November 2012 - Boost - lists.preview.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

8 8

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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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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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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Why no non-null smart pointers?
by Ross MacGregor 29 Apr '14

29 Apr '14

I just created a very small smart pointer libary for our project. It will contain two types of shared pointers: SharedHandle and NullableSharedHandle. SharedHandle will be a shared pointer that cannot be null by ensuring a non-null construction while NullableSharedHandle will basically be a typedef for boost::shared_ptr. I firmly believe that code can be made more reliable by minimizing the use of nullable pointers. To this end, I think it is important that we start using non-null pointer types. Ideally the compiler would be able to understand a non-null pointer and catch bugs at compile time, but I think we can still improve things with a few runtime checks. If we make sure that a shared pointer is constructed with a non-null pointer and ban any reset() type methods, we guarentee that it points to something. This can be beneficial for the following reasons: 1. Any function that uses this type will no longer be burdened with precondition checks to make sure variables of this type are not null. 2. It's type is simply more explicit and better explains its function. 3. Moving the non-null check to the creation phase will reduce the possibility of encountering null pointer exceptions at runtime (assuming there are many more pointer references than constructor calls). So my little pointer library seems to make a lot of sense, but if so why hasn't this simple smart pointer variation made it into boost yet? Has this been discussed somewhere already? My search on non-null smart pointers is not revealing much discussion on the topic. Regards, Ross

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Interest in Base2/16/32/64 Encoding Library?
by Thomas Kemmer 27 Jan '14

27 Jan '14

Dear Boost Developers, I would like to know if there is interest in incorporating a generic Base2/16/32/64 encoding library into Boost. I am the author of such a libray, hosted at http://code.google.com/p/stlencoders/ and would be willing to contribute and make the effort of "Boostifying" it, if the Boost community is interested in such a thing. There have been several suggestions for a Base64 encoding library on this mailing list in the past. Most of them have been dismissed, since Boost already provides a Base64 implementation with Boost.Serialization's "Dataflow Iterators". Though I appreciate the dataflow iterator's design, from personal experience I think that for the basic task of encoding/decoding, a higher-level interface, e.g. one that takes padding and intermittent whitespace (MIME) into account, would benefit many developers. Currently, the stlencoders library - implements the Base16, Base32 and Base64 encoding schemes as defined in RFC 4648. Base2, i.e. binary encoding, is also supported. - implements encoding and decoding operations as generic algorithms that operate on STL-style iterators - supports different encoding alphabets using custom traits classes - supports different character types - lets the user define if/which non-alphabet characters should be ignored via predicates - provides reasonable performance that matches most "plain C" implementations stlencoders is currently designed as a stand-alone library with no dependencies on Boost (or anything but C++03); it would therefore take some effort and guidance from the community to properly integrate it with the rest of Boost. I would therefore appreciate any feedback regarding your interest in this. Kind Regards, Thomas

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[mpl] integral_c [type_traits] integral_constant limits
by vicente.botet 21 Oct '13

21 Oct '13

Hi, I was testing Boost.Ratio with gcc-4.6 c++0x and I get some compile errors when instantiating std::cout << boost::mpl::integral_c< boost::intmax_t, boost::integer_traits<boost::intmax_t>::const_max >::value ; ..\..\..\../boost/mpl/aux_/integral_wrapper.hpp: In instantiation of 'mpl_::integral_c<long long int, 0x7fffffffffffffffll>': ratio_io\ratio_io.pass.cpp:24:6: instantiated from here ..\..\..\../boost/mpl/aux_/integral_wrapper.hpp:72:96: warning: integer overflow in expression [-Woverflow] ..\..\..\../boost/mpl/aux_/integral_wrapper.hpp:72:96: error: '-0x8000000000000000ll' is not a valid template argument for type 'long long int' because it is a non-constant expression ..\..\..\../boost/mpl/aux_/integral_wrapper.hpp:72:96: error: '-0x8000000000000000ll' is not a constant expression integral_wrapper.hpp:72 contains typedef AUX_WRAPPER_INST( BOOST_MPL_AUX_STATIC_CAST(AUX_WRAPPER_VALUE_TYPE, (value + 1)) ) next; The same line pass with gcc-4.6, gcc-4.5 and gcc-4.5 c++0x with just a warning. ..\..\..\../boost/mpl/aux_/integral_wrapper.hpp: In instantiation of 'mpl_::integral_c<long long int, 0x7fffffffffffffffll>': ratio_io\ratio_io.pass.cpp:23:6: instantiated from here ..\..\..\../boost/mpl/aux_/integral_wrapper.hpp:72:96: warning: integer overflow in expression [-Woverflow] integral_c is by integral_constant, but integral_constant doesn't needs next a prior types. This means that with the current implementation we can not use integral_constant with the max value of the type. Do you think this is a bug in integral_constant? Best, _____________________ Vicente Juan Botet Escribá http://viboes.blogspot.com/

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[scope_exit] D-style scope(failure) and scope(success) in C++
by Evgeny Panasyuk 30 Sep '13

30 Sep '13

Hello all, D language has scope(exit), scope(success) and scope(failure) features - http://dlang.org/statement.html#ScopeGuardStatement : "... scope(exit) executes NonEmptyOrScopeBlockStatement when the scope exits normally or when it exits due to exception unwinding. scope(failure) executes NonEmptyOrScopeBlockStatement when the scope exits due to exception unwinding. scope(success) executes NonEmptyOrScopeBlockStatement when the scope exits normally. ..." Andrei Alexandrescu describes some of uses cases for scope(exit), scope(success), scope(failure) at his recent talk : http://channel9.msdn.com/Events/Lang-NEXT/Lang-NEXT-2012/Three-Unlikely-Suc… There is Boost.ScopeExit library which emulates D's scope(exit) via BOOST_SCOPE_EXIT macro, but there are no analogues for D's scope(failure) and scope(success). Current alternative for these features is ScopeGuard idiom ( http://en.wikibooks.org/wiki/More_C%2B%2B_Idioms/Scope_Guard , http://www.drdobbs.com/cpp/generic-change-the-way-you-write-excepti/1844037… ). Boost.ScopeExit library itself suggests to use ScopeGuard - http://www.boost.org/doc/libs/1_51_0/libs/scope_exit/doc/html/scope_exit/al… : " Boost.ScopeExit is similar to scope(exit) feature built into the D programming language. A curious reader may notice that the library does not implement scope(success) and scope(failure) of the D language. Unfortunately, these are not possible in C++ because failure or success conditions cannot be determined by calling std::uncaught_exception (see Guru of the Week #47 for details about std::uncaught_exception and if it has any good use at all). However, this is not a big problem because these two D's constructs can be expressed in terms of scope(exit) and a bool commit variable (similarly to some examples presented in the Tutorial section). " I have made small library ( https://github.com/panaseleus/stack_unwinding#d-style-scope-guardsactions ) which supplies primitives (class unwinding_indicator, UNWINDING_AWARE_DESTRUCTOR macro) to determining when object destructor is called due to stack-unwinding or due to normal scope leaving. Currently it is implemented on top of platform-specific implementation of uncaught_exception_count function and tested on: {MSVC2005, MSVC2008, MSVC2010, MSVC2012, GCC4.1.2, GCC4.4.6, Clang3.2}x{x32, x64}x{default settings}. uncaught_exception_count is a function similar to std::uncaught_exception from standard library, but instead of boolean result it returns unsigned int showing current count of uncaught exceptions. Such primitives allow us to implement scope(success) and scope(failure) features in C++. I have made several proof-of-concepts: * https://github.com/panaseleus/stack_unwinding/blob/master/examples/scope_ac… * https://github.com/panaseleus/stack_unwinding/blob/master/examples/example_… * https://github.com/panaseleus/stack_unwinding/blob/master/examples/scope_gu… * https://github.com/panaseleus/stack_unwinding/blob/master/examples/boost_sc… boost_scopes.cpp example shows usage of BOOST_SCOPE_FAILURE and BOOST_SCOPE_SUCCESS: try { cout << "Case #1: stack unwinding" << endl; BOOST_SCOPE_EXIT(void) { cout << "exit" << endl; } BOOST_SCOPE_EXIT_END BOOST_SCOPE_FAILURE(void) { cout << "failure" << endl; } BOOST_SCOPE_FAILURE_END BOOST_SCOPE_SUCCESS(void) { cout << "success" << endl; } BOOST_SCOPE_SUCCESS_END throw 1; } catch(int){} { cout << "Case #2: normal exit" << endl; BOOST_SCOPE_EXIT(void) { cout << "exit" << endl; } BOOST_SCOPE_EXIT_END BOOST_SCOPE_FAILURE(void) { cout << "failure" << endl; } BOOST_SCOPE_FAILURE_END BOOST_SCOPE_SUCCESS(void) { cout << "success" << endl; } BOOST_SCOPE_SUCCESS_END } Output is: " Case #1: stack unwinding failure exit Case #2: normal exit success exit " Currently BOOST_SCOPE_FAILURE and BOOST_SCOPE_SUCCESS are implemented based on boost_1_51_0/boost/scope_exit.hpp by copy-paste and replace (just for proof-or-concept, of course it is possible solution with much less duplication). Semantically meaningful changes can be viewed as diff at https://github.com/panaseleus/stack_unwinding/commit/d5513404323490ea99d9b6… Before posting here, I made posts on several C++ forums, but unfortunately get only a few feedbacks regarding ScopeFailure and ScopeSuccess. What do you think? Thank you. P.S. Related discussion: http://lists.boost.org/Archives/boost/2010/09/171051.php Best Regards, Evgeny Panasyuk

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[asio] Randomly having problems reading from the socket
by Torben Wiggerich 29 Jul '13

29 Jul '13

Hi all, I have some problems using the boost.asio.read for a TCP-socket. So far it works fine, but it randomly stops the transfer for at least 5 seconds. To resolve the error I used a simple synchronous server and client from the boost examples and modified it too send a larger amount of data. (307400 Bytes; this size comes from the program I'm trying to get run). On the client side I also changed the reading from the socket to read the complete data with boost.asio.read and transfer_all as argument. Both, server and client, measure the time for sending and reading to the socket and will give an error if it needs more than 1 second. Here is the sourcecode for the server: #include <iostream> #include <string> #include <boost/asio.hpp> #include <boost/date_time/posix_time/posix_time.hpp> using boost::asio::ip::tcp; using namespace boost::posix_time; int main() { try { boost::asio::io_service io_service; tcp::acceptor acceptor(io_service, tcp::endpoint(tcp::v4(), 8002)); tcp::socket socket(io_service); acceptor.accept(socket); unsigned char * array = new unsigned char[307400]; for (;;) { boost::system::error_code ignored_error; ptime startTime = microsec_clock::universal_time(); boost::asio::write(socket, boost::asio::buffer( array, 307400 ), boost::asio::transfer_all(), ignored_error); time_duration neededTime = microsec_clock::universal_time() - startTime; if ( neededTime.total_milliseconds() > 1000 ) { std::cout << "ERROR needed too much time: " << neededTime.total_milliseconds() << "ms" << std::endl; } } } catch (std::exception& e) { std::cerr << e.what() << std::endl; } return 0; } My client sourcecode: #include <iostream> #include <boost/array.hpp> #include <boost/asio.hpp> #include <boost/date_time/posix_time/posix_time.hpp> using boost::asio::ip::tcp; using namespace boost::posix_time; int main(int argc, char* argv[]) { try { if (argc != 2) { std::cerr << "Usage: client <host>" << std::endl; return 1; } boost::asio::io_service io_service; boost::asio::ip::tcp::endpoint endpoint( boost::asio::ip::address::from_string( argv[1] ), 8002 ); tcp::socket socket(io_service); boost::system::error_code error = boost::asio::error::host_not_found; socket.connect( endpoint, error ); if (error) throw boost::system::system_error(error); int counter = 0; unsigned char* array = new unsigned char[307400]; for (;;) { boost::system::error_code error; ptime startTime = microsec_clock::universal_time(); size_t len = boost::asio::read( socket, boost::asio::buffer( array, 307400 ), boost::asio::transfer_all(), error ); time_duration neededTime = microsec_clock::universal_time() - startTime; if ( error ) { printf( "body read error %s\n", error.message().c_str() ); } if ( counter % 5000 == 0 ) { std::cout << "passed: " << counter << "\r"; } ++counter; if ( neededTime.total_milliseconds() > 1000 ) { std::cout << "ERROR needed too much time: " << neededTime.total_milliseconds() << "ms" << std::endl; } } } catch (std::exception& e) { std::cerr << e.what() << std::endl; } return 0; } To reproduce the error just let it run for a while. It can take up to 30 minutes or even more... After a while it will produce the line: "ERROR needed too much time: 5007ms". Maybe with slightly different times, but all around 5 seconds. I tested it on different machines with Windows Vista and Seven. So am I'm doing sth. wrong? Is the reading from the socket correct? I'm using boost version 1.44. Kind regards Torben Wiggerich

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A more convenient Variant visitation syntax
by Kevin Wu Won 19 Jul '13

19 Jul '13

While Boost Variant is a wonderful library that fills a genuine hole in the C++ language, it is not as nice to use as it could be. The "correct" way to unwrap a variant is to apply a static visitor, but this method carries a high syntactic burden because it needs the user to define a class (probably somewhere far away) just so they can "switch" on the type of the object stored in the variant. I came up with a solution where the handler functions can be specified inline with C++11 lambdas. Here's an example: boost::variant< int, std::string > u("hello world"); int result = match(u, [](int i) -> int { return i; }, [](const std::string & str) -> int { return str.length(); }); The `match` function accepts the variant followed by the handler functions. The functions can be specified in any order. It will fail to compile if the functions do not match the types of the variant, if the return types are not all the same, or if a non-unary function is supplied. This is C++11 only because it's quite pointless without lambda functions. I've tested it with gcc 4.7. It doesn't work on gcc 4.6, which can't handle the variadic templates. Here's the code: https://github.com/exclipy/inline_variant_visitor What do you think? This started out for me as an exercise to learn template metaprogramming and C++11, but hopefully, it can actually evolve into something useful.

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De Bruijn Bind (alternate bind syntax) Interest?
by David Sankel 24 Jun '13

24 Jun '13

Hello all, I've been working on an alternate bind syntax based on De Bruijn indices[1]. The syntax is very simple, yet the terms are very powerful. Here is an example of a function const that takes in an argument c and returns another function that, for all input, returns c: //λx.λy.x = λλ1 with De Bruijn indices. auto const_ = abs<1>( abs<1>( var<1,0>() ) ); More examples, further explanation, and an implementation are available here[2]. I'm thinking that this library could also be useful as a core for more syntax heavy bind variations. David [1] http://en.wikipedia.org/wiki/De_Bruijn_index [2] http://bitbucket.org/camior/de-bruijn-bind/ -- David Sankel Sankel Software www.sankelsoftware.com 585 617 4748 (Office)

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[TypeErasure] references
by Chapman, Alec 10 May '13

10 May '13

Hi Steven, I have a somewhat-generic type erasure class that I would like to switch to yours. The main difficulty I can see is in the way capturing by reference is handled. The approach I take in my class is to pass a boost::reference_wrapper to the constructor: typedef mpl::vector<copy_constructible<>, type_id_<>, incrementable<> > requirements; int i = 0; any<requirements> x(boost::ref(i)); // capture i by reference ++x; // i == 1 any<requirements> y(x); // makes a copy of i ++y; // i == 1, any_cast<int>(y) == 2 My motivation is that I have a bunch of template functions already written that I often call directly, but in other cases I need to compile them separately by instantiating them with any<...>: ---------------------- module 1 ------------------------- // some long algorithm that I don't want to modify to be aware of any<...> template<class T> void f(T& t) { ++t; T t2 = t; ++t2; // do something with t2 } // make a type-erased version for separate compilation void any_f(any<requirements>& x) { return f(x); } -------------------- module 2 ---------------------------- // provide a thin wrapper that applies type erasure before calling any_f template<class T> void f_fwd(T& t) { any<requirements> x(boost::ref(t)); any_f(x); } // some function that needs to call f void g(int& i) { // do something with i... // then pass it to f f_fwd(i); } Is something like this possible with your method? Are there advantages that I'm not seeing to having the type signature contain information about whether the object is held by reference? Thanks, Alec

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What Should we do About Boost.Test?
by Dave Abrahams 16 Apr '13

16 Apr '13

Hi All, I was just going through Boost.Test to try to figure out how to teach it, and while it looks to have substantial value, it is also in quite a mess. It contains loads of features that are exercised in the examples/ directory but neither included in any of the tests nor documented. There are facilities for command-line argument parsing! There are "decorators" that turn on/off features for test cases. There is support for mock objects! These are cool and sometimes necessary features, but who knew? The third tutorial page (http://www.boost.org/doc/libs/1_51_0/libs/test/doc/html/tutorials/new-year-…) has a glaring typo in the code examples: "BOOST_AUTO_EST_CASE". There's no reference manual at all. There are nearly-identical files in the examples/ directory called "est_example1.cpp" and "test_example1.cpp" (Did the "t" key on someone's keyboard break?) I could go on, but where would I stop? I don't know what to do about this. Because of the lack of redundancy (i.e. tests and documentation), it's hard to tell whether this library is correct or even to define what "correct" should mean. It seems like, as long as the code is incompletely / incorrectly documented and tested, it's just someone's personal coding project that we happen to keep shipping with Boost, and not really a library for general use. This situation reflects poorly on Boost as a whole and the fact that it centers around a _testing_ library, which is concerned with robustness... well, let's just say that the irony isn't lost on me. I don't mean this posting as an attack on Gennadiy in any way, but I think the situation is unacceptable and therefore am opening a discussion about what should happen. As a straw man, I'll make this suggestion: - Boost.Test is officially deprecated in the next release - Its documentation, such as it is, is removed from the release after that - Meanwhile, other tests in Boost that use this library are rewritten to use a different mechanism - The code is removed from Boost thereafter I am not at all attached to removing Boost.Test from Boost, but IMO rescuing it would require a significant new investment of time and energy from people who are committed to bringing the library up to par with the rest of what we do. (I seriously thought about volunteering for this myself, but realistically speaking, I don't have the time, and volunteering for something you can't actually do is worse than not volunteering at all.) Even if volunteers show up, I'd suggest proceeding with the plan above, subject to reversal at any time the work actually gets done. Thoughts? -- Dave Abrahams BoostPro Computing Software Development Training http://www.boostpro.com Clang/LLVM/EDG Compilers C++ Boost

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[fusion] What do we do with nil ?
by Joel de Guzman 31 Mar '13

31 Mar '13

Hello, This is a constantly nagging issue. There are a couple of places where nil is a PP define especially on the Mac: - objc.h #ifndef nil #define nil __DARWIN_NULL #endif and - MacTypes.h #ifndef nil #define nil NULL #endif So people complain because fusion uses nil as: namespace boost { namespace fusion { struct nil; }} So, nil is a reserved word in Objective-C. But this is C++! And that define is SUCH A BAD PRACTICE in C++! Some folks, like Paul Mensonides maintains a strong stance against this: I would just use #define nil nil as a sanity check and call it done. If the symbol is already defined, compilation error (or at least warning on overly permissive compilers). The symbol will be need to be undefined in between the inclusion of the two libraries. Workarounds like nil_ and (min)(...) just perpetuate the problem. Fix the root problem rather than treating the symptom indefinitely. Otherwise, where is the line drawn? Even if you can't provide a transparent fix (such as defining nil as a constant and min/max as functions), the backwards compatibility argument fails in the long run. The amount of effort required to make the necessary changes to existing code will eventually be outweighed by the effort to implement workarounds put into new code (as well as educate everyone that they are necessary)--especially in cases like these which can mostly be emulated in a way that causes most existing code to work. As I said over and over again, I'm listening and I would want to "fix" this issue if someone comes up with a reasonable (tested) patch that: 1) Detects the platform 2) Renames fusion::nil to something else (only for the affected platform) Yet, no-one wants to do this. Instead we get nasty remarks such as those found here: https://svn.boost.org/trac/boost/ticket/5010#comment:16 What do we do? I'm seeking for a resolution. Regards, -- Joel de Guzman http://www.boostpro.com http://boost-spirit.com

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[config] consexpr workaround
by vicente.botet 21 Mar '13

21 Mar '13

Hi, in order to make easier the introduction of constexpr in a portable way I would like we add a Boost Config workarround. We can define some macros depending on whether BOOST_NO_CONSTEXPR is defined or not. #if defined(BOOST_NO_CONSTEXPR) #define BOOST_CONSTEXPR #define BOOST_CONSTEXPR_OR_CONST const #else #define BOOST_CONSTEXPR constexpr #define BOOST_CONSTEXPR_OR_CONST constexpr #endif For most of the constexpr functions or constructors BOOST_CONSTEXPR will work. constexpr tuple(); =versus= BOOST_CONSTEXPR tuple(); When used for static constants BOOST_CONSTEXPR_OR_CONST is needed as we need to preserv the const keyword when consexpr is not available. static constexpr UIntType xor_mask = a; =versus= static BOOST_CONSTEXPR_OR_CONST UIntType xor_mask = a; We could also add a STATIC_CONSTEXPR macro #define BOOST_STATIC_CONSTEXPR static BOOST_CONSTEXPR_OR_CONST static constexpr UIntType xor_mask = a; =versus= BOOST_STATIC_CONSTEXPR UIntType xor_mask = a; For this case the existing macro BOOST_STATIC_CONSTANT could be modified to use BOOST_CONSTEXPR_OR_CONST when static const was used. static constexpr UIntType xor_mask = a; =versus= BOOST_STATIC_CONSTANT(UIntType, xor_mask = a); Can we introduce this workaround? Best regards, Vicente _____________________ Vicente Juan Botet Escribá http://viboes.blogspot.com/

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[thread] thread_specific_ptr leaks on VS2012 when using std::async()
by Klaim - Joël Lamotte 05 Mar '13

