have a MSVC compiler with lambdas so thank you very much for trying my code! --Lorenzo -- View this message in context: http://boost.2283326.n4.nabble.com/boost-scope-exit-can-MSVC-lambdas-captur… Sent from the Boost - Dev mailing list archive at Nabble.com.

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[Range] Derived from iterator_range and operator==
by Olaf van der Spek 16 Mar '12

16 Mar '12

Hi, Shouldn't this just work? Comparing two boost::iterator_range<const char*> works fine. #include <boost/range/iterator_range.hpp> class str_ref : public boost::iterator_range<const char*> { }; int main() { boost::iterator_range<const char*> a; a == a; str_ref b; b == b; // 12 } is.cpp: In function ‘int main()’: is.cpp:12:7: error: ambiguous overload for ‘operator==’ in ‘b == b’ is.cpp:12:7: note: candidates are: is.cpp:12:7: note: operator==(boost::iterator_range<const char*>::unspecified_bool_type {aka const char* boost::iterator_range<const char*>::*}, boost::iterator_range<const char*>::unspecified_bool_type {aka const char* boost::iterator_range<const char*>::*}) <built-in> /usr/include/boost/range/iterator_range_core.hpp:438:21: note: bool boost::operator==(const boost::iterator_range<IteratorT>&, const ForwardRange&) [with IteratorT = const char*, ForwardRange = str_ref] /usr/include/boost/range/iterator_range_core.hpp:431:21: note: bool boost::operator==(const boost::iterator_range<IteratorT>&, const boost::iterator_range<Iterator2T>&) [with Iterator1T = const char*, Iterator2T = const char*] /usr/include/boost/range/iterator_range_core.hpp:387:21: note: bool boost::operator==(const ForwardRange&, const boost::iterator_range<IteratorT>&) [with IteratorT = const char*, ForwardRange = str_ref] -- Olaf

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[O/T git and workflows] A couple of questions
by Brian Schrom 16 Mar '12

16 Mar '12

This is slightly off topic, but with recent (and future ;) ) Git discussions, hopefully not too off topic... If Boost were to adopt Git, I believe Gitolite (https://github.com/sitaramc/gitolite, http://sitaramc.github.com/gitolite/ -- docs) or something similar would need to be used which provides some centralization features. Maybe github? Gerrit (http://code.google.com/p/gerrit/) is primarily a code review tool, though provides some centralized support. git flow (https://github.com/nvie/gitflow) has some nice wrappers for branch management. This looks especially appealing for gently introducing people to git. It provides structure and reduces the number of commands. My question is what the workflow, tools, and experience people have with combining all of these tools. I think this community will need something along these lines if it is to transition to Git anyway, so maybe this will get that part of the discussion started. ---- Just to keep the discussion on git going... In my "brain storming" world, there is the central boost repo (which currently exists), I clone it. (When can we start submitting to github? :) ) I use git flow locally for my own branch management. This allows me to work on multiple features independently. When a feature is completed locally, I send the patch (possibly via gerrit ) and that patch sits in the maintainers review queue. If accepted, the patch is applied and merged for the next release. Largely, I believe this is what exists right now. Admittedly, I've only ever submitted one patch to Boost. That was an email directly to the library author. What I want to understand is, if such tools were adopted, would it lower the burden on library maintainers enough to justify the change? Again, my perception of the way things currently are vs could be with git: centralized subversion server. centralized git server (gitolite?) svn checkout trunk git clone developer Use whatever local strategy for development use git flow + whatever local strategy for development create patch and attach to TRAC ticket git push to gerrit server (for instance) poke people on mailing list about patches (poke people on mailing list about pending reviews and such) maintainer applies patch and pushes to server An approved patch gets pushed to centralized server. * Where would build-bot/Jenkins interact in this process? It seems that there are a few places...1) Want to be able to test local branch during development, 2) then test during the patch review and approve process, and 3) finally test on the integrated branch. * Would the "better" localized development tools (git + git flow + more direct patch submission) facilitate more participation in the community over the current method? (my guess is not much, though the people that do contribute might appreciate the improvements. And some would consider them not improvements and stop contributing? * Would the review process save the maintainer's enough time and effort that they're more able to process more patches on a regular basis?