05 Mar '13

Hi, The title says it all. I think I found a memory leak with the help of boost.log author Andrei Semashev. I was using Boost.Log in Visual Studio 2012 (released one) and tried to use Visual Leak Detector because Visual Studio basic leak detector was reporting leaks. I isolated the leaks to usage of log and switched to VLD to check if the basic detector wasn't giving me false positive. I contacted Andrei to see if he could check it but he don't have VS2012 available so I setup some tests to isolate the problem. In the end of our exchange we concluded it was a false positive (it only leak on end of program). However it is still an annoying noise in the leak report logs, so people not understanding the source of this problem might be interested in this email. I attach the whole email exchange to this email, tell me if leak logs are necessary too. The last version of my test is at the end of the email (first program). Basically, the leak appear only when using std::async() in combination of boost::thread_specific_ptr : - using exclusively boost threading libraries (both with dynamic and static linking) result in no leak - using exclusively std threading libraries but not std::async() result in no leak - using std::async() result in a leak The second test program shows that using Intel Threading Building Blocks, I get leaks only if : - I use std::async() in combination with boost::thread_specific_ptr, as before (I mean I use tbb without a leak, then I add a std::async() call to the same task function and there is a leak) - I don't use std::async() but I don't manage the lifetime of tbb task scheduler We think the threads spawned by both tbb (that is supposed to be a superset of ppl) and std::async() (that is supposed to use ppl/concrt task scheduler) are not ended yet when the program reach the end of main (which seems logical as the task scheduler is then managed as a static global), making boost::thread_specific_ptr not release some data on thread destruction, as it is notified too late and any leak detection tool willl generate noise due to this. A way to fix this is to explicitely end the task scheduler, being tbb or ppl/concrt. I will use tbb task scheduler explicitely initialized/terminated in my project so it will solve the problem on my side. Joel Lamotte ------------------------------------ // this program was used to see the memory leak #define TEST_ASYNC // comment this to make it linear and not leak //#define WITH_BOOST_THREADS #define WITH_STD_ASYNC // uncomment this to leak //#define WITH_BOOST_LOG // boost log also leak if std::async is used #include <boost/thread.hpp> #ifdef WITH_BOOST_THREADS # include <boost/thread/future.hpp> # include <boost/chrono.hpp> # define THIS_THREAD boost::this_thread # define THREAD_LIB boost::thread # define CHRONO_LIB boost::chrono # define MY_FUTURE boost::future #else # include <future> # include <thread> # include <chrono> # define THIS_THREAD std::this_thread # define THREAD_LIB std::thread # define CHRONO_LIB std::chrono # define MY_FUTURE std::future #endif #ifdef WITH_BOOST_LOG # include <boost/log/trivial.hpp> # define MY_LOG BOOST_LOG_TRIVIAL(info) #else # include <iostream> # define MY_LOG std::cout << '\n' #endif #define BASIC_VS_LEAK_DETECTOR 0 #define VISUAL_LEAK_DETECTOR 1 #define LEAK_DETECTOR VISUAL_LEAK_DETECTOR #if LEAK_DETECTOR == BASIC_VS_LEAK_DETECTOR # define _CRTDBG_MAP_ALLOC # include <stdlib.h> # include <crtdbg.h> #else # include "vld.h" #endif struct my_data { char data[1024]; my_data() { MY_LOG << "CONSTRUCTOR my_data - " << THIS_THREAD::get_id(); } ~my_data() { MY_LOG << "DESTRUCTOR my_data - " << THIS_THREAD::get_id(); } }; boost::thread_specific_ptr< my_data > ts_ptr; void my_thread_foo() { ts_ptr.reset(new my_data()); } int work() { for( int i = 0; i < 42; ++i ) { MY_LOG << "THIS IS A MESSAGE - I = " << i; MY_LOG << "ts_ptr = " << ts_ptr.get(); my_thread_foo(); THIS_THREAD::sleep_for( CHRONO_LIB::milliseconds(10) ); } return 0; } int main(int argc, char *argv[]) { #if LEAK_DETECTOR == BASIC_VS_LEAK_DETECTOR // First simple memory leak detection for Visual Studio // use _crtBreakAlloc to put a breakpoint on the provided memory leak id allocation //_crtBreakAlloc = 1149; _CrtSetDbgFlag ( _CRTDBG_ALLOC_MEM_DF | _CRTDBG_LEAK_CHECK_DF ); #endif //int* k = new int[42]; // to check that memory leak detection does work MY_LOG << "Hello, World!"; #ifdef TEST_ASYNC # ifndef WITH_BOOST_THREADS std::vector< std::future<int> > work_in_progress(2); # ifdef WITH_STD_ASYNC for( auto& ftr : work_in_progress ) { ftr = std::async( work ); } # else for( auto& ftr : work_in_progress ) { std::packaged_task< int() > task(work); ftr = task.get_future(); std::thread thread( std::move(task) ); thread.detach(); } # endif for( auto& ftr : work_in_progress ) { ftr.get(); } # else std::vector< boost::unique_future<int> > work_in_progress(42); for( auto& ftr : work_in_progress ) { boost::packaged_task<int> task(work); // boost's packaged_task don't take the full signature as parameter, it takes the return type only ftr = task.get_future(); boost::thread thread( boost::move(task) ); thread.detach(); } for( auto& ftr : work_in_progress ) { ftr.get(); } # endif #else for( int i = 0; i < 42; ++i ) { work(); } #endif MY_LOG << "END"; return EXIT_SUCCESS; } -------------------------------------- // this program tests if the memory leaks appear with Threading Building Blocks #define BASIC_VS_LEAK_DETECTOR 0 #define VISUAL_LEAK_DETECTOR 1 #define LEAK_DETECTOR VISUAL_LEAK_DETECTOR #define WITH_ROOT_TASK //#define WITH_BOOST_LOG //#define WITH_STD_ASYNC // uncomment to leak #ifdef WITH_STD_ASYNC # include <future> #endif #include <thread> #include <atomic> #include <boost/thread.hpp> #include <tbb/tbb.h> #include <tbb/task_scheduler_init.h> #ifdef WITH_BOOST_LOG # include <boost/log/trivial.hpp> # define MY_LOG BOOST_LOG_TRIVIAL(info) #else # include <iostream> # define MY_LOG std::cout << '\n' #endif #if LEAK_DETECTOR == BASIC_VS_LEAK_DETECTOR # define _CRTDBG_MAP_ALLOC # include <stdlib.h> # include <crtdbg.h> #else # include "vld.h" #endif namespace test { struct my_data { char data[1024]; }; boost::thread_specific_ptr< my_data > ts_ptr; void my_thread_foo() { ts_ptr.reset(new my_data()); } class UpdateTask : public tbb::task { public: UpdateTask() : idx( s_idx++ ) { MY_LOG << "[UpdateTask " << idx << " ] " << std::endl; } ~UpdateTask() { MY_LOG << "[/UpdateTask " << idx << " ]" << std::endl; } tbb::task* execute() { MY_LOG << "[" << std::this_thread::get_id() << "] Tick "<< m_count <<std::endl; my_thread_foo(); ++m_count; if( m_count < 100 ) { // make sure this is re-executed this->increment_ref_count(); this->recycle_as_safe_continuation(); } return nullptr; } private: static std::atomic<int> s_idx; std::atomic<int> m_count; const int idx; }; std::atomic<int> UpdateTask::s_idx = 0; class TaskScheduler // using TBB { public: #ifdef WITH_ROOT_TASK TaskScheduler() : m_root_task( *new (tbb::task::allocate_root()) tbb::empty_task ) { m_root_task.increment_ref_count(); } ~TaskScheduler() { m_root_task.destroy(m_root_task); } #endif void register_update_task() { #ifdef WITH_ROOT_TASK m_root_task.increment_ref_count(); UpdateTask& updater = *new(m_root_task.allocate_child()) UpdateTask(); #else UpdateTask& updater = *new(tbb::task::allocate_root()) UpdateTask(); #endif m_task_list.push_back( updater ); } void run_and_wait() { #ifdef WITH_ROOT_TASK m_root_task.spawn( m_task_list ); m_root_task.wait_for_all(); #else tbb::task::spawn_root_and_wait( m_task_list ); #endif } private: tbb::task_list m_task_list; // uncomment the following line to not leak tbb //tbb::task_scheduler_init m_engine_instance; // We explicitly create and destroy the TBB task scheduler to avoid memory leak warning noises. #ifdef WITH_ROOT_TASK tbb::task& m_root_task; #endif }; void tbb_test() { TaskScheduler task_scheduler; for( int i = 0; i < 50; ++i ) { task_scheduler.register_update_task(); } task_scheduler.run_and_wait(); } } int main(int argc, char *argv[]) { #if LEAK_DETECTOR == BASIC_VS_LEAK_DETECTOR // First simple memory leak detection for Visual Studio // use _crtBreakAlloc to put a breakpoint on the provided memory leak id allocation //_crtBreakAlloc = 148; _CrtSetDbgFlag ( _CRTDBG_ALLOC_MEM_DF | _CRTDBG_LEAK_CHECK_DF ); #endif #ifdef WITH_STD_ASYNC std::atomic<bool> finished = false; std::async( [&]{ while( !finished ) { MY_LOG << "POP"; test::my_thread_foo(); std::this_thread::sleep_for( std::chrono::milliseconds(500) ); } } ); #endif test::tbb_test(); #ifdef WITH_STD_ASYNC finished = true; #endif MY_LOG << "\nEND"; std::this_thread::sleep_for( std::chrono::seconds(4) ); return 0; }

3 5

[thread] boost::thread and thread safety annotations
by Wladimir 04 Mar '13

04 Mar '13

Hello, The Clang C++ compiler project is currently working on a thread safety analyzer. By making use of so-called thread safety annotations within the source code, several problems with synchronization primitives can be found statically. For example: usage of a data structure without acquiring its guarding lock. See here for an overview of the available attributes: http://clang.llvm.org/docs/LanguageExtensions.html#threadsafety It is customary to use these attributes by defining macros, for compatibility: http://www.mail-archive.com/linuxkernelnewbies@googlegroups.com/msg01455.ht… At one time, it was also supposed to end up in G++, but this was abandoned in favor of clang (see http://gcc.gnu.org/wiki/ThreadSafetyAnnotation) But at least the annotations are fairly standardized. I think it would be useful to add these annotations to boost::thread, so that projects using that library can make use of the static checking. As I understand it, is only a matter of marking data structures that serve as lock/scoped_lock (such as boost::mutex, boost::recursive_mutex, ...), and methods that act upon the lock with the appropriate attributes. Any interest in this? Regards, Wladimir

2 1

Fwd: [Thread] Solution to conflict with MFC?
by Thorsten Ottosen 28 Feb '13

28 Feb '13

Hi Thread maintainers, Anthony speaks about a patch to make this work. Does anyone know where it is? And could it be applied? Thanks -Thorsten -------- Original Meddelelse -------- Subject: [Thread] Solution to conflict with MFC? Date: Tue, 26 Apr 2011 13:28:56 +0200 From: Christian Larsen <contact(a)dword.dk> Reply-To: boost-users(a)lists.boost.org To: boost-users(a)lists.boost.org Newsgroups: gmane.comp.lib.boost.user Hello, I know this has been asked before, but I could not find a good solution. I'm experiencing problems with an application using both MFC and Boost.Thread. Specifically the assertion ASSERT(AfxGetModuleState() != AfxGetAppModuleState()); in AfxCoreInitModule() fails. I link Boost.Thread statically into a DLL in my project. From previous posts to this list and elsewhere, e.g. http://lists.boost.org/boost-users/2009/04/46929.php, I see that the issue is caused by setting _pRawDllMain in tss_pe.cpp. Commenting this line does "solve" the problem, but I would rather not have to hack the Boost source code this way. It seems there is a patch somewhere for this problem (referred to in http://lists.boost.org/boost-users/2009/04/47015.php) but it appears it never made it into the source. Is there any chance of this issue being solved in a better way? Best regards, Christian Larsen

5 9

[Config] N3276 decltype support on VC++ 11
by Michel Morin 28 Feb '13

28 Feb '13

IIRC, Stephan said that VC++ 11 supports N3276 decltype. Shall we "undef" BOOST_NO_CXX11_DECLTYPE_N3276 for VC++ 11? This enables automatic use of decltype-based `boost::result_of`. Trivial patch attached. Regards, Michel

11 79

[multi_index] Move Semantics
by Mark Snelling 27 Feb '13

27 Feb '13

Hi, I've been a user of Boost.MultiIndex for a number of years and think it's a great library. Is there any firm plan to add move semantics? It's been noted under "Future Work" in the docs since Boost 1.32. Regards, Mark

6 10

[Lockfree] ringbuffer
by Rich E 17 Feb '13

17 Feb '13

First off, all Boost.Lockfree tests in trunk are passing for me on clang 4.0 on OS X, hurrah! Thank you Tim for working on this for so long... I'm running through the examples now, only with the outdated documentation as a guide (more than a couple years old). I cannot find the ringbuffer container - was it renamed or removed altogether during the review period? I notice spsc_queue acts awefully like a ringbuffer, and it's implementation contains many

2 6

[fixed_point] Request for interest in a binary fixed point library
by Vicente J. Botet Escriba 02 Feb '13

02 Feb '13

Hi, the recent discussion on the MultiplePrecission Arithmetic library has show that some people has its ow fixed point library. Is there an interest in a Boost library having as base http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2012/n3352.html? I have started a prototype http://svn.boost.org/svn/boost/sandbox/fixed_point (there is no doc yet but the basic goal is quite close to the N3352 C++ proposal). This prototype should allow you to play a little bit with. If yes, what would you like to be changed, added or improved in n3352? Next follows some design decisions that IMO need to be decided before hand. * Should integers and reals be represented by separated classes? * Should signed and unsigned be represented by separated classes? * Should the library use a specific representation for signed numbers (separated sign, 2-complement? Let the user choose? * Should the library provide arbitrary range and resolution and allocators? * Should the library be open to overflow and rounding or just implement some of the possible policies? and in this case which ones? * Should fixed_point be convertible to/from integer/float/double? * Could the result of an arithmetic operation have more range and resolution than his arguments? * Is there a need for a specific I/O? * is there a need for radix other than 2 (binary)? * Should the library implement the basic functions, or should it imperatively implement the C++11 math functions? Could a first version just forward to the c++11 math functions? * Should the library support just one of the know ways to name a fixed-point, a U(a,b), nQm, ...? Provide some ways to move from one to another? * Could expect the same/better performances respect to hand written code? * What should be the size used by a fixed_point instance? _fast? _least? Should the user be able to decide which approach is better for his needs? * Which should be the namespace? boost? boost/fixed_point? boost/binary_fixed_point? boost/bfp? ... * others you can think of. Please, replay if you are interested, have some experience in the domain, good ideas, .. Best regards, Vicente

6 44

[variant] Basic rvalue and C++11 features support
by Antony Polukhin 20 Jan '13

20 Jan '13

Hi, There is a patch in ticket #7620 that adds some rvalue assignment operators and rvalue constructors for Boost.Variant library. I saw no activity from authors of Boost.Variant Eric Friedman and Itay Maman for a long time, so if there will be no objections, I'll commit patch to trunk in the middle of November. Any suggestions and comments are welcomed. -- Best regards, Antony Polukhin

19 74

Changes to VS 2012 config
by Marshall Clow 17 Jan '13

17 Jan '13

Just so people know - I'm updating the Visual Studio configuration to more accurately reflect the capabilities of VS 2012. The first step was in http://svn.boost.org/trac/boost/changeset/81613 ; the next step will be to update the compiler features. If you see any problems, please let me know. -- Marshall

14 26

[parameter] std proposal
by Lorenzo Caminiti 07 Jan '13

07 Jan '13

Hello all, Is there a C++ standard proposal for named parameter addition? I am looking for an "N-paper" for named parameters similar to N2081 for concepts, or N1962 for contracts. Thank you. -- Sent from my mobile device Lorenzo

6 8

[Range] Proposal: a sub-maintainer of Boost.Range
by Michel Morin 05 Jan '13

05 Jan '13

Dear Neil, Dear Nate, First I'd like to say thank you for your library, Neil. It is a very useful library and it's great fun to writing codes with range adaptors. Boost.Range is one of the most important Boost libraries that are not yet added to the Standard. I know that Neil has made an effort to make time for developing the library, but recently making time for development seems difficult. And there are several open tickets of trivial bugs (e.g. #5603, #6110). Considering this situation, I'd like to make a proposal about Boost.Range: ** Adding a sub-maintainer to Boost.Range ** This reduces author's maintenance burden and also helps more stable development of the library. I recommend Nathan Ridge as a sub-maintainer of Boost.Range. His knowledge, experiences and contribution to Boost are great. If both of Neil and Nate accept the proposal, and if Nate needs some support for the start-up, I'll try my best to support him. I also believe that Jeff will also support him ;) Neil, what do you think about this proposal? I would appreciate and respect any of your reply. Yours sincerely, Michel

11 42

[config] Proposed BOOST_NOEXCEPT_NOTHROW macro
by Beman Dawes 03 Jan '13

03 Jan '13

The three current BOOST_NOEXCEPT* macro variants miss the case where C++03 code has a "throw()" throw-specifier. Classes that derive from standard library exceptions need this to avoid breaking code on C++03 compilers. I'm not enamored with the BOOST_NOEXCEPT_NOTHROW name, so feel free to offer suggestions for alternate names. Here is the full set of macros: #ifdef BOOST_NO_NOEXCEPT # define BOOST_NOEXCEPT # define BOOST_NOEXCEPT_NOTHROW throw() <---- new macro # define BOOST_NOEXCEPT_IF(Predicate) # define BOOST_NOEXCEPT_EXPR(Expression) false #else # define BOOST_NOEXCEPT noexcept # define BOOST_NOEXCEPT_NOTHROW noexcept <---- new macro # define BOOST_NOEXCEPT_IF(Predicate) noexcept((Predicate)) # define BOOST_NOEXCEPT_EXPR(Expression) noexcept((Expression)) #endif Unless there are objections, I'll commit the changes Wednesday afternoon Eastern US time. --Beman

7 11

Re: [boost] Heads up - string_ref landing
by Yanchenko Maxim 19 Dec '12

19 Dec '12

Marshall. low <mclow.lists. at> gmail.com> writes: > Please let me know what you think! As probably everyone, we have our own device for this. Here are some points and experience we gathered. 1. This class is essentially just an iterator_ range<char*> (modulo template for const/wchar_t), so it should either inherit from it or have corresponding converting ctors/operators. In this sense Olaf/Gennadiy's remarks are pretty valid. OTOH size is needed very frequently and having it precomputed is a good thing, so conversion approach seems to be better (but then we lose passing by reference as iterator_range, type_traits etc). I'm not sure what's more important. 2. Given the above, the name is misleading as it's not a reference to std::string. We use name char_range. 3. It's worth having a static constructor 'literal' (templated with size) to construct char_ranges from literals - as the compiler knows their size in compile time (minus zero terminator). It can be a constexpr too. Same manner - static function 'from_array', embrasing an array of chars in whole, assuming there is no zero terminator - useful for working with structures representing messages in char-based protocols with fixed-width fields. 4. (hack) We had to add a member function 'assign' (this is just operator=) to make boost::tokenizer return char_ranges. I don't like this part at all as it contradicts the meaning of say std::vector::assign, so I'd prefer another solution, probably in form of a customization point in boost::tokenizer. Thanks, Maxim

20 115

[graph] A* search applied to knight's tour
by Dave Abrahams 15 Dec '12

15 Dec '12

Hi, I was just trying to work up an example for a class I'm teaching, to illustrate implicit graphs. The following shows how far I've gotten: https://gist.github.com/4153918 This is attempting to apply Warnsdorff's heuristic (choose the next move with the least out-degree) using A* search. I'm running into several problems having to do with the requirements of astar_search_no_init. In particular, the requirement that we can assign an index to every vertex is quite painful, since enumerating all the possible vertices in the search space is difficult. Any advice here? I suppose I could keep a real map and simply assign indices in the order vertices are encountered, but that seems pretty ugly to me. Any hints? -- Dave Abrahams BoostPro Computing Software Development Training http://www.boostpro.com Clang/LLVM/EDG Compilers C++ Boost

2 4

[Interprocess] Experimental Win32 Mutexes
by Brink, Robert (GE Aviation, US) 13 Dec '12

13 Dec '12

I'm running Boost 1.52 on Windows 7, Visual Studio 2010. I noticed in sync\interprocess_mutex.hpp there is a windows mutex implementation that is hidden behind the BOOST_INTERPROCESS_FORCE_GENERIC_EMULATION macro. The comment indicates that it is "Experimental". Could someone shed some light on what is Experimental about it and what the general plans for this feature are? I was having a problem with many processes all spin-locking when allocating shared memory that I traced down to the old mutex implementation for shared memory. I enabled the experimental feature in my local build ( by commenting out the above macro in the detail\workaround.hpp file) and it seems to fix my problems. My performance is much improved. But what are my risks for using this implementation? I'm a little nervous to depend on something marked as "Experimental". Thanks Rob Brink

3 5

Heads up - string_ref landing
by Marshall Clow 12 Dec '12

12 Dec '12

I'm about to check in some new functionality into the string_algo library; an implementation of string_ref. A string_ref is a non-owning reference to a string. It is implemented as a {pointer, length} pair, and is exceedingly useful when parsing, and manipulating strings in "read-only" ways. The header will be in boost/algorithm/string_ref.hpp, but I welcome discussion about where it should live. Ideally, I think it should be just "boost/string_ref.hpp". Basic sanity tests will be checked in with the header file - I have tested on clang, clang11, and gcc. One reason for checking this in now is to get the tests run on lots of different systems. Docs will be coming soon, but http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2012/n3442.html is the proposal for "a future version of C++" ;-) Please let me know what you think! -- Marshall Marshall Clow Idio Software <mailto:mclow.lists@gmail.com> A.D. 1517: Martin Luther nails his 95 Theses to the church door and is promptly moderated down to (-1, Flamebait). -- Yu Suzuki

18 45

Using c++11 features in clang
by Marshall Clow 10 Dec '12

10 Dec '12

In response to a some questions on the boost-users list (and boost bug reports), I wrote up this: http://marshall.calepin.co/llvmclang-and-standard-libraries-on-mac-os-x.html I don't know if this should be a FAQ entry for Boost, or for clang. Suggestions/comments/edits welcome. -- Marshall Marshall Clow Idio Software <mailto:mclow.lists@gmail.com> A.D. 1517: Martin Luther nails his 95 Theses to the church door and is promptly moderated down to (-1, Flamebait). -- Yu Suzuki

3 3

[algorithm][hex] function hex_char_to_int in unnamed namespace in header file
by Felipe Magno de Almeida 10 Dec '12

10 Dec '12

Hello, AFAIK, unnamed namespaces are dangerous in headers. There is a commentary just above the function definition: // this needs to be in an un-named namespace because it is not a template // and might get included in several compilation units. This could cause // multiple definition errors at link time. But it seems the better thing would be to define it inline. It is exactly because it can be used in several translation units that it can cause an ODR violation if defined in a unnamed namespace AFAIK. Regards, -- Felipe Magno de Almeida

3 8

Boost.Test updates in trunk: need for (mini) review?
by Gennadiy Rozenal 09 Dec '12

09 Dec '12

Hi, It's been a long while since I merged any changes into boost release and by now there are whole bunch of new features there. Some are small, but some others are big ones such that they can change the way people use the library. I'd like to list them here (excluding bug fixes and removal of deprecated interfaces) and ask what should we do with these. Specifically let me know if you think these require some kind of (mini) review from community, but any other comments are welcome as well. So here we go: I. New testing tool BOOST_CHECKA This tool is based on excellent idea from Kevlin Henney. I chose the name CHECKA for this tool due to the lack of better name, but I am open to suggestions. This testing tool capable of replacing whole bunch of existing other tools like BOOST_CHECK_EQUAL, BOOST_CHECK_GT etc. Usage is the most natural you can wish for: BOOST_CHECKA( var1 - var2 >= 12 ); And the output will include as much information as we can get: error: in "foo": check var1 - var2 >= 12 failed [23-15<12] II. New "data driven test case" subsystem New data driven test case subsystem represent a generalization of parameterized test case and test case template and eventually will replace both. The idea is to allow user to specify an arbitrary (monomorphic or polymorphic) set of samples and run a test case on each of the samples. Samples can have different arity, thus you can have test cases with multiple parameters of different types. For now we support following dataset kinds (aside of generators none of dataset constructions routines performs *any* copying): a) singleton - dataset constructed out of single sample data::make(10) - singleton dataset with integer sample data::make("qwerty") - singleton dataset with string sample b) array - dataset constructed out of C array int a[] = {1,2,3,4,5,6}; data::make(a) - dataset with 6 integer values c) collection - dataset constructed out of C++ forward iterable collection std::vector<double> v{1.2, 2.3, 3.4, 5.6 }; data::make(v) - dataset with 6 double values d) join - dataset constructed by joining 2 datasets of the same type int a[] = {1,2,3}; int b[] = {7,8,9}; data::make(a) + data::make(b) - dataset with 6 integer values e) zip - dataset constructed by zipping 2 datasets of the same size, but not necessarily the same type This dataset has an arity which is sum of argument dataset arities. int a[] = {1,2,3}; char* b[] = {"qwe", "asd", "zxc"}; data::make(a) ^ data::make(b) dataset with 3 samples which are pairs of int and char*. f) grid - dataset constructed by "multiplying" 2 datasets of the same different sizes and types type This dataset has an arity which is sum of argument dataset arities. int a[] = {1,2,3}; char* b[] = {"qwe", "asd"}; double c[] = {1.1, 2.2}; data::make(a) * data::make(b) * data::make(c) dataset with 12 samples which are tuples of int and char* and double. g) xrange generator dataset which produes samples in some range data::xrange( 0., 3., 0.4 ) - dataset with 8 double samples data::xrange<int>((data::begin=9, data::end=15)) - dataset with 6 int samples data::xrange( 1., 7.5 ) - dataset with 7 double samples data::xrange( 5, 0, -1 ) - dataset with 5 int samples h) random - generator dataset with unlimited number of random samples data::random(data::distribution = std::normal_distribution<>(5.,2)) dataset with random double numbers following specified distribution data::random(( data::engine = std::minstd_rand(), data::distribution = std::discrete_distribution<>(), data::seed = 20UL )); dataset with random int numbers following specified distribution While all this interfaces can be used by itself to build complex datasets with various purposes, primary use case it was developped for is new data driven test case interface: BOOST_DATA_TEST_CASE( test_name, dataset, parameter_names... ) Here are couple examples: int samples1[] = {1,2,3}; BOOST_DATA_TEST_CASE( t1, samples1, sample ) { BOOST_CHECKA( foo(sample) > 0 ); } Above test case is going to be executed 3 times with different sample values char* strs[] = {"qwe", "asd", "zxc", "mkl" }; BOOST_DATA_TEST_CASE( t1, data::xrange(4) ^ strs ^ data::random(), intval, str, dblval ) { MyObj obj( dblval, str ); BOOST_CHECKA( obj.goo() == intval ); } Above test case will be executed 4 times with different values of parameters intval, str, and dblval. Polymorphic datasets are still being developed, but should appear soon(ish). III. Auto-registered test unit decorators. Previously is was not possible and/or convenient to assign attributes to the automatically registered test units. To alleviate this I've introduced a notion of test unit decorator. These can be "attached" to any test unit similarly to like it is done in other languages Following decorators already implemented: label - adds labels to a test unit expected_failures - set expected failures for a test unit timeout - sets timeout for a test unit description - sets a test unit description depends_on - sets a test unit dependency enable_if/disable_if - facilitates a test unit status change fixture - assigns fixture to a test units Test unit description is new test unit attribute, which is reported by new list_content command line argument described below. Usage of labels covered below as well. enable_if/disable_if allow new, much more flexible test management. By adding enable_if/disable_if decorators to the test unit you can conditionally select which test units to run at construction time based on some compile time or run-time parameters. And we finally we have suite level fixtures which are set by attaching fixture decorator to a test suite (suite level fixtures executed once per test suite). Attachment of decorator is facilitated by using of BOOST_TEST_DECORATOR. Note that you can use any of '+', '-', '*' symbols to attach decorator (and any number of '*'): BOOST_TEST_DECORATOR( + unittest::fixture<suite_fixture>() ) BOOST_AUTO_TEST_SUITE( my_suite1 ) { } BOOST_TEST_DECORATOR( - unittest::timeout( 100 ) - unittest::expected_failures( 1 ) - unittest::enable_if( 100 < 50 ) ) BOOST_AUTO_TEST_CASE( my_test5 ) BOOST_TEST_DECORATOR( **** unittest::label( "L3" ) **** unittest::description( "suite description" ) **** unittest::depends_on( "my_suite2/my_test7" ) ) BOOST_AUTO_TEST_CASE( my_test11 ) IV Support for "run by label" plus more improvements for filtered runs Previously you only had an ability to filter test unit to execute by name. Now you can attach labels to test units and create collections to run which are located in arbitrary positions in test tree. For example you can have special label for performance test cases, which is attached to all test units which are responsible for testing performance of your various components. Or you might want to collect exception safety tests etc. To filter test units by level you still use --run_test CLA. Labels are dented by @prefix: test.exe --run=@performance You can now repeat --run_test argument to specify multiple conditions: test.exe --run=@performance,@exception_safety --run=prod/subsystem2 In addition run by name/label now recognizes dependencies. So if test unit A depends on test unit B and test unit B is disabled/is not part of current run test unit A will not run as well. Finally you now have an ability to specify "negative" conditions, by prefixing name or label with ! test.exe --run=!@performance This will run all test units which are not labeled with "performance". V. Support for failure context In many scenarios it is desirable to specify an additional information to a failure, but you do not need to see it if run is successful. Thus using regular print statements is undesirable. This becomes especially important when you develop common routine, which performs your testing and invoke it from multiple test units. In this case failure location is no help at all. To alleviate this problem two new tools are introduced: BOOST_TEST_INFO BOOST_TEST_CONTEXT BOOST_TEST_INFO attaches context to next assertion which is executed. For example: BOOST_TEST_INFO( "a=" << a ); BOOST_CHECKA( foo(a) == 0 ); BOOST_CHECK_CONTEXT attaches context to all assertions within a scope: BOOST_CHECK_CONTEXT( "Starting test foo from subset " << ss ) { BOOST_CHECKA( foo(ss, a) == 1 ); BOOST_CHECKA( foo(ss, b) == 2 ); } VI. Two new command line arguments: list_context, wait_for_debugger Using list_context you can see a full or partial test tree of your test module. wait_for_debugger allows to force test module to wait till you attach debugger. VII. Colored output. Using new CLA --color_output you can turn on colored output for error and information messages VIII New production testing tools interface introduced This feature was covered in details in my presentation in BoostCon 2010. The gist if this is an ability to use Boost.Test testing tools interfaces in production (nothing to do with testing) code. User supplied implementation is plugged in IX. Number of smaller improvements: * Notion of framework shutdown. Allows to eliminate some fake memory leaks * Added checkpoints at fixture entry points, test case entry point and test case exit point for auto registered test cases * New FPE portable interfaces introduced and FPE handling is separated from system errors handling. You can detect FPE even if catch_system_error is false * Added an ability to erase registered exception translator * execution_monitor: new interface vexecute - to be used to monitor nullary functions with no result values * test_tree_visitor interface extended to facilitate visitors applying the same action to all test units * execution_monitor use typeid to report "real" exception type if possible. * New ability to redirect leaks report into a file Thank you for your time, Gennadiy

21 66

[config] Macro for null pointer
by Edward Diener 08 Dec '12

08 Dec '12

I have found something like this to be helpful, when working with multiple compilers: #include <boost/config.hpp> #if defined(BOOST_NO_NULLPTR) #define BOOST_XXX_NULLPTR 0 #else #define BOOST_XXX_NULLPTR nullptr #endif where XXX is some local name for my own use. And then use BOOST_XXX_NULLPTR in places where a null pointer is needed. Would this be a candidate for a BOOST_NULLPTR macro in the config library instead ? Edward Diener

16 63

[iterator] UB when implicitly using default constructed counting_iterator<unsigned>
by Peter Sommerlad 07 Dec '12

07 Dec '12

Hi Jeffrey, hi all, I believe the usability of counting iterator could be improved, by value-initializing its Iterator type in the default constructor, because integral types won't be initialized by its default constructor. This can lead to hard to recognize user errors, e.g., when wrapping such a counting iterator with a filter iterator. counting_iterator is special in that sense, because to my understanding it is intended to adapt integral types to become iterators. And a default initialized scalar type, isn't. I suggest a one line change: counting_iterator() { } should become counting_iterator() : super_t(Incrementable()) { } The following example program shows the interesting UB, because the 3rd argument of make_filter_iterator, default constructs a counting_iterator<unsigned>(). Any thoughts? Objections? Teachings... Regards Peter. =====>8 #include <iostream> #include <boost/iterator/filter_iterator.hpp> #include <boost/iterator/counting_iterator.hpp> #include <algorithm> #include <iterator> #include <functional> struct is_prime{ bool operator()(unsigned int val) const { if (val < 2) return false; using std::placeholders::_1; auto ce=boost::make_counting_iterator(val); return ce==std::find_if_not(boost::make_counting_iterator(2u),ce, bind(std::modulus<unsigned>{},val,_1)); } }; int main(){ std::copy_n(boost::make_filter_iterator(is_prime{},boost::make_counting_iterator(1u) // if the following line is omitted we have undefined behavior, because of uninitialized unsigned value // ,boost::make_counting_iterator(std::numeric_limits<unsigned>::max()) // must be different from above value ),40,std::ostream_iterator<unsigned>{std::cout,", "}); } =====8< -- Prof. Peter Sommerlad Institut für Software: Bessere Software - Einfach, Schneller! HSR Hochschule für Technik Rapperswil Oberseestr 10, Postfach 1475, CH-8640 Rapperswil http://ifs.hsr.ch http://cute-test.com http://linticator.com http://includator.com tel:+41 55 222 49 84 == mobile:+41 79 432 23 32 fax:+41 55 222 46 29 == mailto:peter.sommerlad@hsr.ch

3 2

[compond_file_binary] Gauging interest in a possible library submission.
by А В 06 Dec '12

06 Dec '12

Hi, all. Is there any interest in a cross-platform C++ library which allows to create/read/write binary compound files? Briefly, compound file is filesystem for storing files and directories within a single file on a disk. Initially compound file format is developed by Microsoft and now is the part of Microsoft's Open Specifications Documentation. Compound files are used across various platforms and applications, and not restricted by some specific domain. In general, any application can store information in such a way. I've found on the Internet interest in such library and decided to implement it. Additional information can be found here: Article on the Wikipedia: http://en.wikipedia.org/wiki/Compound_File_Binary_Format Benefits of Compound Files: http://msdn.microsoft.com/en-us/library/windows/desktop/aa378938(v=vs.85).a… [MS-CFB] Open specification for compound files: http://msdn.microsoft.com/en-us/library/dd942138.aspx Regards, Alexander Voitenko.

11 26

[BGL] status of maximum adjacency search
by Fernando Vilas 03 Dec '12

03 Dec '12

Hi, What remains to get ticket 6780 ready to commit? -- Thanks, Fernando Vilas fvilas(a)iname.com

2 2

Re: [boost] [locale] [filesystem] Windows local 8 bit encoding
by Thiel, Bjoern 30 Nov '12

30 Nov '12

Hi Artyom, > Currently win32 API supports only UTF-8 encodings, so you need to one of: > > - compile with ICU > - select std backend (because the default without ICU on windows is win32) > - disable win32 backend (in build options) so only std backend would be used. But you should note that under > Windows only MSVC has std backend support, for gcc and ANSI encodings you need ICU, Is there reason why win32 and std backend behave differently here? Using std locale get_system_locale() method works for code pages of the form 'windows-XXX'. Others e.g. 'Shift_JIS' should fail. And if you want the CURRENT locale on Microsoft Windows, I simply can't see how to get that. But why not add generator.generate( void ) giving exactly that. Best regards Bjoern.

5 7

[mpl] Determining when a type is a placeholder expression
by Edward Diener 30 Nov '12

30 Nov '12

Is there any way to determine when a type is an MPL placeholder expression ? I can determine whether a type is a metafunction class ( it has a class template called 'apply' ), but I can't think of any sure way to determine whether or not a type is a placeholder expression. Ideally if a type in one of my templates is an MPL lambda expression ( its either a metafunction class or placeholder expression ) I want to invoke it with some compile-time data, otherwise I want to do something else with that type. Of course a less elegant solution is to have another template boost::mpl::bool_ parameter telling which it is but I was hoping to avoid it if I can figure it out myself.

2 1

i am not able to login in to the Trac
by Nilesh Raghuvanshi 29 Nov '12

29 Nov '12

Hi, please help me out with this. how to get to know my username and password. Thanks & regards Nileshkumar K R

3 3

[context] guarded_stack_allocator
by Jeremiah Willcock 29 Nov '12

29 Nov '12

I don't know if I've missed an earlier mailing list post on this topic, but why was guarded_stack_allocator removed from Boost.Context in the trunk? What should be used instead? The simple_stack_allocator that is an example, or some other general-purpose (no-guard-page) allocation function? -- Jeremiah Willcock

2 1

[result_of] fails with clan (C++11)
by Oliver Kowalke 29 Nov '12

29 Nov '12

Hello, clang (c++11 support) fails on code like: BOOST_STATIC_ASSERT(( is_same< void, typename result_of< Fn() >::type >::value)); with error: no type named 'type' in 'boost::result_of<void (&())(X &)>' is_same< void, typename result_of< Fn() >::type >::value)); ~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~ ../boost/static_assert.hpp:48:50: note: expanded from macro 'BOOST_STATIC_ASSERT' # define BOOST_STATIC_ASSERT( B ) static_assert(B, #B) ^ Do you know why it fails? (other compilers like gcc, intel, msvc compile the code) regards, Oliver

6 19

boost::shared_ptr and serialization
by Klaus - Peter Weber 28 Nov '12

28 Nov '12

Hi, I am trapped in an assertion from boost::serialization and maybe someone here has an idea how to solve this. I am using Visual Studio 2008 with Boost 1.49.0 having a simple class in a shared library like : class CTest : public ICTest { friend class boost::serialization::access; template<class Archive> void serialize( Archive & ar, const unsigned int version) { ar & boost::serialization::base_object<ICTest>(*this); ar & i; }; public : CTest::CTest():i(0){}; void setI( int _i){ i = _i;}; int getI( void){ return i;}; int i; }; and an interface class like : class ICTest { friend class boost::serialization::access; template<class Archive> void serialize( Archive & ar, const unsigned int version){}; public : virtual ~ICTest(){}; virtual void setI( int _i) = 0; virtual int getI( void) = 0; }; For the CTest class is not exported and not accessible directly from out of the shared lib, an interface is provided : MY_DLL_EXPORT_MACRO ICTest* CreateCTestClassInstance( void) { return new CTest(); } typedef boost::shared_ptr<ICTest> pICTest; Instantiating the interface in my program and using CTest class instance: pICTest p1( CreateCTestClassInstance()); p1->setI( 1); works fine, so far so good. A Problem occures when I try to serialize CTest class like : { std::ofstream ofs( fileNameTXT); boost::archive::text_oarchive ar( ofs); ar & p1; // causes an assertion } This results in an assertion (->BOOST_ASSERT(false);) in basic_serializer_map.cpp in line 102. It seems to me, there is a problem with finding the derived class in the basic_serializer_map. Instantiation of CTest class directly terminates with no error, which means, the serialization basically works correctly. Does anyone have an idea how to serialize an interface class correctly ? Peter

2 1

Date_Time : Error in time_duration.hpp
by GAURAV GUPTA 28 Nov '12

28 Nov '12

Hello, I have encountered some errors in Boost, while running some static analyzer tool. It is reported in boost/date_time/time_duration.hpp The error is: *boost::date_time::time_duration has user-written copy constructor but no corresponding user-written assignment operator.* *Is it valid to apply the following patch.* diff -Naur a/boost/date_time/time_duration.hpp b/boost/date_time/time_duration.hpp --- a/boost/date_time/time_duration.hpp 2012-10-11 00:35:03.000000000 +0530 +++ b/boost/date_time/time_duration.hpp 2012-11-26 18:29:16.000000000 +0530 @@ -251,6 +251,9 @@ return ticks_; } + private: + time_duration &operator=(const time_duration<T, rep_type>& other); + protected: explicit time_duration(impl_type in) : ticks_(in) {} impl_type ticks_; * * -- Regards, Gaurav

3 5

Algorithm : Error in find_iterator.hpp
by GAURAV GUPTA 28 Nov '12

28 Nov '12

Hello, I have encountered some errors in Boost, while running some static analyzer tool. It is reported in boost/algorithm/string/find_iterator.hpp The error is: *boost::date_time::time_duration has user-written copy constructor but no corresponding user-written assignment operator.* *Is it valid to apply the following patch.* diff -Naur a/boost/algorithm/string/find_iterator.hpp b/boost/algorithm/string/find_iterator.hpp --- a/boost/algorithm/string/find_iterator.hpp 2011-01-11 01:06:38.000000000 +0530 +++ b/boost/algorithm/string/find_iterator.hpp 2012-11-26 18:19:39.000000000 +0530 @@ -119,6 +119,9 @@ increment(); } + private: + find_iterator & operator=( const find_iterator& Other ); + private: // iterator operations @@ -288,6 +291,8 @@ increment(); } } + private: + split_iterator & operator=( const split_iterator& Other ); private: -- Regards, Gaurav

2 2

More on augmented trees
by Phil Endecott 28 Nov '12

28 Nov '12

Dear All, A while ago I posted a question about augmented trees: http://thread.gmane.org/gmane.comp.lib.boost.devel/235004 There has also been other discussion recently in this thread: http://thread.gmane.org/gmane.comp.lib.boost.devel/236103 Unfortunately I have been manically bug-hunting for the last few weeks [*] and wasn't able to follow-up properly until now. Here are my thoughts: I'm aware of 3 applications for augmented trees: - O(log N) indexing, insertion and deletion; "best of list and vector" (i.e. Countertree). - Similar where the "value" of each node is variable, so one can accumulate over any range in O(log N) time (i.e. stl_ext_adv). - Interval trees. In the first two cases, the augmented value is the sum of the augmented values in the sub-nodes. In the last case, it's the maximum of them. Is anyone aware of any other applications that are not not very similar to those, e.g. where the augmentation is some other function of the sub-nodes? Question: with only three (or two, if the first is considered a special case of the second) different kinds of augmentation, is it worthwhile to try to distil out a generic augmented tree? Here is an interesting augmented tree implementation that attempts to be generic: http://kaba.hilvi.org/pastel/pastel/sys/redblacktree.htm This seems to work by exposing the tree structure in the iterator (i.e. the iterator has parent(), left() and right() methods that return other iterators), and by requiring a Customization class that is called to updated augmented data in a node when its children change. This looks to me to be a sensible approach, but I'm still not sure that it's better than just copy-and-paste when there are only two (or three) useful ways to apply it. Thoughts anyone? Regards, Phil. [*] My recent bug-hunting has really made me value the ease of working with open-source code like Boost. What might take 5 minutes with grep instead takes weeks of back-and-forth with "technical support" (or reverse-engineering with a disassembler) - literally 3 orders of magnitude less efficient.

2 1

[generic] possible new syntax
by Lorenzo Caminiti 27 Nov '12

27 Nov '12

Hello all, I have been in contact with Matt Calabrese to design a new syntax for Boost.Generic that leverages the preprocessor EDSL techniques introduced by Boost.Contract. See the "This Library" column in the links below for a side-by-side comparison with the existing Boost.Generic syntax and the N2914 syntax. *** It's important to finalize the syntax before I start implementing the macros that will parse it: Please tell me what you think of the new syntax and ask questions if you have any. *** Container concept: http://contractpp.svn.sourceforge.net/viewvc/contractpp/branches/n2914_conc… EmplacementContainer concept: http://contractpp.svn.sourceforge.net/viewvc/contractpp/branches/n2914_conc… Allocator concept: http://contractpp.svn.sourceforge.net/viewvc/contractpp/branches/n2914_conc… All N2914 concepts (that's a lot!): http://contractpp.svn.sourceforge.net/viewvc/contractpp/branches/n2914_conc… Code, notes, to-dos, etc: http://contractpp.svn.sourceforge.net/viewvc/contractpp/branches/n2914_conc… NOTES * I'm assuming the library will be renamed Boost.Concepts so I'm using BOOST_CONCEPTS_... and boost::concepts::... but Matt and I have not agreed on this. * Some extra commas `,` might be needed at the end of each function and axiom definition. In this case, it might also be possible to use { ... } instead of ( ... ) around function definitions (but not for axiom definitions) at the cost of users handling unwrapped commas in function definitions using BOOST_IDENTITY_TYPE or similar. * I'm assuming a C++11 preprocessor that can correctly handle empty macro parameters (workarounds will be provided when that's not the case). Thanks, --Lorenzo

1 0

boost::chrono problem with gcc-4.6.3
by Neo Apostol 27 Nov '12

27 Nov '12

Hello everyone. I use android-ndk (http://www.crystax.net/en/android/ndk/7) with boost-1.49. My code includes boost::chrono, and when I use gcc-4.4.3 everything goes fine, but when I swith on the gcc-4.6.3 (APP_USE_CPP0X := true) so than i get a strange mistake. C/C++ Problem 'u16string' in namespace 'std' does not name a type TestCore line 243, external location: /Users/user/Mobile/android-ndk-crystax/sources/boost/boost/ratio/ratio_io.hpp C/C++ Problem 'u16string' in namespace 'std' does not name a type TestCore line 242, external location: /Users/user/Mobile/android-ndk-crystax/sources/boost/boost/ratio/ratio_io.hpp C/C++ Problem 'u32string' in namespace 'std' does not name a type TestCore line 250, external location: /Users/user/Mobile/android-ndk-crystax/sources/boost/boost/ratio/ratio_io.hpp C/C++ Problem 'u32string' in namespace 'std' does not name a type TestCore line 249, external location: /Users/user/Mobile/android-ndk-crystax/sources/boost/boost/ratio/ratio_io.hpp C/C++ Problem 'u16string' in namespace 'std' does not name a type TestCore line 287, external location: /Users/user/Mobile/android-ndk-crystax/sources/boost/boost/ratio/ratio_io.hpp C/C++ Problem 'u16string' in namespace 'std' does not name a type TestCore line 286, external location: /Users/user/Mobile/android-ndk-crystax/sources/boost/boost/ratio/ratio_io.hpp C/C++ Problem 'u32string' in namespace 'std' does not name a type TestCore line 294, external location: /Users/user/Mobile/android-ndk-crystax/sources/boost/boost/ratio/ratio_io.hpp C/C++ Problem 'u32string' in namespace 'std' does not name a type TestCore line 293, external location: /Users/user/Mobile/android-ndk-crystax/sources/boost/boost/ratio/ratio_io.hpp C/C++ Problem 'u16string' in namespace 'std' does not name a type TestCore line 331, external location: /Users/user/Mobile/android-ndk-crystax/sources/boost/boost/ratio/ratio_io.hpp C/C++ Problem 'u16string' in namespace 'std' does not name a type TestCore line 330, external location: /Users/user/Mobile/android-ndk-crystax/sources/boost/boost/ratio/ratio_io.hpp C/C++ Problem 'u32string' in namespace 'std' does not name a type TestCore line 338, external location: /Users/user/Mobile/android-ndk-crystax/sources/boost/boost/ratio/ratio_io.hpp C/C++ Problem 'u32string' in namespace 'std' does not name a type TestCore line 337, external location: /Users/user/Mobile/android-ndk-crystax/sources/boost/boost/ratio/ratio_io.hpp C/C++ Problem 'u16string' in namespace 'std' does not name a type TestCore line 375, external location: /Users/user/Mobile/android-ndk-crystax/sources/boost/boost/ratio/ratio_io.hpp C/C++ Problem 'u16string' in namespace 'std' does not name a type TestCore line 374, external location: /Users/user/Mobile/android-ndk-crystax/sources/boost/boost/ratio/ratio_io.hpp ............................................... Does somebody can help me?