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[random] uniform_01 not usable in backwards compatible mode
by John Maddock 15 Mar '12

15 Mar '12

Apologies for the minor flood of posts.... uniform_01 has a default constructor only (fine for the "new" interface), but for the old interface, the base class has a single arg constructor only and no default constructor. In other words there's no way to construct a uniform_01 in backwards compatibility mode (when the first template arg is a distribution). Also the traits selection class that switches between new and old interfaces should probably be documented (and not in detail{ namespace). Cheers, John.

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[bind] Error C4430 in bind.hpp
by Robert Dailey 15 Mar '12

15 Mar '12

For some reason when I include <boost/bind.hpp> I get the following errors: 1>c:\code\work\cmake-mds\build-vc9\third_party\boost\1.48.0\include\boost\bind\bind.hpp(1200) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int 1>c:\code\work\cmake-mds\build-vc9\third_party\boost\1.48.0\include\boost\bind\bind.hpp(1201) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int 1>c:\code\work\cmake-mds\build-vc9\third_party\boost\1.48.0\include\boost\bind\bind.hpp(1203) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int 1>c:\code\work\cmake-mds\build-vc9\third_party\boost\1.48.0\include\boost\bind\bind.hpp(1204) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int 1>c:\code\work\cmake-mds\build-vc9\third_party\boost\1.48.0\include\boost\bind\bind.hpp(1206) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int 1>c:\code\work\cmake-mds\build-vc9\third_party\boost\1.48.0\include\boost\bind\bind.hpp(1207) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int 1>c:\code\work\cmake-mds\build-vc9\third_party\boost\1.48.0\include\boost\bind\bind.hpp(1209) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int 1>c:\code\work\cmake-mds\build-vc9\third_party\boost\1.48.0\include\boost\bind\bind.hpp(1210) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int They point to this code in bind.hpp: BOOST_BIND_OPERATOR( ==, equal ) BOOST_BIND_OPERATOR( !=, not_equal ) BOOST_BIND_OPERATOR( <, less ) BOOST_BIND_OPERATOR( <=, less_equal ) BOOST_BIND_OPERATOR( >, greater ) BOOST_BIND_OPERATOR( >=, greater_equal ) BOOST_BIND_OPERATOR( &&, logical_and ) BOOST_BIND_OPERATOR( ||, logical_or ) Any idea why this is failing? If more info is needed please let me know. --------- Robert Dailey

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boost.asio lib and CodeLite
by Teemu 15 Mar '12

15 Mar '12

hi group! I´m using CodeLite + MinGW+ Unit Test 1.3 on a Win7 system. Now I want to add the boost.asio library (boost_1_49_0) to CodeLite. I have already linked a few files like: "C:\boost_1_49_0\boost\asio" or "C:\MinGW\include\boost" and so on... But I still get some warnings like: "c:\mingw\bin\../lib/gcc/mingw32/4.4.1/../../../../include/boost/asio/detail/impl/win_object_handle_service.ipp: In member function 'void boost::asio::detail::win_object_handle_service::move_construct(boost::asio::detail::win_object_handle_service::implementation_type&, boost::asio::detail::win_object_handle_service::implementation_type&)': c:\mingw\bin\../lib/gcc/mingw32/4.4.1/../../../../include/boost/asio/detail/impl/win_object_handle_service.ipp:106: error: '::UnregisterWaitEx' has not been declared" I´m not sure, if I have add the boost.asio library correctly and ifI have to link some other libraries from the Windows system? I´ve read somewhere that adding Win-files is necessary to run the boost.asio lib correctly, is that right? and if, which files? I hope someone can help me... best regards Teemu sry for my bad english I´m from germany... -- View this message in context: http://boost.2283326.n4.nabble.com/boost-asio-lib-and-CodeLite-tp4474767p44… Sent from the Boost - Dev mailing list archive at Nabble.com.

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