2 2

[range] iterator_range operators are too greedy
by Gennadiy Rozental 27 Nov '12

27 Nov '12

Hi, iterator_range operators are defined like this: template< class IteratorT, class ForwardRange > inline bool operator==( const ForwardRange& l, const iterator_range<IteratorT>& r ) { return boost::equal( l, r ); } These needs to be restricted with enable_if on type of first argument. I have a scenario where I want to define operator== for my own type and want to be able to use it with iterator_range as second argument. Above definition makes it impossible. Gennadiy

6 12

[boost::context] reusing stacks
by Valentin Milea 27 Nov '12

27 Nov '12

Hi, I'm working on a tiny coroutine library based on boost::context. For performance reasons I'd rather keep a pool of stacks instead allocating/deallocating every time. Is it legal to reuse a stack for a different context? namespace ctx = boost::context; ctx::fcontext_t fcm, *fc; void f1(intptr_t) { std::cout << "f1" << std::endl; ctx::jump_fcontext(fc, &fcm, 0); } void f2(intptr_t) { std::cout << "f2" << std::endl; ctx::jump_fcontext(fc, &fcm, 0); } int main(int argc, char * argv[]) { ctx::guarded_stack_allocator alloc; std::size_t size = ctx::guarded_stack_allocator::default_stacksize(); void *sp = alloc.allocate(size); fc = ctx::make_fcontext(sp, size, f1); std::cout << "main: jump 1" << std::endl; ctx::jump_fcontext(&fcm, fc, 0); fc = ctx::make_fcontext(sp, size, f2); // legal? std::cout << "main: jump 2" << std::endl; ctx::jump_fcontext(&fcm, fc, 0); std::cout << "main: done" << std::endl; return 0; }

2 6

[boost-mpl] -Wall -Werror issue
by Belcourt, Kenneth 27 Nov '12

27 Nov '12

Hi, This code generates sign / unsigned compare warning with -Wall, could this please be cleaned up? enum { n = # if defined(__EDG_VERSION__) aux::dependent_unsigned<T>::value > -1 # else sizeof(T) > -1 # endif }; It appears that sizeof(T) > -1 yields zero for EDG, Gcc and Clang so perhaps this is just older (unused) code? -- Noel Belcourt

2 4

[math] boost::math::isfinite fails with --fast-math
by Gaetano Mendola 26 Nov '12

26 Nov '12

Hi all, I'm wandering if this is to be expected, the following code fails if compiled with --fast-math: //==================================================== #include <boost/math/special_functions/fpclassify.hpp> int main() { const float a = 0.0f/0.0f; assert(not boost::math::isfinite(a)); } //==================================================== Regards Gaetano Mendola

6 13

gcc 4.4.3 + boost optional 1.40 crash
by Gaetano Mendola 26 Nov '12

26 Nov '12

Hi all, after banging my head for an entire day I come out with this test case showing a possible bug in gcc 4.4.3 or in boost optional, the test crashes with a pure virtual method called only if compiled only with -O1, -O2, -O3. The same code in another machine with gcc 4.7.2 and boost 1.49 works fine. Regards Gaetano Mendola #include <boost/optional.hpp> #include <boost/noncopyable.hpp> class B : boost::noncopyable { //if the noncopyable is removed works public: virtual size_t bar() const = 0; }; class D : public B { public: D() :theBar(foo(10)) { } virtual size_t bar() const { return theBar; } private: static size_t foo(const boost::optional<size_t> a) { if (a) { //if this is a.is_initialized() then it works return a.get(); } return 2; } const size_t theBar; }; class Foo { public: Foo(const B& b) :theBar(b.bar() * b.bar()) { } private: const size_t theBar; }; int main() { { //if this section is removed works D d; try { Foo myCompound(d); } catch(...) {} } { D d; try { Foo myCompound(d); } catch(...) {} } }

6 15

[mpi] New dedicated mailing list for Boost.MPI discussions
by Matthias Troyer 25 Nov '12

25 Nov '12

Dear all, We have created a new sub list boost-mpi(a)lists.boost.org for discussion of Boost.MPI development. Those interested can visit http://lists.boost.org/mailman/listinfo.cgi/boost-mpi to sign up. Best regards Matthias

2 2

[Numeric Conversion] Documentation Notes/Questions
by Dave Abrahams 25 Nov '12

25 Nov '12

* First thing to note: the documentation makes this library less approachable than it could be. In order to even begin, one has to bury onesself in terminology (the "Definitions" section). A super-quick "hello, world" example and a very short tutorial at the beginning would help a *lot*. numeric_cast is arguably the most generally-useful interface of the whole library and yet it's not even discussed until the end of the docs. * It's not clear what the purpose of abt(x) is. In expressions, "x" usually means its value. When you introduce a mechanism like this, it would be a good idea to explain why it's needed. Most places, the use of "abstract" just seems to complicate things: "A ulp is a quantity whose abstract magnitude" what's wrong with "A ulp is a quantity whose magnitude" ?? The end of the section on "Range and Precision" begins to explain why you want "abstract," but it takes the reader a long time to get to it. * are next() and prev() always well-defined? Seems to me that an unlimited precision rational number type might not have them. Is that type not numeric? * How do size, width, and density relate to unlimited precision rationals? I imagine: size = infinity width = infinity density = ? * This is slightly ambiguous: "This definition allows for a concise definition of subranged as given in the last section." "final section" would be clearer. A link would help too. * This is unclear: "Abstract intervals are easier to compare and overlap since only boundary values need to be considered." an example would help. How can one kind of thing be "easier to overlap" than another? * Precision has a very non-generic description, being different for types with density 1 and other types. It's hard to see what use such a concept has, and as far as Google can tell it is not used anywhere outside the Definitions section * Description of unsigned types, I think, is wrong: Notice that a numeric type, such as a C++ unsigned type, can define that any V does not overflow by always representing not V itself but the abstract value U = [ V % (abt(h)+1) ], which is always in range. Seems to me that the abstract values represented by an unsigned integer type are not the set of whole numbers, but the set of whole numbers modulo whatever-the-max+1-is. That's a well-defined mathematical abstraction, isn't it? Is there a problem with that, such as multiplication not working properly (I don't think so)? * There seems to be a contradiction here: If V >= abt(l) and V <= abt(h), V is representable (can be represented) in the type T ... Given an abstract value V represented in the type T as v, the roundoff error of the representation is the abstract difference: ( abt(v)-V). If V is not representable in type T, can you write formulae using its representation in type T? Given what I read later, maybe you should have just said "exactly representable" in the first phrase. * s/at most/less than/?: Because a correctly rounded representation is always one of adjacents of the abstract value being represented, the roundoff is guaranteed to be at most 1ulp. * s/cannot be represented/cannot be exactly represented/ ?: The integer number -1 can be exactly represented in Int, Real and Whole, but cannot be represented in Cardinal, yielding negative overflow. * Uh-oh: Floating to Floating conversions are defined only if N is representable; if it is not, the conversion has undefined behavior. in many places you've used "representable" to mean "exactly representable," but I can't believe you mean that here; it would imply most double=>float conversions have undefined behavior. What does this mean, anyway? If an abstract value can be "inexactly representable," aren't all abstract values representable if there's at least one abstract value that's exactly representable? Just convert to that and you're done. I think you need to give some serious thought to the definition of "representable." * s/then/so/: R(X) & R(Y) == R(X), then X->Y is not subranged. Thus, all values of type X are representable in the type Y. (b) Y->X: R(Y) & R(X) == R(Y), then Y->X is not subranged. Thus, all * What's the difference between a policy and a "parameter that defines the conversion" in It can optionally take some policies which can be used to customize its behavior. The Traits parameter is not a policy but the parameter that defines the conversion. ?? -- Dave Abrahams BoostPro Computing Software Development Training http://www.boostpro.com Clang/LLVM/EDG Compilers C++ Boost

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[Review] Review results for Coroutines
by Hartmut Kaiser 24 Nov '12

24 Nov '12

All, The review for the Coroutines library written by Oliver Kowalke started September 3rd 2012, and ended on September 12th 2012. I counted 7 votes, none of which were NO. All authors votes YES, some made additional requests. Overall, the verdict of the community was clear: Oliver Kowalke's Coroutines library is ACCEPTED The discussion was lively and it touched on several points. Design ------ The Coroutines library offers enormous potential for programming regimes such as communications software and embedded systems design. Oliver selected a sensible granularity for his design. This granularity allows for fine-tuning the implementations of cooperative scheduling mechanisms while avoiding the prohibitively heavy weight of preemptive scheduling that is found in POSIX and often in implementations of the C++11 thread support library. In particular, the separation of Coroutines from Context allows for porting to other systems with minimal effort and maximum reliability and code re-use. Some suggestion related to the API have been made during the review, most of which (if not all) have already been addressed. Oliver has a full list of things and works on integrating the suggestions. Here is a short list: - allow to specify the allocator to use for memory allocations inside the library - remove 'self' pointer and replace with TLS - add symmetric coroutines API - better support for generator functionality Naming ------ Some of the people participating in the discussions suggested not to use the abbreviated 'namespace coro', but to use the full 'namespace coroutines' instead. This again is not a precondition for acceptance. Documentation ------------- The consensus of almost everybody referring to the documentation was that it is terse but readable and sufficient. People suggested to integrate the docs of the old Coroutines library (written as an GSoC project by Giovanni P. Deretta) into the documentation of the reviewed library. I would like to thank all who participated in the discussions. Regards Hartmut --------------- http://www.cct.lsu.edu/~hkaiser http://stellar.cct.lsu.edu http://boost-spirit.com

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Re: [boost] Countertree
by Leo Goodstadt 23 Nov '12

23 Nov '12

> On Tue, 20 Nov 2012, Vadim Stadnik <vadimstdk(a)gmail.com> wrote: > > On Mon, Nov 19, 2012 at 9:02 PM, Leo Goodstadt <leo.goodstadt(a)llew.org.uk>wrote: > > 1) For counter trees, the median is just the N/2-th value in the > > counter tree, where K is the size of the tree. > > The Nth-percentile can be calculated similarly. > > A rolling median with a fixed size window requires there to be an > > insertion and deletion for each (most!) new value, so I am guessing > > it should run in O(N log K) time, where N = size of data, K = size of > > window > > > > IIUC, it is better to avoid modifying original data (size N), the rolling > window of size K can be represented by a multiset based on an augmented > tree. This method guarantees complexity of obtaining 1st median value for > O(K log K) operations, which is the cost of construction of the rolling > window, every subsequent median value can be obtained for O(log K) > operations, when the window rolls. This approach should be more efficient. > Oops. Careless editing made me mix up my Ks and Ns, hopeless confusing everyone. So given a large data set of size N and we want to calculate medians across a rolling window of size K, we only need to create a counter tree of size K (the window size). The median is the K/2 value in the tree. As you point out, the entire operation runs in O(N log K) time. All sensible approaches to calculating medians I can think of take O(N log K) time. The question comes down to what the constants are. The great advantage of a counter tree is that we are not limited to medians (the 50%ile value). We can collect for example, the values at 25%, 50%, and, 75%, and so on, at only marginally extra cost. I presume that most of the cost lies in balancing the tree after insertions/deletions and updating the counters. The only shortcut is the trivial optimisation that if the value entering the window is the same as the one being removed at the other end, then the median obviously stays the same. Leo

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[coroutine] update for intel/clang
by Oliver Kowalke 23 Nov '12

23 Nov '12

The lib compiles with gcc, intel, clang (bug fixed), msvc and mingw (statically linked) on Windows. The fixed version of boost.coroutine is available at: http://ok73.funpic.de/boost-coroutine.zip. The documentation is updated too: http://ok73.funpic.de/boost/libs/coroutine/doc/html/index.html Oliver

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Re: [boost] [website] bcp link broken
by Brian Wood 22 Nov '12

22 Nov '12

>>> bcp. Get taken nowhere. Any clues? TIA, >> >> Some googling found the page[*]. There, I read this: >> >> Copyright ? 2209 John Maddock >> >> Year 2209?! Great scott!!! Doc Emmett just called. He wants his DeLorean >> back. ;-) > > DeLorean? Man that's so last millenium :) > Maybe some are noticing a back to the future element in C++? -- Brian Ebenezer Enterprises http://webEbenezer.net (651) 251-9384

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[preprocessor] Maybe a improvement of BOOST_PP_IS_EMPTY
by Zhenghui Zhou 22 Nov '12

22 Nov '12

As I known, the undocument interface BOOST_PP_IS_EMPTY is not a general implementation to condider emptiness. There is a undefined behaviours when token concatenation return a invalid preprocessing token. Particularly, gcc restriction reports error. For example: #include <boost/preprocessor/ facilities/is_empty.hpp> BOOST_PP_IS_EMPTY() /* result: 1 */ BOOST_PP_IS_EMPTY(a) /* result: 0 */ BOOST_PP_IS_EMPTY(+a) /* error report here, for '+' cannot be pasted */ Here is a work around, it hasnot been tested enough, but does do under gcc. #define MY_IS_EMPTY(a) BOOST_PP_EQUAL(BOOST_PP_SEQ_ SIZE(MY_IS_EMPTY_II(MY_IS_EMPTY_I(a))), 2) #define MY_IS_EMPTY_I(a) (BOOST_PP_CAT(MY_IS_EMPTY_I_, BOOST_PP_SEQ_SIZE(a))) ) #define MY_IS_EMPTY_I_0 MY_IS_EMPTY_I_HELPER BOOST_PP_LPAREN() #define MY_IS_EMPTY_I_HELPER(a) )a( /* when a is empty, my may get more sequence elements of boost proprocessor */ #define MY_IS_EMPTY_II(a) BOOST_PP_CAT(MY_IS_EMPTY_II_, BOOST_PP_SEQ_SIZE(a)) ) #define MY_IS_EMPTY_II_1 ( #define MY_IS_EMPTY_II_2 ()( It uses a intermadiate result of BOOST_PP_SEQ_SIZE with wrong parameters, as: BOOST_PP_SEQ_SIZE(a) => 0 a ... I think it maybe better to allow any concatenation tokens in the language itselft. It's hard to avoid such thing when taking the preprocessor as a MPL. I just reported it on comp.std.c, https://groups.google.com/forum/#!topic/comp.std.c/7rgt8k6ILMM. There are more things and problems I did and I met. Hope for more response.

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[website] bcp link broken
by Eric Niebler 22 Nov '12

22 Nov '12

Go here: <http://www.boost.org/doc/tools.html>. Click on the link to bcp. Get taken nowhere. Any clues? TIA, -- Eric Niebler BoostPro Computing http://www.boostpro.com

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[dynamic_bitset] expression template?
by Ben Coates 21 Nov '12

21 Nov '12

dynamic_bitset currently allocates temporary vectors for most operations, and all the allocating and deallocating can easily dominate the running time for a program that makes heavy use of them. You can work around some of it with careful use of named temporaries around loops but some operations like intersection of 3 sets ( (a & b & c).any() ) result in a lot of unwanted copies and allocations. I've had good results converting it to use expression templates for intermediary operations, with the outcome of being able to do arbitrary non-resizing operations without allocating. Is there any interest in changing the boost version to do this?

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Should the clang, c++11 and libstdc++ configuration supported?
by Vicente J. Botet Escriba 21 Nov '12

21 Nov '12

Hi, clang compiler is not delivered with a C++11 standard library. When compiling on c++11 mode, some boost libraries (in particular, Boost.Thread, Boost.SmartPtr, Boost.Test) are expecting to have a C++11 standard library. This mean that the user needs to install the latest version of libc++. Could we state clearly in the release notes if the combination clang+ -std=c++11 + libstdc++ is not supported. Otherwise these libraries should update their code so that the user can use this combination. Best, Vicente

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[stl_ext_adv] comparison with Boost.Container and string algorithms
by Vadim Stadnik 21 Nov '12

21 Nov '12

Hi all, In response to the previously made suggestion, I have added to the documentation the comparison of new proposed STL containers with Boost.Container. Please let me know if some of my statements concerning Boost.Container are incorrect, I will update the documentation. >From a user perspective an augmented array based B+ tree of the new library can be regarded as a segmented vector that offers several more efficient operations than std::vector: logarithmic time insertion, erasure, splice and split. One such data structure can support interfaces of all C++03 standard sequences and associative containers. This is why new containers offer a higher level of uniformity and generalization of the C++ standard containers. Unlike std::vector, the new array based containers do not have the problem of exponential storage growth and manual shrinking storage to the optimal capacity. The comparison section also includes simple tests of performance. One test shows the advantage of the wide set of efficient operations of new containers. None of the C++ standard and Boost containers can outperform new containers in the test with just two operations: move an iterator to a specified position and then insert a new element. The other test shows that new containers have good locality of reference. In sequential processing they perform much better than containers using dynamically allocated data structures. String algorithms The new sequence container that implements the union of interfaces of std::vector, std::list and std::deque is particularly beneficial for string algorithms. A container, such as std_ext_adv::sequence<char>, efficiently supports all main editing string operations: cut, copy, paste, delete, find, replace, etc. In terms of computational complexity this new container provides general and equally efficient support for both copy and move semantics operations. The move semantics functions splice() and split() can be used to replace inefficient copy semantics functions insert() and erase() to achieve significant performance improvements. The examples section and code shows how to concatenate two strings and extract a sub-string in logarithmic time using the move semantics functions. These operations do not require that user algorithms count moved characters. This functionality and efficiency are not possible with linked lists and basic search trees. The efficient calculation of statistical parameters and numerical integration in logarithmic time are the other practically important applications of the new containers. They are discussed in the examples section. Project (source code and documentation): https://github.com/vstadnik/stl_ext_adv_review Documentation: http://dl.dropbox.com/u/51041088/stl_ext_adv_review/doc/index.html Regards, Vadim Stadnik

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Re: [boost] [Boost-build] [VxWorks] Updating boost/config/platform/vxworks.hpp for VxWorks 6.9
by Vicente J. Botet Escriba 20 Nov '12

20 Nov '12

Le 20/11/12 15:30, Brockamp, Peter a écrit : > Hello everybody, > > I'm new to the Boost.Build mailing list, so please forgive me any newbie > mistakes. I hope this is the right place for my post, if not please > redirect me to where it belongs! > I'm replied to the boost dev ML as most of the patches concern Boost.Config. > OK, some time ago I had to realize that the platform configuration for > VxWorks boost/config/platform/vxworks.hpp appears to be badly outdated > and doesn't work with the actual version 6.9. I started to modify this > platform header and after a while managed to get Boost compile and run > under VxWorks 6.9, at least as far as we use it here today. I could > offer to the community to update the existing header if this is desired > (I suppose it is). If so should I post the source code here or how to > proceed? Yep, a newbie question. You can start by creating a ticket on the Trac system https://svn.boost.org/trac/boost/newticket. You could add a patch associated with the ticket. > > My modifications surely aren't perfect/complete but it might be a fresh > start for this OS: > > - I have only tested it under RTP (Real Time Process) of VxWorks, not > DKM (Downloadable Kernel Module), due to lack of time. DKM has many > limitations compared to RTP, so this might cause problems! > > - Equally, due to time constraints, I tested GCC only, not the > diab-compiler, as we don't use it here. Same as above applies here, > problems might arise and I could not guarantee I might be able to fix > them. > > - And I tested x86 only, as we actually don't develop for ARM, etc. > > - I could test with V6.9 only, as we are not using the prior versions, > so maybe there will be other problems yet unknown. But at least I could > confirm that it is impossible to get Boost running under early versions > of VxWorks (V5.x and older). These versions are lacking a couple of > library functions required by Boost, they come with a library which is > partially non-ANSI-conforming (especially the STL) and the compiler (GCC > 2.96) is outdated beyond believe and lacks some functionality (mainly > template stuff) needed by Boost. So some OS-version checking scheme > would have to be added to vxworks.hpp, bailing out in case of obsolete, > unsupported versions. > > - A support guy from WRS (Wind River System) mentioned that they are > thinking of including Boost into their OS, so they might do some > adaption work in the future. But until now it doesn't appear to me > there's much activity from WRS, that's why I decided to offer what I > have done so far. > > - When compiling Boost for VxWorks I didn't use the build-system, as > VxWorks does a cross compile for the destination platform and I didn't > manage to figure out how to auto build this. Instead I manually pulled > all of Boost's files into a Workbench Project (Workbench is the eclipse > based IDE of VxWorks). So there would be some work left to get this up & > running as well. > > - My work is based mainly on modifying and supplementing most parts of > vxworks.hpp. Anyway, during the tests I did I stumbled upon some > problems in other files, e. g. caused by missing #ifdef's for VxWorks, > and even errors in a few of Boost's files, which I fixed as well. Should > all these fixes be posted here, or what's the right way to do it? > > > So, if you see some potential use in what I have done, despite the > incompleteness pictured above, please someone responsible mail me with > further instructions. > Best, Vicente

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Boost.Thread 1.52 vs 1.51 - g++ 4.7.2
by Jose 20 Nov '12

20 Nov '12

When including thread.hpp (1.52) I get the error below. Same setup but Boost 1.51 works ok. Does anybody know what is the issue ? thanks # g++ -c test.cpp In file included from /usr/include/boost/thread.hpp:24:0, from test.cpp:1: /usr/include/boost/thread/future.hpp:139:26: error: expected ‘;’ at end of member declaration /usr/include/boost/thread/future.hpp:139:32: error: ‘BOOST_THREAD_NOEXCEPT_OR_THROW’ does not name a type /usr/include/boost/thread/future.hpp:139:19: error: looser throw specifier for ‘virtual const char* boost::future_error::what() const’ In file included from /usr/include/boost/thread/exceptions.hpp:21:0, from /usr/include/boost/thread/pthread/thread_data.hpp:10, from /usr/include/boost/thread/thread.hpp:17, from /usr/include/boost/thread.hpp:13, from test.cpp:1: /usr/lib/gcc/x86_64-redhat-linux/4.7.2/../../../../include/c++/4.7.2/stdexcept:70:5: error: overriding ‘virtual const char* std::logic_error::what() const throw ()’

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Graph Algorithm Advice
by J Birch 20 Nov '12

20 Nov '12

This isn't a Boost Graph problem per se, just a graph algorithm question. Let's say I have the following graph: I want to represent this graph in a certain way. In the small legend box above, there are 2 versions of a correct answer. I want to print out each vertex followed by it's immediate adjacent vertex. If it has more than one, then each path from that point should be wrapped in a '()'. Currently, I am using the Ruby RGL package and have tried both a directed and an undirected graph using a depth first search traversal, and have yet to hit on an algorithm that takes every edge case. Anyone out there have some pointers on how to do this? Thanks! Birch

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Failing to build Boost.Test library using Clang 3.1 on Netbeans
by Paul A. Bristow 20 Nov '12

20 Nov '12

Target: i686-w64-mingw32 Thread model: posix) (This is Ruben's mingw64 build) on Netbeans 7.2 on Windows 7. The compilation stage goes OK (but with many warnings In file included from i:/boost-trunk/libs/test/src/test_tools.cpp:16: In file included from i:/boost-trunk\boost/test/impl/test_tools.ipp:23: i:/boost-trunk\boost/test/tree/test_unit.hpp:164:7: warning: 'dllexport' attribute only applies to variables and functions class BOOST_TEST_DECL master_test_suite_t : public test_suite { ^ i:/boost-trunk\boost/test/detail/config.hpp:106:29: note: expanded from macro 'BOOST_TEST_DECL' # define BOOST_TEST_DECL BOOST_SYMBOL_EXPORT ^ i:/boost-trunk\boost/config/platform/win32.hpp:30:42: note: expanded from macro 'BOOST_SYMBOL_EXPORT' # define BOOST_SYMBOL_EXPORT __declspec(dllexport) ^ <built-in>:150:38: note: expanded from macro '__declspec' #define __declspec(a) __attribute__((a)) but the link stage to build the library fails with many Cannot export boost::test_tools::tt_detail::check_impl(boost::test_tools::predicate_result const&, boost::unit_test::lazy_ostream const&, boost::unit_test::basic_cstring<char const>, unsigned int, boost::test_tools::tt_detail::tool_level, boost::test_tools::tt_detail::check_type, unsigned int, ...): symbol not found (full output window message attached). I have also failed to build using bjam (missing <cstddef> so missing the right stdlib?) and I wonder if both these are connected with lack of a suitable boost/config.hpp which caters for Clang *on this configuration*. Where would/should __clang__ be defined in order to select this compiler? My user-config.jam contains (in an attempt to cure ) # Clang compiler using mingw32 dw2 Ruben's release. using clang : 3.1 : "C:/mingw32-dw2/bin/clang++.exe" : <cxxflags>-v <cxxflags>-std="c++11" <cflags>-nostdinc # Do not include MSVC C headers. #<cflag>-c-include-dirs=??? <cxxflags>-nostdinc++ # Do not include MSVC C++ headers. # Use mingw-dw2 for includes <cxxflags>-cxx-include-arch="C:/mingw32-dw2/i686-w64-mingw32" <cxxflags>-cxx-include-32bit-dir=32 <cxxflags>-cxx-include-root="C:/mingw32-dw2/include/c++/4.6.3" <cxxflags>-stdlib=libc++ #<compileflags>-std=gnu++11 #<define>BOOST_STDLIB_CONFIG="i:/boost-trunk/boost/config/stdlib/libstdcpp3.hpp" <linkflags>-stdlib=libc++ ; Any views on my woes? Paul --- Paul A. Bristow, Prizet Farmhouse, Kendal LA8 8AB UK +44 1539 561830 07714330204 pbristow(a)hetp.u-net.com

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Re: [boost] Graph Algorithm Advice
by J Birch 19 Nov '12

19 Nov '12

Sorry, I had pasted it in the client. it is attached now. Thanks! Birch On Nov 19, 2012, at 5:03 PM, Jeremiah Willcock <jewillco(a)osl.iu.edu> wrote: > (off list) > > I don't see your attachment on there. > > -- Jeremiah Willcock > > On Mon, 19 Nov 2012, J Birch wrote: > >> This isn't a Boost Graph problem per se, just a graph algorithm question. Let's say I have the following graph: >> >> >> >> I want to represent this graph in a certain way. In the small legend box above, there are 2 versions of a correct answer. I want to print out each vertex followed by it's immediate adjacent vertex. If it has more than one, then each path from that point should be wrapped in a '()'. Currently, I am using the Ruby RGL package and have tried both a directed and an undirected graph using a depth first search traversal, and have yet to hit on an algorithm that takes every edge case. >> >> Anyone out there have some pointers on how to do this? >> >> Thanks! >> Birch >> >> _______________________________________________ >> Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost >>

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Re: [boost] Countertree
by Leo Goodstadt 19 Nov '12

19 Nov '12

On 17 November 2012 19:44, Francisco Jos? Tapia <fjtapia(a)gmail.com> wrote: > 2012/11/16 Vadim Stadnik <vadimstdk(a)gmail.com> > > On Sat, Nov 17, 2012 at 4:25 AM, Leo Goodstadt <leo.goodstadt(a)llew.org.uk wrote: > > > > > > Project location ( zip file with code and documentation) : > > > > https://dl.dropbox.com/u/8437476/works/countertree_code_doc.zip > > > > > > > > Quick view of documentation with code download : > > > > https://dl.dropbox.com/u/8437476/works/countertree/index.html > > > > > > > > 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 > > > > > > > > > Among other things, countertree would allow the boost Statistical > > > Accumulators Library to support rolling median and rolling quantiles > > > efficiently. This would be very useful. > > > > > > I had previously had to hack the tree class in the Policy-Based Data > > > Structures part of the gnu c++ library. > > > (see http://gcc.gnu.org/onlinedocs/libstdc++/ext/pb_ds/tree_order_statistics_nod… ) > > As far as I know, this support is not yet available in countertree project, > > although this is possible in principle. > > About the compatibility with the boost Statistical Accumulators Library, I > didn't thought about it, but it would be useful. I will try to implement, > but I need to examine in deep for to provide you a well founded opinion. > 1) For counter trees, the median is just the N/2-th value in the counter tree, where K is the size of the tree. The Nth-percentile can be calculated similarly. A rolling median with a fixed size window requires there to be an insertion and deletion for each (most!) new value, so I am guessing it should run in O(N log K) time, where N = size of data, K = size of window 2) The alternative is to use two multisets corresponding to values smaller and larger than the current median (or the Nth percentile). This should also have O(N log K) complexity. 3) With the special case where the data consists of integers in a fixed range, we can use a segment tree where the complexity would be O(N log R) where R = the size of the fixed range of data values. This can result in considerable speed ups. The best bit about counter trees are their flexibility, we can calculate multiple Nth-percentiles at the same time (e.g. all the quartiles). As to the actual rather than theoretical speed, I think we need bench-marking.... Leo

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[boostcon12]Trouble with tuples very compiler dependent
by Larry Evans 19 Nov '12

19 Nov '12

This thread is a continuation of that started here: http://article.gmane.org/gmane.comp.lib.boost.devel/235427 It's been renamed because the new name is more topical. The tree_builder benchmarks mentioned here: http://article.gmane.org/gmane.comp.lib.boost.devel/235386 were refactored into: tuple_benchmark.tree_builder.cpp tuple_impl.bcon12_horizontal.hpp tuple_impl.bcon12_vertical.hpp and various other .hpp files. The benchmark was run as shown in the attached filt.compilation. The output after line: :filt_dr= shows with compiler=gcc4_8, the bcon12_horizontal implementation is slower than the bcon12_vertical. This agrees, at least qualitatively, with the page 12 bar chart from Eric's boostcon12 pdf file: trouble_with_tuples.pdf downloadable from here: https://github.com/boostcon/cppnow_presentations_2012/zipball/master and in the mon directory. The variadic bar in the pag12 bar chart corresponds to the: tuple_impl.bcon12_horizontal.hpp tuple implementation in the sandbox slim/test directory. The unrolled bar in the pag12 bar chart corresponds to the: tuple_impl.bcon12_vertical.hpp In contrast to the gcc4_8 compiler, with the clangxx compiler, the relative qualitative performance, is just the opposite. IOW, the bcon12_horizontal implementation is faster than the bcon12_vertical implementation. In fact, the rate of change of the performance difference accelerates as tree depth goes from 2 to 4. The rate of change is so stark that it suggests, at least to me, there may be some bug in clang. Of course that conclusion is based on almost no knowledge, on my part, of the clang implementation. The tuple_benchmark_filt.py can be modified to filter out other parts of the benchmark run output, which is here: http://svn.boost.org/svn/boost/sandbox/variadic_templates/sandbox/slim/test… In conclusion, whether it's best to use vertical or horizontal tuple implementation depends on the compiler. -regards, Larry

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Build errors with msvc/release/pdb
by Christoph Macheiner 19 Nov '12

19 Nov '12

The following libraries generate errors when using msvc, building for release and generating the program debug database: date_time, locale, math (all), thread, wave. Except for math, this seems to be caused by having at least one directory specified in the /Fd option. Also, there are 251 .pdb files in the boost root directory instead of their respective output directory (presumably from serialization, unit_test, math, and most probably others). The command-line is: bjam link=shared runtime-link=shared variant=release --layout=system --stagedir=.\stage stage debug-symbols=on debug-store=database I am at a loss on how to fix this. Can someone help? On a related note, the .pdb files are automatically generated when building for debug. Is there an easy switch somewhere in the sources, so that I can turn this on globally also for release as a work-around? For reference, below is the output for the first file for each library, plus contents of the corresponding .rsp file Thanks, Christoph. ======================================== compile-c-c++ bin.v2\libs\date_time\build\msvc-11.0\release\debug-store-database\debug-symbols-on\threading-multi\gregorian\greg_month.obj greg_month.cpp libs\date_time\src\gregorian\greg_month.cpp : fatal error C1033: cannot open program database 'd:\dev\boost_1_52_0\gregorian\greg_month.pdb' call "C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\vcvarsall.bat" x86 >nul cl /Zm800 -nologo @"bin.v2\libs\date_time\build\msvc-11.0\release\debug-store-database\debug-symbols-on\threading-multi\gregorian\greg_month.obj.rsp" ---------------------------------------- "libs\date_time\src\gregorian\greg_month.cpp" -Fo"bin.v2\libs\date_time\build\msvc-11.0\release\debug-store-database\debug-symbols-on\threading-multi\gregorian\greg_month.obj" /Fd"gregorian\greg_month.pdb" -TP /O2 /Zi /Ob2 /W3 /GR /MD /Zc:forScope /Zc:wchar_t /wd4675 /EHs -c -DBOOST_ALL_DYN_LINK=1 -DBOOST_ALL_NO_LIB=1 -DDATE_TIME_INLINE -DNDEBUG "-I." ======================================== compile-c-c++ bin.v2\libs\locale\build\msvc-11.0\release\debug-store-database\debug-symbols-on\threading-multi\encoding\codepage.obj codepage.cpp libs\locale\src\encoding\codepage.cpp : fatal error C1033: cannot open program database 'd:\dev\boost_1_52_0\encoding\codepage.pdb' call "C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\vcvarsall.bat" x86 >nul cl /Zm800 -nologo @"bin.v2\libs\locale\build\msvc-11.0\release\debug-store-database\debug-symbols-on\threading-multi\encoding\codepage.obj.rsp" ---------------------------------------- "libs\locale\src\encoding\codepage.cpp" -Fo"bin.v2\libs\locale\build\msvc-11.0\release\debug-store-database\debug-symbols-on\threading-multi\encoding\codepage.obj" /Fd"encoding\codepage.pdb" -TP /O2 /Zi /Ob2 /W3 /GR /MD /Zc:forScope /Zc:wchar_t /wd4675 /EHs -c -DBOOST_ALL_NO_LIB=1 -DBOOST_LOCALE_DYN_LINK=1 -DBOOST_LOCALE_NO_POSIX_BACKEND=1 -DBOOST_SYSTEM_DYN_LINK=1 -DBOOST_THREAD_NO_LIB=1 -DNDEBUG "-I." ======================================== compile-c-c++ bin.v2\libs\math\build\msvc-11.0\release\debug-store-database\debug-symbols-on\threading-multi\assoc_laguerre.obj assoc_laguerre.cpp libs\math\build\..\src\tr1\assoc_laguerre.cpp(6) : error C2858: command-line option 'program database name (/Fdd:\dev\boost_1_52_0\assoc_laguerre.pdb)' inconsistent with precompiled header, which used '/Fdd:\dev\boost_1_52_0\vc110.pdb' libs\math\build\..\src\tr1\assoc_laguerre.cpp(6) : error C2859: d:\dev\boost_1_52_0\assoc_laguerre.pdb is not the pdb file that was used when this precompiled header was created, recreate the precompiled header. call "C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\vcvarsall.bat" x86 >nul cl /Zm800 -nologo @"bin.v2\libs\math\build\msvc-11.0\release\debug-store-database\debug-symbols-on\threading-multi\assoc_laguerre.obj.rsp" ---------------------------------------- "libs\math\build\..\src\tr1\assoc_laguerre.cpp" -Fo"bin.v2\libs\math\build\msvc-11.0\release\debug-store-database\debug-symbols-on\threading-multi\assoc_laguerre.obj" /Fd"assoc_laguerre.pdb" -Yu"pch.hpp" -Fp"bin.v2\libs\math\build\msvc-11.0\release\debug-store-database\debug-symbols-on\threading-multi\pch.pch" -TP /O2 /Zi /Ob2 /W3 /GR /MD /Zc:forScope /Zc:wchar_t /wd4675 /EHs -c -DBOOST_ALL_NO_LIB=1 -DBOOST_BUILD_PCH_ENABLED -DBOOST_MATH_TR1_DYN_LINK=1 -DNDEBUG "-I." "-Ilibs\math\src\tr1" ======================================== compile-c-c++ bin.v2\libs\thread\build\msvc-11.0\release\debug-store-database\debug-symbols-on\threading-multi\win32\thread.obj thread.cpp libs\thread\src\win32\thread.cpp : fatal error C1033: cannot open program database 'd:\dev\boost_1_52_0\win32\thread.pdb' call "C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\vcvarsall.bat" x86 >nul cl /Zm800 -nologo @"bin.v2\libs\thread\build\msvc-11.0\release\debug-store-database\debug-symbols-on\threading-multi\win32\thread.obj.rsp" ---------------------------------------- "libs\thread\src\win32\thread.cpp" -Fo"bin.v2\libs\thread\build\msvc-11.0\release\debug-store-database\debug-symbols-on\threading-multi\win32\thread.obj" /Fd"win32\thread.pdb" -TP /O2 /Zi /Ob2 /W4 /GR /MD /Zc:forScope /Zc:wchar_t /wd4675 /EHs -c -DBOOST_ALL_NO_LIB=1 -DBOOST_SYSTEM_DYN_LINK=1 -DBOOST_SYSTEM_NO_DEPRECATED -DBOOST_THREAD_BUILD_DLL=1 -DBOOST_THREAD_DONT_USE_CHRONO -DBOOST_THREAD_THROW_IF_PRECONDITION_NOT_SATISFIED -DNDEBUG "-I." ======================================== compile-c-c++ bin.v2\libs\wave\build\msvc-11.0\release\debug-store-database\debug-symbols-on\threading-multi\cpplexer\re2clex\aq.obj aq.cpp libs\wave\src\cpplexer\re2clex\aq.cpp : fatal error C1033: cannot open program database 'd:\dev\boost_1_52_0\cpplexer\re2clex\aq.pdb' call "C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\vcvarsall.bat" x86 >nul cl /Zm800 -nologo @"bin.v2\libs\wave\build\msvc-11.0\release\debug-store-database\debug-symbols-on\threading-multi\cpplexer\re2clex\aq.obj.rsp" ---------------------------------------- "libs\wave\src\cpplexer\re2clex\aq.cpp" -Fo"bin.v2\libs\wave\build\msvc-11.0\release\debug-store-database\debug-symbols-on\threading-multi\cpplexer\re2clex\aq.obj" /Fd"cpplexer\re2clex\aq.pdb" -TP /O2 /Zi /Ob2 /W3 /GR /MD /Zc:forScope /Zc:wchar_t /wd4675 /EHs -c -DBOOST_ALL_DYN_LINK=1 -DBOOST_ALL_NO_LIB=1 -DNDEBUG -D_CRT_SECURE_NO_DEPRECATE -D_SCL_SECURE_NO_DEPRECATE "-I." ========================================

2 1

User config commands needed to find Clang tools ar and ranlib
by Paul A. Bristow 19 Nov '12

19 Nov '12

I am trying to use the Clang compiler to build a Boost.Test library and have now found the necessary user-config.jam to select the compiler (thanks Jurgen Hunold) , but the link stage tools are not being found. Can anyone suggest what bjam incantation is needed ? Thanks Paul clang-linux.archive i:\boost-trunk\boost\bin.v2\libs\test\build\clang-linux-3.1\debug\link-static\runtime-link-static\th reading-multi\libboost_prg_exec_monitor-clang31-mt-sd-1_53.lib '"ar"' is not recognized as an internal or external command, operable program or batch file. '"ranlib"' is not recognized as an internal or external command, operable program or batch file. "ar" rc "i:\boost-trunk\boost\bin.v2\libs\test\build\clang-linux-3.1\debug\link-static\runtime-link-static\t hreading-multi\libboost_prg_exec_monitor-clang31-mt-sd-1_53.lib" "i:\boost-trunk\boost\bin.v2\libs\test\build\clang-linux-3.1\debug\link-static\runtime-link-static\t hreading-multi\execution_monitor.obj" "i:\boost-trunk\boost\bin.v2\libs\test\build\clang-linux-3.1\debug\link-static\runtime-link-static\t hreading-multi\debug.obj" "i:\boost-trunk\boost\bin.v2\libs\test\build\clang-linux-3.1\debug\link-static\runtime-link-static\t hreading-multi\cpp_main.obj" "ranlib" "i:\boost-trunk\boost\bin.v2\libs\test\build\clang-linux-3.1\debug\link-static\runtime-link-static\t hreading-multi\libboost_prg_exec_monitor-clang31-mt-sd-1_53.lib" ...failed clang-linux.archive i:\boost-trunk\boost\bin.v2\libs\test\build\clang-linux-3.1\debug\link-static\runtime-link-static\th reading-multi\libboost_prg_exec_monitor-clang31-mt-sd-1_53.lib... My user-config.jam contains using clang : #version 3.1 : # compiler "C:/mingw32-dw2/bin/clang++.exe" #"C:/mingw32-dw2/bin/ar.exe" <<<< actual locations of tools #"C:/mingw32-dw2/bin/ranlib.exe" <<<< actual locations of tools : # options <cxxflags>-v # verbose for testing. <cxxflags>-IC:/mingw32-dw2/include/c++/4.6.3 # for stdlib? #e:/dev/apps/mingw64/include/c++/4.7.2 <cxxflags>-IC:/mingw32-dw2/i686-w64-mingw32/include #e:/dev/apps/mingw64/include/c++/4.7.2/x86_64-w64-mingw32 # <cxxflags>-std="c++11" <root>"C:/mingw32-dw2/bin" # attempt to find the link tools ; --- Paul A. Bristow, Prizet Farmhouse, Kendal LA8 8AB UK +44 1539 561830 07714330204 pbristow(a)hetp.u-net.com

1 0

[container] Missing image
by Klaim - Joël Lamotte 19 Nov '12

19 Nov '12

Hi, I thought I pointed it already last year but there is at least one missing important image in the boost container documentation: http://www.boost.org/doc/libs/1_52_0/doc/html/container/non_standard_contai… Joel Lamotte

1 0

[#pragma once]
by Sid Sacek 18 Nov '12

18 Nov '12

I've worked with the MSVC, Sun and GCC compilers. Each one of them supports #pragma once. Is there any reason to wrap this pragma within #ifdefs? Are there any compilers out there today that don't support this #pragma? #if defined( _MSC_VER ) && ( _MSC_VER >= 1020 ) # pragma once #endif Could we change this coding pattern so that it no longer looks like MSVC is being selfish? -Sid Sacek

17 20

Re: [boost] Countertree
by Leo Goodstadt 18 Nov '12

18 Nov '12

> Subject: Re: [boost] Review Wizard Report for November 2012 > Hi all, > I would like to request a formal review of the library ?Countertree + > Suballocator? [countertree] > > Project location ( zip file with code and documentation) : > https://dl.dropbox.com/u/8437476/works/countertree_code_doc.zip > > Quick view of documentation with code download : > https://dl.dropbox.com/u/8437476/works/countertree/index.html > > For the people who don't know this project, this is a description : > > *COUNTERTREE* > > 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 Among other things, countertree would allow the boost Statistical Accumulators Library to support rolling median and rolling quantiles efficiently. This would be very useful. I had previously had to hack the tree class in the Policy-Based Data Structures part of the gnu c++ library. (see http://gcc.gnu.org/onlinedocs/libstdc++/ext/pb_ds/tree_order_statistics_nod…) Leo Goodstadt

4 5

Review Wizard Report for November 2012
by Ronald Garcia 17 Nov '12

17 Nov '12

============================================== Review Wizard Status Report for November 2012 ============================================== News ==== 1. ODEInt Reviewed 2. Boost 1.52.0 Released. No New Libraries. 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: * Predef - reviewed February 2012; review manager: Joel Falcou. * Coroutine - reviewed September 2012; review manager: Hartmut Kaiser. The following libraries have been accepted to Boost, but have not yet been submitted to SVN: * Constrained Value - accepted September 2010; author: Robert Kawulak. * GIL.IO - accepted January 2011; author: Christian Henning. * Contract - accepted September 2012; author: Lorenzo Caminiti. The following libraries have been accepted and submitted to SVN, but have not yet appeared in a release: * Atomic - accepted July 2011; author Helge Bahmann. * Type Traits Introspection - accepted August 2011; author: Edward Diener. * Lockfree - accepted August 2011; author: Tim Blechmann. The following libraries have been accepted provisionally to Boost, but have not been submitted for mini-review and full acceptance: * Endian - accepted provisionally November 2011; author: Beman Dawes. * Log - accepted provisionally March 2010; author: Andrey Semashev. 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 cmu dot edu" and "phillips at pacific dot mps dot ohio-state dot edu" 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) * Pimpl (M) * Sorting (M) * Quaternions, Vectors, Matrices (M) * Variadic Macro Data (M) * Block Pointer (M) * Singularity (M) * Extended Complex Numbers (M) * Metaparse (M) * Polygon: Voronoi Extensions * Coroutine * Range Extensions * Nowide (M) * Array (M) * TypeIndex (M) * STL Extensions (M) ``(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. Pimpl ----- :Author: Vladimir Batov :Review Manager: Needed :Download: https://github.com/boost-vault/Miscellaneous/blob/master/Pimpl.zip :Description: The Pimpl idiom is a simple yet robust technique to minimize coupling via the separation of interface and implementation and then implementation hiding. This library provides a convenient yet flexible and generic deployment technique for the Pimpl idiom. It's seemingly complete and broadly applicable, yet minimal, simple and pleasant to use. Sorting ------- :Author: Steven Ross :Review Manager: Needed :Download: https://github.com/boost-vault/Sorting :Description: A grouping of 3 templated hybrid radix/comparison-based sorting algorithms that provide superior worst-case and average-case performance to std::sort: integer_sort, which sorts fixed-size data types that support a rightshift (default of >>) and a comparison (default of <) operator. float_sort, which sorts standard floating-point numbers by safely casting them to integers. string_sort, which sorts variable-length data types, and is optimized for 8-bit character strings. All 3 algorithms have O(n(k/s + s)) runtime where k is the number of bits in the data type and s is a constant, and limited memory overhead (in the kB for realistic inputs). In testing, integer_sort varies from 35% faster to 2X as fast as std::sort, depending on processor, compiler optimizations, and data distribution. float_sort is roughly 70% faster than std::sort. string_sort is roughly 2X as fast as std::sort. Quaternions, Vectors, Matrices ------------------------------ :Author: Emil Dotchevski :Review Manager: Needed :Download: http://www.revergestudios.com/boost-qvm/ :Description: QVM defines a set of generic functions and operator overloads for working with quaternions, vectors and matrices of static size. The library also defines vector and matrix data types, however it allows users to introduce their own types by specializing the q_traits, v_traits and m_traits templates. Variadic Macro Data ------------------- :Author: Edward Diener :Review Manager: Needed :Download: `Boost Sandbox <http://svn.boost.org/svn/boost/sandbox/variadic_macro_data/>`__ :Description: This library adds support and functionality for variadic macros to Boost as well as integrating variadic macros with the Boost PP library without changing the latter library in any way. 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) Metaparse --------- :Author: Abel Sinkovics :Review Manager: Needed :Download: http://abel.web.elte.hu/metaparse/metaparse.zip :Description: Metaparse is a library for constructing parsers parsing at compile-time based on template metaprogramming. The parsers built with the library take boost::mpl::strings as input and can produce - types - objects (types with public static members) - callable C++ functions (types with public static method) - template metafunction classes as output (based on the input being parsed). On compilers supporting constexpr the library provides the following syntactic sugar for writing the input of the parsers: BOOST_STRING("this is a string") The library can be used for implementing DSLs in C++, including DSLs making C++ template metaprogramming easier (see examples). Polygon: Voronoi Extensions --------------------------- :Author: Andril Sydorchuk :Review Manager: Lucanus Simonson :Download: http://svn.boost.org/svn/boost/sandbox/gtl/ :Description: This library extends Boost.Polygon with the following features: - Robust and efficient implementation of the sweepline algorithm that allows to construct Voronoi diagram, Delaunay triangulation and medial axis of a set of points and line segments. - Coordinates of the output geometries are computed within the 64 machine epsilon relative error (6 mantissa bits). - Voronoi diagram data structure that allows efficient traversal and data association with the output Voronoi graph. - No 3rd party dependencies (e.g. GMP, MPFR), all the required multiple precision types are implemented as part of the library. - The input and output coordinate type domains are configurable via coordinate type traits, thus allowing to compute coordinates of the Voronoi vertices within any required precision. - The full construction of the Voronoi diagram of 100 000 points takes only 0.27 seconds (see benchmarks). Coroutine --------- :Author: Oliver Kowalke :Review Manager: Hartmut Kaiser :Download: http://gitorious.org/boost-dev/boost-dev/archive-tarball/coroutine :Description: This library is an implementation of coroutines and generators using Boost.Context. 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. TypeIndex --------- :Author: Antony Polukhin :Review Manager: Needed :Download: https://github.com/apolukhin/type_index :Description: TypeIndex is an extended C++11 type_index library, that * works with disabled RTTI * can store const-volatile-reference info about types (if user requested it) * has all the functionality of std::type_index * has portable across compilers and platforms functionality for getting demangled type names * works across modules/shared libraries * does not require C++11 to work 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. Libraries under development =========================== See http://svn.boost.org/trac/boost/wiki/LibrariesUnderConstruction for a current listing of libraries under development.

3 8

[1.53] request to merge lockfree (c++11 only)
by Tim Blechmann 17 Nov '12

17 Nov '12

hi all, i'm not sure about the state of atomic, as the original author hardly reacts on emails and atm, i don't have the time to adopt it ... i'd therefore request permission to merge boost.lockfree into release, depending on std::atomic<>. this means, that it will require gcc-4.8 or msvc 2012 in c++11 mode to compile it (not sure about clang++, as their c++11 support under linux is pretty broken). the architecture of boost.lockfree is modular, so once boost.atomic is merged, it is trivial to use it again and allow use of the library with pre-c++11 compilers ... this is far from ideal, but boost.atomic has been blocking the release of boost.lockfree for a long time and it doesn't look like that it will be available before std::atomic<> is widely supported ... thoughts? tim

5 13

1.53 schedule change
by Daniel James 17 Nov '12

17 Nov '12

Hello everyone, I just noticed that I forgot to account for Christmas when setting the schedule for 1.53. I've adjusted it so that the deadlines for new libraries and major changes are a week earlier (as specified on the release schedule page). Sorry about that. There's still 3 weeks before the new library deadline, but please let us know soon if you have a new library for 1.53. thanks, Daniel

3 6

Boost.Process 0.5: Another update/potential candidate for an official library
by Boris Schaeling 17 Nov '12

17 Nov '12

I've uploaded a new version of Boost.Process 0.5 to <http://www.highscore.de/boost/process0.5/>: - Made child movable and non-copyable on Windows (destructor closes handles) - Added cross-platform helpers in a new header file boost/process/mitigate.hpp - Updated and improved documentation (eg. FAQ is new) - Added the POSIX initializer notify_io_service (Boost.Asio helper) - Minor bug fixes and improvements (eg. in search_path() on Windows) At this point there is nothing left on my todo list. I got quite a lot of feedback so far and would appreciate if people can look at this new version again. If there are no major shortcomings found, I'll ask for a formal review. Boris

10 53

[container] container_detail::pair piecewise constructor
by László Szécsi 17 Nov '12

17 Nov '12

Hi everyone, boost::container::container_detail::pair's piecewise constructor is missing, as acknowledged in a comment. This makes container::flat_map::emplace less useful (perhaps useless) as the following will not work: boost::container::flat_multimap<TestKey, TestValue> testMap; testMap.emplace(boost::container::container_detail::piecewise_construct, boost::make_tuple(30), boost::make_tuple(50)); where both TestKey and TestValue are non-copyable, moveable classes with a constructor taking an int. The compilation error message will correctly say that boost::container::container_detail::pair does not have a constructor with three arguments. I tried to implement the missing piecewise constructor based on std::pair's in the g++ standard libraries. I failed at it, so I would like to request some assistance and education. This is where I got: // from the standard lib template<std::size_t _Num> struct _Build_index_tuple { typedef typename _Build_index_tuple<_Num-1>::__type::__next __type; }; // from the standard lib template<> struct _Build_index_tuple<0> { typedef _Index_tuple<> __type; }; template <class... Args1, class... Args2> pair(piecewise_construct_t, ::boost::tuple<Args1...> first_args, ::boost::tuple<Args2...> second_args) : pair(::boost::move(first_args), ::boost::move(second_args), typename _Build_index_tuple<sizeof...(Args1)>::__type(), typename _Build_index_tuple<sizeof...(Args2)>::__type()) {} template<typename... Args1, std::size_t... Indices1, typename... Args2, std::size_t... Indices2> explicit pair(tuple<Args1...> tuple1, tuple<Args2...> tuple2, _Index_tuple<Indices1...>, _Index_tuple<Indices2...>) : first(::boost::forward<Args1>(std::get<Indices1>(tuple1))...), second(::boost::forward<Args2>(std::get<Indices2>(tuple2))...) { } This gets me a recursive error message far too long to quote, starting with: error C2664: 'boost::container::container_detail::pair<Key,T>::pair(std::pair<Key,T> &&)' : cannot convert parameter 3 from 'boost::tuples::tuple<int,boost::tuples::null_type // lot of null_types omitted to 'boost::tuples::tuple<boost::tuples::null_type, // lot of null_types omitted I used the VS2012 Nov CTP compiler. I understand that variadic templates have not been very portable and boost::unordered, which has a piecewise constructor implementation, does it completely differently and much more painfully. But is there a reason for the approach I tried not to work with boost at all? Could you please help me fix this code? Thank you very much, Laszlo Szecsi

3 3

Updated serialization performance tests
by Brian Wood 16 Nov '12

16 Nov '12

Shalom I've updated this page -- http://webEbenezer.net/comparison.html with results from Boost 1.52. A few notes about the testing: I decided to use -O2 on the Linux/g++ tests. In previous tests I used -O3. I hadn't updated the Windows test results since the Boost 1.48 time-frame. Around Boost 1.51 I had to start building the serialization library in Boost with runtime-link=static in order to get the Windows tests to build. I haven't understood why that became necessary, but the results for the serialization library in Boost seem to have been adversely affected by this. On Windows, I now report that tests built with the serialization library in Boost are over 1.8 times slower than parallel Ebenezer tests. Previously I reported the tests built with the serialization library in Boost were between 1.7 and 1.8 times slower than the Ebenezer tests. -- Brian Ebenezer Enterprises -- making programming fun again. http://webEbenezer.net

1 0

Boost.Test and Xcode 4.5 in C++11 Mode
by Dean Michael Berris 16 Nov '12

16 Nov '12

Hi Everyone, I'm trying to build Boost.Test in trunk in C++11 mode with Apple's released Clang compiler with Xcode 4.5. Is this supported by Boost.Test? I keep getting this error somewhere deep in some preprocessor parts which is far outside my understanding. Here's my user-config.jam: using clang : : : <cxxflags>-Wall <cxxflags>-Wself-assign <cxxflags>-std=c++11 <cxxflags>-stdlib=libc++ <linkflags>-stdlib=libc++ ; I ask because I'm using Boost.Test as my current unit testing framework for cpp-netlib. I'm going to need to make a decision on whether I can continue using Boost.Test in C++11 mode as cpp-netlib is moving to C++11-only in its next version. Thanks in advance. -- Dean Michael Berris www.deanberris.com

5 13

[test] A new ERROR in trunk including C++11 features on C++98 mode
by Vicente J. Botet Escriba 16 Nov '12

16 Nov '12

Hi, there is yet an error including C++11 features. Please could you take care of it? Thanks, Vicente darwin.compile.c++ ../../../bin.v2/libs/test/build/darwin-4.2.1/debug/link-static/threading-multi/framework.o In file included from ../../../boost/test/tools/assertion.hpp:19, from ../../../boost/test/tools/impl.hpp:25, from ../../../boost/test/test_tools.hpp:373, from ../../../boost/test/impl/framework.ipp:27, from ../../../libs/test/src/framework.cpp:16: ../../../boost/test/utils/is_forward_iterable.hpp:58: error: ‘>>’ should be ‘> >’ within a nested template argument list ../../../boost/test/utils/is_forward_iterable.hpp:61: error: ‘>>’ should be ‘> >’ within a nested template argument list "g++" -ftemplate-depth-128 -O0 -fno-inline -Wall -pedantic -g -gdwarf-2 -fexceptions -DBOOST_ALL_NO_LIB=1 -I"../../.." -c -o "../../../bin.v2/libs/test/build/darwin-4.2.1/debug/link-static/threading-multi/framework.o" "../../../libs/test/src/framework.cpp" ...failed darwin.compile.c++ ../../../bin.v2/libs/test/build/darwin-4.2.1/debug/link-static/threading-multi/framework.o...

6 16

BOOST_FUSION_ADAPT_STRUCT - Printing Array Elements
by forums_mp 16 Nov '12

16 Nov '12

Given the snippet below. How do I print the contents within the array ? I'd expect to see a counting pattern when the array is encountered but that's not the case. Thanks in advance. [code] #include <boost/mpl/eval_if.hpp> #include <boost/mpl/identity.hpp> #include <boost/mpl/next_prior.hpp> #include <boost/fusion/mpl.hpp> #include <boost/fusion/adapted.hpp> // BOOST_FUSION_ADAPT_STRUCT // boost::fusion::result_of::value_at #include <boost/fusion/sequence/intrinsic/value_at.hpp> #include <boost/fusion/include/value_at.hpp> // boost::fusion::result_of::size #include <boost/fusion/sequence/intrinsic/size.hpp> #include <boost/fusion/include/size.hpp> // boost::fusion::at #include <boost/fusion/sequence/intrinsic/at.hpp> #include <boost/fusion/include/at.hpp> # include <iostream> # include <vector> typedef std::vector < int > INT_VEC ; // Your existing struct struct my_struct { int i; bool j; int arr1 [ 100 ]; // INT_VEC vv ; // my_struct() // : vv ( 100 ) // {} }; // Generate an adapter allowing to view "Foo" as a Boost.Fusion sequence BOOST_FUSION_ADAPT_STRUCT( my_struct, (int, i) (bool, j) (int, arr1[ 100 ] ) // (int, vv[100]) ) template <typename T2> struct parse_foo { static void parse(T2 & f); }; struct display { template <typename T> void operator()(T& t) const { std::printf(" --%s--%s-- \n", typeid(t).name(), boost::lexical_cast<std::string>(t).c_str()); if (typeid(t).name()[0] == 'c') std::printf(" --%s--%s-- \n", typeid(t).name(), t); parse_foo<T>::parse(t); } }; template <> void parse_foo<int >::parse(int & f) { std::cout << f << std::endl; } template <> void parse_foo<char>::parse(char & f) {}; template <> void parse_foo<bool>::parse(bool & f) { std::cout << f << std::endl; }; #include <boost/fusion/include/sequence.hpp> #include <boost/fusion/include/algorithm.hpp> #include <boost/fusion/include/vector.hpp> #include <boost/fusion/include/adapt_struct.hpp> #include <boost/lexical_cast.hpp> int main() { my_struct f; f.i = 33 ; f.j = false ;; for ( int odx ( 0 ); odx < 100; ++odx ) { f.arr1 [ odx ] = odx ; } boost::fusion::for_each(f, display()); } [/code] -- View this message in context: http://boost.2283326.n4.nabble.com/BOOST-FUSION-ADAPT-STRUCT-Printing-Array… Sent from the Boost - Dev mailing list archive at Nabble.com.

1 0

Re: [boost] [Boost-commit] svn:boost r81360 - in trunk: boost/algorithm libs/algorithm/test
by Steven Watanabe 15 Nov '12

15 Nov '12

AMDG On 11/15/2012 11:45 AM, marshall(a)idio.com wrote: > <snip> > + // construct/copy > + BOOST_CONSTEXPR basic_string_ref () > +#ifdef BOOST_NO_CXX11_NULLPTR > + : ptr_(NULL), len_(0) {} > +#else > + : ptr_(nullptr), len_(0) {} > +#endif Really? The two branches have exactly the same effect. The only reason to prefer nullptr is aesthetic and this is more than offset by the #ifdef. > + > + basic_string_ref(const charT* str) > + : ptr_(str), len_(std::strlen(str)) {} > + strlen only works for char. You need to use traits::length > +#ifndef BOOST_NO_CXX11_HDR_INITIALIZER_LIST > +// !! How do I do this? Look how initializer_lists work! > + basic_string_ref(std::initializer_list<charT> il); // TODO > +#endif > + Although this can be implemented, it's incredibly dangerous, because the string_ref will be left dangling when the initializer_list goes out of scope. > + > + // iterators > + BOOST_CONSTEXPR const_iterator begin() const { return ptr_; } > + BOOST_CONSTEXPR const_iterator cbegin() const { return ptr_; } > + BOOST_CONSTEXPR const_iterator end() const { return ptr_ + len_; } > + BOOST_CONSTEXPR const_iterator cend() const { return ptr_ + len_; } > + const_reverse_iterator rbegin() const { return const_reverse_iterator (end()); } > + const_reverse_iterator crbegin() const { return const_reverse_iterator (end()); } > + const_reverse_iterator rend() const { return const_reverse_iterator (begin()); } > + const_reverse_iterator crend() const { return const_reverse_iterator (begin()); } > + Check for tabs? > + // capacity > + BOOST_CONSTEXPR size_type max_size() const { return len_; } I'm not convinced that this definition is correct. Returns: the size of the largest possible string. Note that this does not say that it returns the maximum size that this particular string_ref object can hold without reassignment. > + > + int compare(basic_string_ref x) const { > + int cmp = std::memcmp ( ptr_, x.ptr_, std::min(len_, x.len_)); > + return cmp != 0 ? cmp : ( len_ == x.len_ ? 0 : len_ < x.len_ ? -1 : 1 ); > + } > + > + bool starts_with(charT c) const { return !empty() && front() == c; } > + bool starts_with(basic_string_ref x) const { > + return len_ >= x.len_ && std::memcmp ( ptr_, x.ptr_, x.len_ ) == 0; > + } > + > + bool ends_with(charT c) const { return !empty() && back() == c; } > + bool ends_with(basic_string_ref x) const { > + return len_ >= x.len_ && std::memcmp ( ptr_ + len_ - x.len_, x.ptr_, x.len_ ) == 0; > + } > + You can only use memcmp for char. You have to use traits::compare here. > + > +// Have to use traits here > + size_type find(basic_string_ref s) const { > + const_iterator iter = std::find_if ( this->cbegin (), this->cend (), > + s.cbegin (), s.cend (), traits::eq ); > + return iter = this->cend () ? npos : std::distance ( this->cbegin (), iter ); > + } > + I think you mean std::search, not std::find_if. > + size_type find(charT c) const { > +#ifdef BOOST_NO_CXX11_LAMBDAS > + const_iterator iter = std::find_if ( this->cbegin (), this->cend (), > + detail::string_ref_traits_eq<charT, traits> ( c )); > +#else > + const_iterator iter = std::find_if ( this->cbegin (), this->cend (), > + [c] ( charT val ) { return traits::eq ( c, val ); } ); > +#endif > + return iter == this->cend () ? npos : std::distance ( this->cbegin (), iter ); > + } > + As with NULL/nulptr, I don't see the point of using C++11 lambdas if you have to #ifdef it with a C++03 implementation. In Christ, Steven Watanabe

2 1

[multiprecision] OK to merge to Trunk?
by John Maddock 15 Nov '12

15 Nov '12

Folks, Unless there are any objections, I'd like to merge the multiprecision library to SVN Trunk pretty soon. Here are the main changes since the review, which have mostly concentrated on the interface changes: * Non-expression template operators further optimized with rvalue reference support. * Many functions made `constexp`. * Differentiate between explicit and implicit conversions in the number constructor. * Removed "mp_" prefix from types. * Allowed mixed precision arithmetic. * Changed ExpressionTemplates parameter to class `number` to use enumerated values rather than true/false. * Changed ExpressionTemplate parameter default value to use a traits class so that the default value depends on the backend used. * Added support for fused-multiply-add/subtract with GMP support. * Tweaked expression template unpacking to use fewer temporaries when the LHS also appears in the RHS. * Refactored `cpp_int_backend` based on review comments with new template parameter structure. * Added additional template parameter to `mpfr_float_backend` to allow stack-based allocation. * Added section on mixed precision arithmetic, and added support for operations yielding a higher precision result than either of the arguments. * Added overloads of integer-specific functions for built in integer types. Things requested in review, but not yet done: * We can reuse temporaries in multiple subtrees (temporary caching). Low priority for now. * cpp_dec_float should round to nearest. Chris currently has no time for this, and it's really hard to do *right*. * A 2's complement fixed precision int that uses exactly N bits and no more. Refactoring of cpp_int should make this easier to add as an option in future. There are also documentation updates pending (mostly relating to the new improved performance results), and more tests I want to add/run, bit basically I need to get things widely tested to move forward now. Release schedule wise, I think it'll be hard to get things ready for the next release, but the release after that really should be on the cards. So basically now is the last chance for folks to complain before the interface gets ossified ;-) As ever current code is in the sandbox under /big_number/ and docs can be viewed online here: http://svn.boost.org/svn/boost/sandbox/big_number/libs/multiprecision/doc/h… Regards, John.

7 10

boost filesystem path as utf-8 revisited
by Rush Manbert 15 Nov '12

15 Nov '12

In the original thread, I found this reply by Beman: ----------------- > > > How exactly do I imbue UTF-8 codecvt in a path? I Googled around and > couldn't find anything. There are two approaches: * If you always want all class path arguments and returned values with a value type of char to be treated as being UTF-8 encoded, and aren't worried about changing a potentially dangerous global, then do this: #include <boost/filesystem/detail/utf8_codecvt_facet.hpp> ... std::locale global_loc = std::locale(); std::locale loc(global_loc, new boost::filesystem::detail::utf8_codecvt_facet); boost::filesystem::path::imbue(loc); ----------------- I do want what is described and would like to use this approach, but we use boost::filesystem all over the place and in our code we never do any sort of "global initialization", so I'm trying to figure out how to get the code snippet executed. I can see two ways to approach this: 1) Add this code snippet to the boost::filesystem::path constructor. But is it too late then? 2) Define a class whose only purpose is to execute this code when it is constructed and arrange to have a static singleton instance of the class defined. In one of our libraries we need to be very careful about static class construction order, so this may be difficult. I haven't dealt with this sort of issue in quite a while and I may be a little rusty. Any suggestions? Are there new goodies in C++ that might help me? Thanks, Rush

3 3

program_options::store() interface extension
by ST 15 Nov '12

15 Nov '12

Hi, I need to supply to my app a config file with following entries: item1 = 123 item2 = 435 item3 = 345 ... itemN = 562 where N is not known in advance, so there is no way to register such options. The only way to deal with them is to pass them as unregistered options and then use collect_unrecognized(). But then dealing with a vector<string> is not quit convenient. My suggestion is to add an a storeUnregistered flag to the store() function which will be false by default, but if set to true, will store all unregistered options with their values as strings. It will be possible then to check whether an item was provided like this: vm.count("item1") and cast its value like this: vm["item1"].as<int>() . Or is there already a good way to do what I need? Thank you in advance, ST

2 1

Re: [boost] [container] container_detail::pair piecewise constructor
by László Szécsi 15 Nov '12

15 Nov '12

I did some more research and it turns out std-style piecewise construction fails with VS2012 Nov CTP compiler, just like my attempt at adding piecewise construction to boost::container_detail::pair. In particular, the following dummy code compiles under g++ 4.7.1 but not under VS2012 Nov CTP. class Foo { public: template <class... Args1, class... Args2> Foo( const ::std::piecewise_construct_t, ::std::tuple<Args1...> first_args, ::std::tuple<Args2...> second_args) { } }; int main(){ Foo s( std::piecewise_construct, std::move( std::make_tuple(30) ), std::move( std::make_tuple(50) )); } I guess the time is not ripe for the container implementation to use true variadic templates yet. Is there ongoing effort to implement container_detail::pair's piecewise constructor in the same way as it was implemented in boost::unordered? Best regards, Laszlo Szecsi

1 0

[optional] Support for moving values
by Adam Badura 14 Nov '12

14 Nov '12

Are there any plans to add support for move constructors and assignment operators? I noticed that many Boost libraries miss that support. And it is especially "visible" in case of such utilities like boost::optional or boost::variant. Adam Badura

2 1

Boost 1.52.0 released!
by Marshall Clow 14 Nov '12

14 Nov '12

Release 1.52.0 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 numerous enhancements and bug fixes for existing libraries. For details, including download links, see http://www.boost.org/users/news/version_1_52_0 You can also download directly from SourceForge: http://sourceforge.net/projects/boost/files/boost/1.52.0/ 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 Beman Dawes Daniel James Eric Niebler Marshall Clow Rene Rivera Vladimir Prus

9 11

[optional] Types without assignment operator
by Adam Badura 14 Nov '12

14 Nov '12

I use boost::optional for deferred construction. Something similar to the idea described in "Bypassing expensive unnecessary default construction" in Boost.Optional documentation. Only in my case I do this because the mentioned construction requires virtual function calls and this cannot be done in owning object constructor and has to be postponed. So instead of accessing the object directly I always access it by a function. That function first checks if the object is already constructed (boost::optional is initialized) and if so just returns it. Otherwise it first constructs it. That approach requires only copy construction (or even move construction if boost::optional would support moving in the first place). Yet due to implementation details the embedded type has to be assignable as well. Even thou assignment operator will never be called (in this scenario). Is there a way to avoid this issue? If not then how about adding a function like "assign" (possibly named otherwise or with additional defaulting argument) which could assign by first destroying old object (if any) and then copy/move constructing a new one. This would obviously be bad from exception safety (guarantees) point of view, but well... don't call the function if you don't like that. And in scenarios like mine it would not be an issue since there would be no object to destroy anyway. (Also the function could assert/throw on that condition...) Now the Synopsis part of the Boost.Optional documentation does mention (Typed)InPlaceFactory assign operators which do look promising for solving this issue. But firstly they are not documented in following Detailed Semantics part. There is even no link in the Synopsis. (Is this docs bug? In which part? Missing docs or extra functions?) And secondly (Typed)InPlaceFactory support is "intrusive". I cannot add it to a class without changing the class itself. And in my case I cannot change the class (boost::program_options::options_description - why cannot it be copy assigned, that I don't know...). Maybe adding some extra wrapper would help but I don't think it would be a solution. Rather a somewhat ugly workaround. Adam Badura

3 8

Possible submission: Expanded std::bind compatible with std::move
by スマートアシュリー 14 Nov '12

14 Nov '12

I noticed that std::bind inst compatible with std::move.. I created a workaround for it in c++11 here. I would like to see it added to boost if thats ok. Please review my code... and let me know if its a viable candidate to be added to boost and what code changes are need before that. http://code-slim-jim.blogspot.jp/2012/11/perfect-forwarding-bind-compatable…

2 1

[type_erasure] issue when taking any<> by const ref
by Thomas Petit 13 Nov '12

13 Nov '12

Hi, I'm playing with the boost type erasure library (from the sandbox) and hit some issues. Imagine that I have an any accepting some concept : > typedef any<concept1<>, concept2<>> some_any_t; and a std::vector to put a few any in it : > std::vector<some_any_t> v; Then If I iterate over the vector by taking each element by reference >for(some_any_t& : v) >{ >} everything is fine and consistent with why I expect. However if I iterate by taking element by const ref >for(const some_any_t& : v) >{ >} then some issue appears. Here is an example showing the problems (with one any using a concept defined by BOOST_TYPE_ERASURE_FREE and one any using a concept defined by BOOST_TYPE_ERASURE_MEMBER) ................................................... #include <boost/type_erasure/any.hpp> #include <boost/type_erasure/operators.hpp> #include <boost/type_erasure/free.hpp> #include <boost/type_erasure/member.hpp> namespace mpl = boost::mpl; namespace te = boost::type_erasure; template <typename T> void free(const T& t) { std::cout << typeid(t).name() << std::endl; std::cout << "default free\n"; } void free(const int& i) { std::cout << typeid(i).name() << std::endl; std::cout << "int\n"; } BOOST_TYPE_ERASURE_FREE((has_free), free, 1); template<class T = te::_self> struct free_concept : mpl::vector<has_free<void(const T&)> > {}; typedef te::any<mpl::vector<te::copy_constructible<>, free_concept<>>> any_free_t; struct Base { virtual void member() const { std::cout << "Base member\n"; } }; struct Derived : public Base { virtual void member() const { std::cout << "Derived member\n"; } }; BOOST_TYPE_ERASURE_MEMBER((has_member), member, 0) struct member_concept : mpl::vector<has_member<void()> > {}; typedef te::any<mpl::vector<te::copy_constructible<>, member_concept>> any_member_t; int main() { any_free_t af1(5); any_free_t af2(5.0); std::vector<any_free_t> v; v.push_back(af1); v.push_back(af2); for(any_free_t& af : v) { free(af); } Base b; Derived d; std::vector<any_member_t> v2; v2.push_back(b); v2.push_back(d); for(any_member_t& am : v2) { am .member(); } } ....................................................... In the previous code, if add a const here : for(const any_free_t& af : v) { free(af); } then instead of calling the int overload of the free function and the template overload with a double type, the templated free function is called both time but, unfortunately the type of T is always the same as the any. Another point, if I add a const here : for(const any_member_t& am : v2) { am .member(); } then I get a compile error. (with visual 2012 and gcc 4.7) I'm a bit puzzled by this behavior. Are any<> types never supposed to be taken by const ref ? How can we iterate over anys while preserving constness ? Thanks. Thomas.

2 2

boost threads and linking boost statically into a DLL
by Carlos Empujon 13 Nov '12

13 Nov '12

Recently I had some trouble to linking boost statically into a DLL. After searching around I found that there has been a discussion on http://boost.2283326.n4.nabble.com/Fwd-Thread-Solution-to-conflict-with-MFC… However it seems that the patch proposed there (see below) did not make it into the trunk. Has there been a special reason why this has not been included into the normal distribution? Cheers, Carlos /** * tss.cpp * * This file is intended to correctly build a dll using boost::thread * It is taken from * * http://boost.2283326.n4.nabble.com/Fwd-Thread-Solution-to-conflict-with-MFC… * * $Id$ */ #include <windows.h> #include <boost/thread/detail/tss_hooks.hpp> extern "C" BOOL WINAPI RawDllMain(HINSTANCE hInstance, DWORD dwReason, LPVOID); namespace { BOOL WINAPI dll_callback(HANDLE h, DWORD dwReason, LPVOID p) { #ifdef _DLL if(!RawDllMain(static_cast<HINSTANCE>(h),dwReason,p)) return false; #endif // _DLL switch (dwReason) { case DLL_THREAD_DETACH: boost::on_thread_exit(); break; case DLL_PROCESS_DETACH: boost::on_process_exit(); break; } return true; } } extern "C" { extern BOOL (WINAPI * const _pRawDllMain)(HANDLE, DWORD, LPVOID)=&dll_callback; } namespace boost { void tss_cleanup_implemented() {} }

1 0

Release branch now open for merging
by Marshall Clow 12 Nov '12

12 Nov '12

The release branch (https://svn.boost.org/svn/boost/branches/release) is open for merging all stable changes from trunk, including bug fixes and major upgrades to existing libraries. Breaking changes should be coordinated via the mailing list with the developers of the other libraries affected. New libraries may be added, but require permission of a release manager. In other words, merging *does not* require permission from a release manager, except for new libraries. Boost Calendar with the release schedule: http://www.boost.org/development/index.html Release schedule explanation: http://svn.boost.org/trac/boost/wiki/ReleaseSchedule Release practices for developers: http://svn.boost.org/trac/boost/wiki/ImprovingPractices -- The Release Managers, Beman Dawes Daniel James Eric Niebler Marshall Clow Rene Rivera Vladimir Prus

1 0

[iostream] Bug in indirect_streambuf::seek_impl
by Jorge Lodos Vigil 12 Nov '12

12 Nov '12

Hi Currently indirect_streambuf::seek_impl always modifies input and output pointers with code: setg(0, 0, 0); setp(0, 0); See detail/indirect_streambuf.hpp. However, this is incorrect for dual seekable streams buffers which only modifies one set of pointers on each seek (in or out). As a consequence, dual seekable devices cannot be correctly seek. Those 2 lines should be replaced by: if (is_convertible<category, dual_seekable>::value) { if (which == BOOST_IOS::in) { setg(0, 0, 0); } if (which == BOOST_IOS::out) { setp(0, 0); } } else { setg(0, 0, 0); setp(0, 0); } I have created ticket https://svn.boost.org/trac/boost/ticket/7681 Thanks, Jorge

1 0

enable_if quirk? bug?
by Gennadiy Rozental 12 Nov '12

12 Nov '12

Hi, While working on some portability for Boost.Test I found this weird behavior. Abstracting out Boost.Test specific staff it goes like this: template<typename T> inline typename boost::enable_if_c<!boost::is_float<T>::value, int>::type foo( T&& v ); template<typename T> inline typename boost::enable_if_c<!boost::is_float<T>::value, int>::type foo( T&& v ) { return 1; } ... foo(1); MSVC 10 producing this error: error C2668: 'foo' : ambiguous call to overloaded function test.cpp(31): could be 'int foo<int>(T &&)' with [ T=int ] test.cpp(27): or 'int foo<int>(T &&)' with [ T=int ] while trying to match the argument list '(int)' Now change boost::enable_if_c with seemingly equivalent std::enable_if: template<typename T> inline typename std::enable_if<!boost::is_float<T>::value, int>::type foo( T&& v ); template<typename T> inline typename std::enable_if<!boost::is_float<T>::value, int>::type foo( T&& v ) { return 1; } and MSVC 10 is happy to accept this code. This is somewhat unfortunate since I hoped to use boost::enable_if across compilers. Gennadiy

4 5

[mpl] Strange error using boost::mpl::eval_if
by Edward Diener 12 Nov '12

12 Nov '12

No doubt I have had some sort of C++ brain blockage but the following code using boost::mpl::eval_if gives an error and I cannot see how this would be. This is a simplified case of a more serious problem. --------------------------------------------------------------- #include <boost/mpl/bool.hpp> #include <boost/mpl/eval_if.hpp> template<class T,class C> struct AAA { static const bool value=true; typedef boost::mpl::bool_<value> type; }; template<class T> struct CCC { static const bool value=true; typedef boost::mpl::bool_<value> type; }; template<class T> struct BBB : CCC<T> { }; template<class T1,class T2,class T3,class T4> struct DDD : boost::mpl::eval_if < boost::mpl::false_, BBB<T1>, AAA<int,int> > { }; template < class T1, class T2 = int, class T3 = int, class T4 = int > struct EEE : DDD<T1,T2,T3,T4> { }; int main() { bool result = EEE<int,int>::value; return(result ? 1 : 0); } ----------------------------------------------------------------------- Compiling with gcc 4.6.0 in MingW under Windows I get: test_has_mem_fun.cpp: In function 'int main()': test_has_mem_fun.cpp:50:17: error: 'value' is not a member of 'EEE<int, int>' "g++" -ftemplate-depth-128 -O0 -fno-inline -Wall -pedantic -g -Wno-variadic-macros -std=c++0x -DBOOST_ALL_NO_LIB=1 -I"..\..\.." -c -o "..\..\..\bin.v2\libs\tti\test\test_has_mem_fun.test\gcc-mingw-4.6.0\debug\test_has_mem_fun.o" "test_has_mem_fun.cpp" ----------------------------------------------------------------------- I must be overlooking something obvious but I cannot see it. Any help showing me what is wrong would be appreciated.

3 3

[iterator] [property_map] Enhancement proposals
by Louis Dionne 12 Nov '12

12 Nov '12

Dear boost, First of all, let me quickly introduce myself as this is my first post here: I am a 20 years old programming enthusiast with interest for metaprogramming, functional programming and library design. I also have a strong will to contribute to open source projects since I love the philosophy behind it and it is a great way to develop new skills and to work with talented people. The object of this message is to collect feedback on several enhancement proposals I have prepared for two existing libraries: [boost.iterator] [boost.iterator.accessor_iterator] The accessor_iterator is an iterator adaptor that returns a reference to a member of its pointee when dereferenced. I see it as another step in the direction of easier iterator composition, which has helped me writting less code in the past. [boost.iterator.chained_output_iterator] The chained_output_iterator is an iterator adaptor allowing to apply a functional transformation to a value before outputing it into another output iterator. It is much like a function_output_iterator that would forward its result to another output iterator. It allows for cool stuff like creating a pipeline of operations without having to create temporary storage. [boost.property_map] [boost.property_map.accessor_property_map] The accessor_property_map is a property map returning a reference to a member of the key it is given. It is much like the accessor_iterator for property maps. [boost.property_map.chained_property_map] The chained_property_map is a tool for property map composition. It takes two property maps and uses a value in the first one as a key in the second one to perform its put, get, and operator[] operations. [boost.property_map.property_traits] I feel like the boost/property_map/property_map.hpp header is a little bit bloated and not quite as modular as it could be. For now, I propose that we move the code dealing with property_traits into the boost/property_map/property_traits.hpp header and that we provide metafunctions to check for adherence to property map types. By providing an include in the boost/property_map/property_map.hpp header, backward compatibility is maintained and we simply increase modularity. All the code is available on github: https://github.com/ldionne/boost-submissions To see how each class can be used, you may look at the unit tests for the corresponding class. If anything is accepted, I will be pleased to write documentation and examples for the concerned feature and to integrate it into the existing documentation. Looking forward to your feedback, Louis Dionne

2 11

Re: [boost] hierarchy_tree container
by Morgan Freeberg 10 Nov '12

10 Nov '12

Okay thanks Jose, that helps. My search through the libraries did not pick up on these. By the time I did that I already had the application behavior I wanted, so on my end this has been a refactoring process; I can take a look at these and see if I did that the right way, or if perhaps these could've provided the functionality I need. >From skimming over the documentation, my initial impression is that they're both very cool implementations which might help me in future work, but some of what I did here is falling somewhat outside of that is provided by these. If you're still interested, I can provide an approximation of the challenges met here: 1. From a rather large not-quite-completely-standard XML file, I needed to parse from top to bottom, understanding the structure being created as containers are declared, sub-containers & leafs are added in, and each construct is eventually terminated. The process that does this would need to store not only the instantiation of the tree container, but a vector/array of references to the ancestors of some "current node" being built. That is so that, as it encounters terminating tags, the internal logic can say...this is ended, now this is ended, now this is ended...essentially so that it can "outdent" again. I can see with treetree and st_tree this is do-able if I write some level of intermediate code that builds such an array and maintains it, as I know lots of "standard" XML readers already do. (This I know from my attempts to find one I could actually use in my project.) The issue that would arise here is, I'd still need to write and test that code, and the result would in turn be redundant with what I did here...so it seems these two libraries recognize the same structure mine does, but the scope of purpose is a little bit different. My container internalizes all this parentage information so that when you're reading data sequentially in this way, the client code only needs to track the depth by way of counting the opening and closing tags, then make a call to the container that essentially says "add this, at this depth." Implication being: As a child of whatever. The container internally tracks the concept of "we are currently defining children of so-and-so." 2. In a configuration file of my own making, I needed to pre-declare what the tree should look like. This is not XML, it's a list of statements that say "that class we already defined on line 3, here on line 9 we are defining a class that is a child of that." The method described above that is good for reading these pseudo-XML files, it would not work for that. What is needed here is either a sequential or random-access search by name...In this case you need to write code on top of my container, as well as on top of treetree and s_tree. So in this requirement, all three provide the same functionality. 3. I chose an enumerator/callback interface that works by way of numeric return codes, because I needed it for a variety of commands to be executed on the trees -- some do searches, some validate, some filter (search without terminate after find), et al. The point to dynamically constructing a tree was to be able to do integrity checks on it, and then execute some different application behavior on each node within what I could be sure was the same tree as what I had seen before. So for my particular implementation this is a big benefit, because I can use a chain-of-responsibility design pattern to associate each command with a name, an invoker, some help text, and then a callback routine that defines the behavior. Again, it seems those other two containers can meet the requirement, after intermediate code has been written to adapt them to this application-specific purpose, which in turn has been internalized in my container. Much shorter version: Enum/callback pair for listing the contents of the tree, with numeric return codes; two distinctly separate methods for getting the data in at run-time, one method for reading a streaming mechanism such as XML, the other method for specifically identifying the parent of a new node -- "child of that guy, you made before, over there." The test program I provided mixes those two methods up, so that it is demonstrated they can both work on the same container once it is instantiated. I'll run some tests with these and, if you're interested, provide you with a more fully-informed report on where there may & may not be full redundancy.

1 0

filesystem::path passed to GTest's assertion leads to stack overflow because of infinite recursion
by Andrey Upadyshev 10 Nov '12

10 Nov '12

Hi all, I found an interesting bug with 'filesystem::path' used with GTest: https://svn.boost.org/trac/boost/ticket/7564 I just want to discuss the design of 'path' class which iterator contains the 'path' itself. Don't you think it's nice to fix thing? Best regards, Andrey Upadyshev P.S. Sorry if this is wrong mailing list. Just let me know and I'll repost the message to boost-users <boost-users(a)lists.boost.org> mailing list.

2 5

[type_traits] templated type traits?
by Lorenzo Caminiti 10 Nov '12

10 Nov '12

Hi, Is there a way to inspect if a type is a template instantiaton (is_templated) and the type of the instantiated template parameters (arg1_type)? is_templated< std::vector<int> >::value // true is_templated< int >::value // false template_traits< std::vector<int> >::arg1_type // int Thanks, --Lorenzo

5 5

[wave] add_macro_definition("TEST=") behaves different than #define TEST
by Klaus Gütter 10 Nov '12

10 Nov '12

Test1 posted below produces: INT SPACE EOF SPACE IDENTIFIER SEMICOLON NEWLINE EOF While Test2 produces: INT SPACE IDENTIFIER SEMICOLON NEWLINE EOF The EOF in the third line of Test1 output is produced by the TEST macro expansion. If this expected behaviour? I found this surprising. (MSVC10, Boost 1.51) Regards, Klaus ---- Code: typedef cpplexer::lex_token<> token_type; typedef context< string::iterator, cpplexer::lex_iterator<token_type> > lexer_context_type; void Test1() { string instring("int TEST x;\n"); lexer_context_type ctx(instring.begin(), instring.end(), ""); ctx.set_language(language_support(support_c99)); ctx.add_macro_definition("TEST="); for (lexer_context_type::iterator_type it = ctx.begin(); it != ctx.end(); ++it) cout << get_token_name(token_id(*it)) << endl; } void Test2() { string instring("#define TEST\nint TEST x;\n"); lexer_context_type ctx(instring.begin(), instring.end(), ""); ctx.set_language(language_support(support_c99)); for (lexer_context_type::iterator_type it = ctx.begin(); it != ctx.end(); ++it) cout << get_token_name(token_id(*it)) << endl; }

2 2

[type_traits] is_complete<T> possible realization
by Antony Polukhin 09 Nov '12

09 Nov '12

Hi, Yesterday I had a need to detect, is class forward declared or is it complete. Here are some thoughts: template <class T, int Misc> struct is_complete { typedef char false_type; typedef int true_type; template <class T1> static typename boost::enable_if_c<sizeof(T1), true_type>::type test(int); template <class T1> static false_type test(...); enum ENU { value = ( sizeof(test<T>(0)) == sizeof(true_type) )}; }; 'Misc' parameter is required to work around compilers one time instantiation: struct incomplete; template <int N> struct incomplete_template; struct complete{}; struct complete_abstract{ virtual void foo() =0; }; void test(); void foo1() { cout << is_complete<incomplete, __LINE__>::value << is_complete<incomplete_template<0> , __LINE__>::value << is_complete<incomplete_template<1> , __LINE__>::value << is_complete<complete, __LINE__>::value << is_complete<complete_abstract, __LINE__>::value << endl; } struct incomplete{}; template <> struct incomplete_template<0>{}; void foo2() { cout << is_complete<incomplete, __LINE__>::value // Without second template parameter it would be still returning 0 << is_complete<incomplete_template<0> , __LINE__>::value << is_complete<incomplete_template<1> , __LINE__>::value << is_complete<complete, __LINE__>::value << is_complete<complete_abstract, __LINE__>::value << endl; } int main() { foo1(); // Outputs 00011 foo2(); // Outputs 11011 return 0; } I was thinking of changing 'Misc' parameter definition to something like this: template <class T, class... Misc> struct is_complete ; Than it can be used in template functions/classes just like this: template <class T, class... SomeClasses> void test_function() { is_complete<T, SomeClasses..., boost::mpl::int_<__LINE__> >::value; } So, Is there interest in such metafunction? Can somebody give advices how to improve it? (I`m not sure that implementation is portable, I`ve tested it only on GCC-4.6 and CLANG-3.0, MSVC compiler will be available only tomorrow) -- Best regards, Antony Polukhin

6 10

Re: [boost] hierarchy_tree container
by Morgan Freeberg 09 Nov '12

09 Nov '12

> Subject: Re: [boost] hierarchy_tree container > On Tue, Nov 6, 2012 at 5:28 PM, Morgan Freeberg <mkfreeberg(a)hotmail.com> wrote: > > I have the logic for this nicely separated into a header that seems to meet all the Boost coding guidelines, although I know a peer review process would likely yield helpful improvements that aren't immediately obvious to me. The doc file I prepared goes into much greater detail how this all works...would there be interest in looking into such a thing? > > > yes, can you share the doc url ? > http://www.peekinthewell.net/boostsub/hierarchy_tree/

2 2

[datetime] IANA Time Zone Database
by Maxim Yegorushkin 09 Nov '12

09 Nov '12

Hi Boost, I have files with timestamps in various timezones. I would like to be able to convert these timestamps, no matter what timezone they are in (I know the names of the timezones) to UTC timestamps. I looked through datatime library documentation and found date_time_zonespec.csv database which doesn't seem to support the notion of different rules for the same timezone depending on the date. For example, Russia used to have summer time but not any more. Another method seems to be passing a timezone specification string manually, which requires the user to figure what it should be for a particular date. In other words, given a timestamp and its timezone, I would like to be able to convert that timestamp into a UTC timestamp using conversion rules in force at that particular date in the past. Ideally, this would use IANA Time Zone Database or something similar. Is there a facility in boost to do just that? -- Maxim

6 16

C++ announcements coming tomorrow
by Beman Dawes 09 Nov '12

09 Nov '12

Herb Sutter, the Convenor of the ISO C++ Standards Committee, will be making some announcements tomorrow likely to be of interest to C++ developers in general and Boosters in particular. The venue is a talk titled "The Future of C++" at the Microsoft Build Conference. While some of Herb's announcements will be specific to Microsoft, the key C++ initiatives involve Boost and the whole C++ community. Some of the ideas evolved from feedback Herb got at C++Now/BoostCon 2012 last May. I'll post a summary of the announcements tomorrow, but you can also watch the live stream at http://channel9.msdn.com at 12:45 PM Pacific time. For other time zones, see http://www.timeanddate.com/worldclock/fixedtime.html?iso=20121102T1945 --Beman PS: We don't usually post teasers like this on the Boost lists, but Herb asked that a notice be posted, and given the endless work he has put in on this over the summer, I couldn't say no.

22 63

★ Boost, Bruce left a message for you
by Badoo 08 Nov '12

08 Nov '12

Bruce left a message for you Only you can see the sender and content of your message, and you can delete it anytime. You can instantly reply using our message exchange system: http://eu1.badoo.com/tortoise74/in/3i4doZuulPE/?lang_id=3&m=21&mid=509c4330… If the link in this message does not work, try copying and pasting it into your browser. This email is part of our delivery procedure for the message sent by Bruce. If you have received this email by mistake, please ignore it. The message will be deleted soon. Have fun! The Badoo Team You have received this email from Badoo Trading Limited (postal address below). http://eu1.badoo.com/impersonation.phtml?lang_id=3&email=boost%40lists.boos… Badoo Trading Limited is a limited company registered in England and Wales under CRN 7540255 with its registered office at Media Village, 131 - 151 Great Titchfield Street, London, W1W 5BB.

1 0

[test]portability of data test cases and build issues
by Gennadiy Rozenal 08 Nov '12

08 Nov '12

Hi, I've been working on portability fixes for new features in boost.test. They now works fine with gcc 4.6 and 4.7 msvc-10.0 and msvc-11.0. My attempt with clang on linux lead to compiler crashing, but I see it passing in regression on darwin, so I am not sure on the status. I do still have some issues about portability and boost.build: 1. Boost.Build does not handle correctly target foo with sources residing in subdirectory foo under location of Jamfile. I had to rename directory boost/libs/test/test/test_datasets into test_datasets_src, because of that. 2. How do I tell that I want to pass compilation to gcc in toolset gcc-4.7 only? I've tried <toolset>gcc-4.7:<cxxflags>-std=c++11 and <toolset>gcc-4.7.2:<cxxflags>-std=c++11 and either one does not work. <toolset>gcc:<cxxflags>-std=c++11 does work, but I want to pass different options for different versions of gcc. 3. Question: Should I tell *unconditionally* in Boost.Test Jamfile in boost/libs/test/build that I want to pass -std=c++11/-std=c++0x depending on a version? If not, how do I test test_dataset target with this option? Also How do I disable for configurations which does not support it? 4. Issues with regression testers setup? If you look here: http://www.boost.org/development/tests/trunk/developer/test.html You will see that: a) clang linux columns are empty. Why is that? b) msvc-11.0 setup is broken because of: 'cl' is not recognized as an internal or external command, operable program or batch file. c) sun setup is broken because of: /bin/sh: line 2: CC: not found Can we fix these? 5. Portability for other compilers. I am not quite sure which is lowest version of gcc this feature works. Anyone who is interested in making it work with older/different compilers feel free to submit patches. Regards, Gennadiy

5 7

Release branch closed
by Marshall Clow 08 Nov '12

08 Nov '12

Boosters, The release branch is now closed for all commits, except by explicit permission of release managers. -- The Release Managers, Beman Dawes Daniel James Eric Niebler Rene Rivera Vladimir Prus Marshall Clow

4 5

[thread] warning in trunk
by Gennadiy Rozental 08 Nov '12

08 Nov '12

Hi, Can anyone clean this one: boost/thread/future.hpp(378) : warning C4913: user defined binary operator ',' exists but no overload could convert all operands, default built-in binary operator ',' used Gennadiy

5 5

[OT] std::complex warts
by Neal Becker 08 Nov '12

08 Nov '12

std::complex doesn't seem to allow mixing of types in arithmetic operations. This is quite inconvenient for code that is generic on the base float type. For example: template<typename flt_t> flt_t some_function (std::complex<flt_t> z) { return 2. * z / 4.2 + ... } This will fail to compile when flt_t == float (but succeeds for double). casting every constant in a large computation is really not an acceptable option. Thoughts?

3 2

[type_traits] is_convertible<int, int&> inconsistent result
by TONGARI 08 Nov '12

08 Nov '12

Hi, I'd expect boost::is_convertible<int, int&>::value to be false, so I was surprised that it gives me "true" under g++ 4.7.1. Switch to std::is_convertible<int, int&> or using clang instead gives me the expected "false". After some search, I found: https://svn.boost.org/trac/boost/ticket/7251 Any plan to fix it?

2 1

[variant] static_visitor has no virtual destructor.
by Pierre Talbot 08 Nov '12

08 Nov '12

Hello, I have a compilation error with Boost (1.52) and g++ (4.7) with the flag -Weffc++: error: base class ‘class boost::static_visitor<std::basic_string<char> >’ has a non-virtual destructor [-Werror=effc++] And the static_visitor class is defined with a protected non-virtual destructor: template <typename R = ::boost::detail::static_visitor_default_return> class static_visitor : public detail::is_static_visitor_tag { public: // typedefs typedef R result_type; protected: // for use as base class only static_visitor() { } ~static_visitor() { } }; Is it normal ? And if it is, how to avoid this error ? Thank you for your help, Pierre Talbot.

3 3

Adding an option to set the name of a boost::thread
by david.hagood＠gmail.com 07 Nov '12

07 Nov '12

Has any thought been given to allowing a name to be set on a boost::thread, such that (if the underlying implementation supports it) that name would show up in things like top and ps? In Linux, you can name a thread via the prctl() call and it will show up in top - dandy for debugging which of the bazillion threads in my app has decided to suck up all the CPU. I don't know if Windows supports such a call, and IMHO it would be acceptable if the call did nothing in such a case. Ideally, I'd want to see it as a property, something like: void boost::thread::set_name(std::string name) std::string boost::thread::get_name() const;

6 11

[algorithm] Knuth-Morris-Pratt Search docs overly terse
by Jeff Flinn 07 Nov '12

07 Nov '12

I'm not sure if this is intentional but: http://www.boost.org/doc/libs/1_52_0/libs/algorithm/doc/html/the_boost_algo… contains only: Overview The header file 'knuth_morris_pratt.hpp' contains an an implementation of the Knuth-Morris-Pratt algorithm for searching sequences of values. I've created Ticket #7656. Jeff

1 0

[functional] Interested in can_be_called<F, Sig> metafunction?
by TONGARI 07 Nov '12

07 Nov '12

Hi there, I've used this metafunction for some time, and it just fitted my need. Recently, I make up my mind to complete it, willing to put it in public. Synopsis -------------- can_be_called<F, Sig> F Any callable type to test, even member-function ptr. Sig The desired calling signature, function-type only. Example ------------- struct X; struct F { void operator()(); }; can_be_called<void(int), void(char)>::type // mpl::true_ can_be_called<int(), void()>::type // mpl::true_, return val can always be discarded can_be_called<int(), int&()>::type // mpl::false_, cannot return as reference can_be_called<void(int&), void(int)>::type // mpl::false_, cannot accept rvalue can_be_called<void(), void(*)()>::type // compile error, "void(*)()" not a function-type can_be_called<F, void()>::type // mpl::true_ can_be_called<F const, void()>::type // mpl::false_, F::operator() is non-const can_be_called<void(X::*)(), void()>::type // mpl::true_, only the signature part is concerned can_be_called<void(X::*)(), void(X*)>::type // mpl::false_, implicit 'this' arg not accounted Repository ---------------- https://github.com/jamboree/boost.functional test files provided, compile well on g++ 4.7.1 & clang 3.2 No docs are written (yet), if you're interested, please let me know and I'll prepare for review or something... Comments are welcome :)

6 19

[1.52] PDF Documentation build available
by John Maddock 07 Nov '12

07 Nov '12

The PDF build of Boost docs is now available for 1.52 from: https://sourceforge.net/projects/boost/files/boost-docs/1.52.0/ John.

1 0

[qvm] scalar_cast
by Nikolay Mladenov 07 Nov '12

07 Nov '12

Hi Emil, I am trying qvm in a small project that uses complex numbers and have expressions of the kind : cv3 = c1*rv3_1 + c2*rv3_2 (the v3's are vectors, the c's are complex and the r's are real). I wrote it as : cv3 = scalar_cast<complex>(rv3_1)*c1 + scalar_cast<complex>(rv3_2)*c2; but this seems to invoke 6 complex constructors (unnecessarily) I have not tested to see if the constructors will be optimized away, but it seems to me that if : v_traits<vector_scalar_cast_>::scalar_type == complex , bit v_traits<vector_scalar_cast_>::r/ir return real the expression will compile and no complex constructors will be invoked. It seems to me that there is a need for another kind of scalar_cast that just adapts the v_traits<>:scalar_type but leaves the r() and ir() unchanged Another question I have is if there is a reason why vector*scalar works but scalar*vector does not? Thanks in advance, Nikolay PS I can send patches if you'd like.

2 3

[release][1.52.0] Release Notes
by Daniel James 06 Nov '12

06 Nov '12

Hello everyone, We're coming up to the beta release, so it's time to put together the release notes (although please don't feel you need to wait for me to start). As always you can send them to me, or if you want update them yourself in subversion. The files are at: https://svn.boost.org/svn/boost/website/public_html/live/feed/history/ The actual site won't get updated until I run the update script. You can see the release notes so far at: http://www.boost.org/users/history/version_1_52_0.html As usual, they're not finished yet, and some of the links might not work as the 1.52 documentation won't be uploaded until after the beta is released. thanks, Daniel

9 22

[clang] Windows toolset support?
by Beman Dawes 06 Nov '12

06 Nov '12

Cygwin has been shipping clang for six months or so. Has anyone gotten the cygwin/clang distribution (or any other clang distribution) to build boost? What toolset did you use? What does your user-config.jam file look like? Do you run bjam/b2 from the Windows command line or the bash command line? Thanks, --Beman

7 16

make_shared_array
by Peter Dimov 06 Nov '12

06 Nov '12

Hello, Glen Fernandes has kindly contributed an implementation of make_shared_array and allocate_shared_array. These are like make_shared and allocate_shared, except that they take a size_t argument N and allocate an array of N elements. Glen has made the functions return a shared_ptr, mostly because they are non-intrusive and it's not possible to return a shared_array without changes to shared_ptr and shared_array. But we can make such changes when we put the functions in Boost. So the question is, should we? It makes almost no sense to have a function called make_shared_array that does not, in fact, make a shared_array. On the other hand, Glen posits that some people may prefer to use shared_ptr instead of shared_array in their code for various reasons, one of which is that shared_array's default constructor can throw. Opinions?

9 40

hierarchy_tree container
by Morgan Freeberg 06 Nov '12

06 Nov '12

Ready to assess the level of interest and look into the possibility of a preliminary submission on my container library. I needed something to organize objects of type T, into a simple tree with parent-child relationships, which could then be filtered and listed. Also needed the container to maintain a "current add" position if you will, much like an output file stream, so I could feed tree structure data into it, for example as when reading from XML. I have the logic for this nicely separated into a header that seems to meet all the Boost coding guidelines, although I know a peer review process would likely yield helpful improvements that aren't immediately obvious to me. The doc file I prepared goes into much greater detail how this all works...would there be interest in looking into such a thing?

2 1

[type_traits] possible regression on is_function trait
by Vicente J. Botet Escriba 06 Nov '12

06 Nov '12

Hi, I don't know if this is a regression on Boost.TypeTraits or if I'm using incorrectly the is_function trait. John, could you confirm there is a bug in is_function? Best, Vicente Test output: Sandia-darwin-4.4 - thread - async__async_p / darwin-4.4 Rev 81191 / Mon, 5 Nov 2012 06:30:00 +0000 *Report Time: *Mon, 5 Nov 2012 14:19:58 +0000 Compile [2012-11-05 07:50:44 UTC]: fail "/opt/local/bin/g++-mp-4.4" -ftemplate-depth-128 -O0 -fno-inline -Wall -pedantic -g -dynamic -gdwarf-2 -fexceptions -fPIC -Wextra -Wno-long-long -fpermissive -pedantic -DBOOST_ALL_NO_LIB=1 -DBOOST_CHRONO_DYN_LINK=1 -DBOOST_SYSTEM_DYN_LINK=1 -DBOOST_SYSTEM_NO_DEPRECATED -DBOOST_THREAD_BUILD_DLL=1 -DBOOST_THREAD_POSIX -DBOOST_THREAD_THROW_IF_PRECONDITION_NOT_SATISFIED -DBOOST_THREAD_USE_DLL=1 -I".." -c -o "/Volumes/scratch/kbelco/boost/results/boost/bin.v2/libs/thread/test/async__async_p.test/darwin-4.4/debug/threading-multi/sync/futures/async/async_pass.o" "../libs/thread/test/sync/futures/async/async_pass.cpp" In file included from ../boost/type_traits/is_convertible.hpp:28, from ../boost/thread/detail/move.hpp:13, from ../boost/thread/future.hpp:20, from ../libs/thread/test/sync/futures/async/async_pass.cpp:28: ../boost/type_traits/is_function.hpp: In instantiation of 'boost::detail::is_function_chooser<false>::result_<boost::rv<boost::rv<boost::packaged_task<int()> > >&>': ../boost/type_traits/is_function.hpp:60: instantiated from 'boost::detail::is_function_impl<boost::rv<boost::rv<boost::packaged_task<int()> > >&>' ../boost/type_traits/is_function.hpp:102: instantiated from 'boost::is_function<boost::rv<boost::rv<boost::packaged_task<int()> > >&>' ../boost/type_traits/is_convertible.hpp:354: instantiated from 'const bool boost::detail::is_convertible_impl<boost::rv<boost::packaged_task<int()> >&, boost::rv<boost::rv<boost::packaged_task<int()> > >&>::value' ../boost/type_traits/is_convertible.hpp:480: instantiated from 'boost::is_convertible<boost::rv<boost::packaged_task<int()> >&, boost::rv<boost::rv<boost::packaged_task<int()> > >&>' ../boost/thread/future.hpp:2717: instantiated from 'boost::future<T> boost::async(boost::launch, R (*)()) [with R = int]' ../libs/thread/test/sync/futures/async/async_pass.cpp:117: instantiated from here ../boost/type_traits/is_function.hpp:52: error: forming pointer to reference type 'boost::rv<boost::rv<boost::packaged_task<int()> > >&'

3 5

[test] BOOST_TEST - universal testing tool
by Gennadiy Rozental 06 Nov '12

06 Nov '12

Hi, Based on a discussion on mini-review thread I make some changes to the universal testing tool interface and now it look as follows (similar interfaces on WARN and REQUIRE levels): BOOST_CHECK_ASSERTION(A) - new expression template based testing tool BOOST_TEST(A,M) := BOOST_CHECK_ASSERTION(A) if M is not supplied or BOOST_CHECK_MESSAGE(A,M) if M is supplied. BOOST_TEST (and it's siblings BOOST_TEST_WARN and BOOST_TEST_REQUIRE) is intended to become a primary (only?) testing tools from now on. It replaces and deprecates right away following tools: BOOST_CHECK BOOST_CHECK_MESSAGE BOOST_CHECK_EQUAL, BOOST_CHECK_NE, BOOST_CHECK_LT, BOOST_CHECK_LE, BOOST_CHECK_GT, BOOST_CHECK_GE There are still some tools which are not directly replaceable. I have some ideas how we can get there, but your input is appreciated: 1. BOOST_CHECK_THROW, BOOST_CHECK_EXCEPTION, BOOST_CHECK_NO_THROW We can probably leave these as is. Alternatively we'll need to postpone expression evaluation with separate BOOST_TEST_DELAYED tool. We also need to introduce special tags unit_test::throws, unit_test::no_throw: BOOST_TEST_DELAYED(foo(), unit_test::throws<my_exception>() ); BOOST_TEST_DELAYED(foo(), unit_test::throws<my_exception>(predicate) ); BOOST_TEST_DELAYED(foo(), unit_test::throws( my_exception(...) ) ); BOOST_TEST_DELAYED(foo(), unit_test::no_throw() ); Later form will match to exact exception value. We might be able to fit into BOOST_TEST interface, but that would require somehow we need to recognize executable entity as special case: BOOST_TEST( foo, unit_test::throws<my_exception>() ); Not quite sure if this is possible. 2. BOOST_CHECK_CLOSE, BOOST_CHECK_CLOSE_FRACTION, BOOST_CHECK_SMALL We can deal with these by introducing couple special tags: BOOST_TEST(a == 1.5, unit_test::tolerance(1e-6) ); BOOST_TEST(a == 0.003, unit_test::percent_tolerance(1e-6) ); BOOST_TEST(a, unit_test::small(1e-3) ); On a plus side we'll be able to use these in new previously unavailable way: BOOST_TEST(a > 1.1, unit_test::tolerance(1e-6) ); This would test that value of a either > 1.1 or within a fraction tolerance of it. 3. BOOST_CHECK_PREDICATE Similar to (1) we need to delay predicate execution. Might be easier to leave it be. 4. BOOST_CHECK_EQUAL_COLLECTIONS I think using overloading of equality comparisons we should be able to support this directly: BOOST_TEST( expr == std::vector<int>{1,2,3,4}); 5. BOOST_CHECK_BITWISE_EQUAL We can introduce yet another tag to deal with this: BOOST_TEST(a == 0xA1FB, unit_test::bitwise ); As usual any comments are welcome. Gennadiy

7 16

[locale] [filesystem] Windows local 8 bit encoding
by Thiel, Bjoern 06 Nov '12

06 Nov '12

Hi, developing platform independent code I really like the convenience functions conv::to_utf, conv::from_utf, and conv::utf_to_utf from locale. Why not add something like conv::local8bit_to_utf and conv::local8bit_from_utf following the rational from filesystem (path encoding conversions): template < typename CharType > std::basic_string< CharType > local8bit_to_utf ( std::string const & text, method_type how = default_method ) { char const * encoding = impl::local8bit_encoding() ; return to_utf< CharType >( text, encoding, how ) ; } template< typename CharType > std::string local8bit_from_utf ( std::basic_string< CharType > const & text, method_type how = default_method ) { char const * encoding = impl::local8bit_encoding() ; return from_utf< CharType >( text, encoding, how ) ; } with char const * local8bit_encoding() { #ifdef WIN32 UINT codepage = AreFileApisANSI() ? GetACP() : GetOEMCP() ; return windows_codepage_to_encoding( codepage ) ; #else return "UTF-8" ; #endif } and with (better using a map) char const * windows_codepage_to_encoding( int const codepage ) { switch (codepage) { case 874: return "windows-874" ; case 932: return "Shift_JIS" ; // but should be "Windows-31J" ; case 936: return "GB2312" ; case 949: return "KS_C_5601-1987" ; case 950: return "Big5" ; case 1250: return "windows-1250" ; case 1251: return "windows-1251" ; case 1252: return "windows-1252" ; case 1253: return "windows-1253" ; case 1254: return "windows-1254" ; case 1255: return "windows-1255" ; case 1256: return "windows-1256" ; case 1257: return "windows-1257" ; case 1258: return "windows-1258" ; case 20127: return "US-ASCII" ; case 20866: return "KOI8-R" ; case 20932: return "EUC-JP" ; case 21866: return "KOI8-U" ; case 28591: return "ISO-8859-1" ; case 28592: return "ISO-8859-2" ; case 28593: return "ISO-8859-3" ; case 28594: return "ISO-8859-4" ; case 28595: return "ISO-8859-5" ; case 28596: return "ISO-8859-6" ; case 28597: return "ISO-8859-7" ; case 28598: return "ISO-8859-8" ; case 28599: return "ISO-8859-9" ; case 28603: return "ISO-8859-13" ; case 28605: return "ISO-8859-15" ; case 50220: return "ISO-2022-JP" ; case 50225: return "ISO-2022-KR" ; case 51949: return "EUC-KR" ; case 54936: return "GB18030" ; case 65001: return "UTF-8" ; default: { std::ostringstream message ; message << "Unknown codepage " << codepage ; throw std::invalid_argument( message.str() ) ; } } } Best regards Bjoern.

5 10

[geometry] Can't build docs?
by John Maddock 06 Nov '12

06 Nov '12

I'm trying to build the PDF of the geometry docs for the 1.52 release, but the build is failing: warning: Tag `SHOW_DIRECTORIES' at line 162 of file Doxyfile has become obsolete. To avoid this warning please remove this line from your configuration file or upgrade it using "doxygen -u" warning: Tag `HTML_ALIGN_MEMBERS' at line 257 of file Doxyfile has become obsolete. To avoid this warning please remove this line from your configuration file or upgrade it using "doxygen -u" M:/data/boost/branches/release/boost/geometry/strategies/spherical/distance_haversine.hpp:106: warning: found </em> at different nesting level (7) than expected (4) M:/data/boost/branches/release/boost/geometry/strategies/spherical/distance_haversine.hpp:107: warning: found </em> at different nesting level (7) than expected (4) M:/data/boost/branches/release/boost/geometry/strategies/spherical/distance_haversine.hpp:113: warning: end of comment block while expecting command </em> M:/data/boost/branches/release/boost/geometry/strategies/spherical/distance_haversine.hpp:113: warning: end of comment block while expecting command </em> M:/data/boost/branches/release/boost/geometry/strategies/spherical/distance_haversine.hpp:106: warning: found </em> at different nesting level (7) than expected (4) M:/data/boost/branches/release/boost/geometry/strategies/spherical/distance_haversine.hpp:107: warning: found </em> at different nesting level (7) than expected (4) M:/data/boost/branches/release/boost/geometry/strategies/spherical/distance_haversine.hpp:113: warning: end of comment block while expecting command </em> M:/data/boost/branches/release/boost/geometry/strategies/spherical/distance_haversine.hpp:113: warning: end of comment block while expecting command </em> warning: mismatched versions of Boost.Build engine and core warning: Boost.Build engine (M:\data\boost\branches\release\b2.exe) is 2011.04.00 warning: Boost.Build core (at M:/data/boost/branches/release/tools/build/v2) is 2011.12-svn ...patience... ...found 318 targets... ...updating 3 targets... quickbook.quickbook-to-boostbook ..\..\..\bin.v2\libs\geometry\doc\msvc-10.0\debug\threading-multi\geometry.xml Generating Output File: ..\..\..\bin.v2\libs\geometry\doc\msvc-10.0\debug\threading-multi\geometry.xml generated/get.qbk:32: error: Syntax Error near column 2. generated/get.qbk:32: error: Syntax Error near column 3. generated/get.qbk:32: error: Syntax Error near column 3. generated/get.qbk:69: error: Syntax Error near column 2. generated/get.qbk:69: error: Syntax Error near column 3. generated/get.qbk:69: error: Syntax Error near column 3. Error: Error count: 6. Any ideas? BTW I see the same failures on Trunk and release branches. Thanks, John.

1 0

[array] compile-time checked access
by Tobias Loew 06 Nov '12

06 Nov '12

Hi, I was just rewriting some old code with hard coded indices for array access and though that compile-time checked access to array elements would be a nice thing. Maybe there are smart compilers out there that emit warnings or errors for a hard coded out-of-bounds access, but my compiler does not. So, code like compiles without warnings or erros. Now, adding the following functions to array would make it possible to write which results in the expected error messages. Tobias -- View this message in context: http://boost.2283326.n4.nabble.com/array-compile-time-checked-access-tp4638… Sent from the Boost - Dev mailing list archive at Nabble.com.

5 8

shared_ptr<X[5]>
by Peter Dimov 06 Nov '12

06 Nov '12

Now that we (are going to) have shared_ptr<X[]>, what should shared_ptr<X[5]> do? >From user point of view, it seems obvious that this is as good a pointer to an array as shared_ptr<X[]> is, so it should behave similarly, having op[] and an element_type of X. >From a generic point of view, this could potentially break code that assumes that shared_ptr<T>::get() always returns a T*, even when T is X[5]. But how common is such a scenario? On the other hand, it will actually _fix_ generic code of the form shared_ptr<T> p( new T ); when T is X[5].

2 1

Re: [boost] C++ announcements coming tomorrow
by Brian Wood 05 Nov '12

05 Nov '12

From: Paul Mensonides > In that last announcement talk alone together with the follow-up Q & A > there are numerous "subtle" bits of marketing. The entire general trend > is one of attempting to turn a product (software) into a service. That > is an anti-consumer nickle-and-dime model which is just as anti-consumer > as trying to trick people that can't afford something into making > payments. It is just as anti-consumer as many other related things > occurring in the software industry nowadays--microtransactions being one > of them. I bet MS investors would think differently. Is there another option available to them than services? -- Brian Wood Ebenezer Enterprises -- so far G-d has helped us. http://webEbenezer.net

2 1

Boost mpi, serialization and shared_ptr
by Gabriel 05 Nov '12

05 Nov '12

Hello, Has this problem been solved? I have the same problems, I have a class with a shared_ptr member which does not compile with MPI skeleton and content. I receive the same error: *class boost::mpi::packed_skeleton_* *iarchive' has no member named 'reset' *and so on (I refere to the older posts) Thanks for any reply! BR Gabriel Nützi

1 0

[iterator] Library name (was [website] Wrong library name)
by Daniel James 04 Nov '12

04 Nov '12

On 4 November 2012 07:51, Michel Morin <mimomorin(a)gmail.com> wrote: > Boost.Iterator is listed as "Iterators" (note the plural form) in > > * http://www.boost.org/doc/libs/ > * trunk/boost/libs/libraries.htm > > But it should be "Iterator". I'll fix this in a sec, although 'libs/libraries' will only be updated in 1.53. I replied with an 'iterator' subject so that the appropriate people might see this.

2 2

Help! Detecting that two template aliases are equal.
by Matt Calabrese 04 Nov '12

04 Nov '12

In working on Boost.Generic I need, in multiple parts of the library, to detect if two template aliases are equivalent. For instance, this is required when comparing the compatibility of an automatically generated concept map of a less-refined concept with an explicitly created concept map for the less-refined concept when the concept in question has an associated class template. This seems like it shouldn't be too difficult, but apparently my understanding of template aliases is incomplete: //////////////////// // Create a template template< class > struct template_ {}; // Make a simple alias of the template template< class A > using template_alias = template_< A >; // Create a metafunction to determine if two unary type templates are the same template< template< class > class L, template< class > class R > struct templates_are_the_same { static bool constexpr value = false; }; template< template< class > class T > struct templates_are_the_same< T, T > { static bool constexpr value = true; }; // In Clang and GCC, the following static_assert will be triggered static_assert( templates_are_the_same< template_, template_alias >::value , "Templates are not the same." ); //////////////////// This behavior is observed in both Clang and GCC, though I haven't verified that it is correct behavior in the standard. Assuming that it is in fact standard, can anyone conceive of a way around this limitation? I've considered passing dummy arguments to the templates based on the template parameter list and checking that the resultant types are equal, but I'd like to avoid that if at all possible, since it seems like it would be difficult or impossible to support certain templates properly (I.E. consider the template parameter list of a template where one parameter type is dependent on another, like std::integral_constant). This type of detection is very important in making Boost.Generic work as closely to N2914 as possible so any workaround, however hairy, would be a huge help. -- -Matt Calabrese

5 8

[test] linking issues on trunk
by Vicente J. Botet Escriba 04 Nov '12

04 Nov '12

Hi, I have found some linking issues (see bellow) with Boost.Test ubuntu gcc-4.4.6,gcc-4.6.1.0(c++0x),intel-12.1.3.0(c++0x). I'm linking with boost_unit_test_framework. Should other libraries be added? Best, Vicente P.S. This worked well before. time bjam --build-dir=/tmp/bin.v2 toolset=gcc-4.4.6,gcc-4.6.1.0x,intel-12.1.3.0x -q -d2 gcc.link /tmp/bin.v2/boost/bin.v2/libs/thread/test/test_thread.test/gcc-4.4.6/debug/threading-multi/test_thread "g++-4.4" -Wl,-R -Wl,"/tmp/bin.v2/boost/bin.v2/libs/chrono/build/gcc-4.4.6/debug/threading-multi" -Wl,-R -Wl,"/tmp/bin.v2/boost/bin.v2/libs/system/build/gcc-4.4.6/debug/threading-multi" -Wl,-R -Wl,"/tmp/bin.v2/boost/bin.v2/libs/thread/build/gcc-4.4.6/debug/threading-multi" -Wl,-rpath-link -Wl,"/tmp/bin.v2/boost/bin.v2/libs/chrono/build/gcc-4.4.6/debug/threading-multi" -Wl,-rpath-link -Wl,"/tmp/bin.v2/boost/bin.v2/libs/system/build/gcc-4.4.6/debug/threading-multi" -Wl,-rpath-link -Wl,"/tmp/bin.v2/boost/bin.v2/libs/thread/build/gcc-4.4.6/debug/threading-multi" -o "/tmp/bin.v2/boost/bin.v2/libs/thread/test/test_thread.test/gcc-4.4.6/debug/threading-multi/test_thread" -Wl,--start-group "/tmp/bin.v2/boost/bin.v2/libs/thread/test/test_thread.test/gcc-4.4.6/debug/threading-multi/test_thread.o" "/tmp/bin.v2/boost/bin.v2/libs/chrono/build/gcc-4.4.6/debug/threading-multi/libboost_chrono.so.1.52.0" "/tmp/bin.v2/boost/bin.v2/libs/test/build/gcc-4.4.6/debug/link-static/threading-multi/libboost_unit_test_framework.a" "/tmp/bin.v2/boost/bin.v2/libs/thread/build/gcc-4.4.6/debug/threading-multi/libboost_thread.so.1.52.0" "/tmp/bin.v2/boost/bin.v2/libs/system/build/gcc-4.4.6/debug/threading-multi/libboost_system.so.1.52.0" -Wl,-Bstatic -Wl,-Bdynamic -lrt -Wl,--end-group -g -pthread /tmp/bin.v2/boost/bin.v2/libs/test/build/gcc-4.4.6/debug/link-static/threading-multi/libboost_unit_test_framework.a(unit_test_main.o): In function `boost::unit_test::unit_test_main(boost::unit_test::test_suite* (*)(int, char**), int, char**)': /mnt/boost/trunk/libs/thread/test/../../../boost/test/impl/unit_test_main.ipp:92: undefined reference to `boost::unit_test::traverse_test_tree(unsigned long, boost::unit_test::test_tree_visitor&, bool)' /tmp/bin.v2/boost/bin.v2/libs/test/build/gcc-4.4.6/debug/link-static/threading-multi/libboost_unit_test_framework.a(framework.o): In function `boost::unit_test::framework::impl::apply_filters(unsigned long)': /mnt/boost/trunk/libs/thread/test/../../../boost/test/impl/framework.ipp:506: undefined reference to `boost::unit_test::traverse_test_tree(unsigned long, boost::unit_test::test_tree_visitor&, bool)' /mnt/boost/trunk/libs/thread/test/../../../boost/test/impl/framework.ipp:533: undefined reference to `boost::unit_test::traverse_test_tree(unsigned long, boost::unit_test::test_tree_visitor&, bool)' /mnt/boost/trunk/libs/thread/test/../../../boost/test/impl/framework.ipp:537: undefined reference to `boost::unit_test::traverse_test_tree(unsigned long, boost::unit_test::test_tree_visitor&, bool)' /mnt/boost/trunk/libs/thread/test/../../../boost/test/impl/framework.ipp:548: undefined reference to `boost::unit_test::traverse_test_tree(unsigned long, boost::unit_test::test_tree_visitor&, bool)' /tmp/bin.v2/boost/bin.v2/libs/test/build/gcc-4.4.6/debug/link-static/threading-multi/libboost_unit_test_framework.a(framework.o):/mnt/boost/trunk/libs/thread/test/../../../boost/test/impl/framework.ipp:603: more undefined references to `boost::unit_test::traverse_test_tree(unsigned long, boost::unit_test::test_tree_visitor&, bool)' follow /tmp/bin.v2/boost/bin.v2/libs/test/build/gcc-4.4.6/debug/link-static/threading-multi/libboost_unit_test_framework.a(framework.o): In function `visit': /mnt/boost/trunk/libs/thread/test/../../../boost/test/impl/framework.ipp:686: undefined reference to `boost::unit_test::decorator::for_test_unit::apply(boost::unit_test::test_unit&)' /tmp/bin.v2/boost/bin.v2/libs/test/build/gcc-4.4.6/debug/link-static/threading-multi/libboost_unit_test_framework.a(framework.o): In function `boost::unit_test::framework::init(boost::unit_test::test_suite* (*)(int, char**), int, char**)': /mnt/boost/trunk/libs/thread/test/../../../boost/test/impl/framework.ipp:691: undefined reference to `boost::unit_test::traverse_test_tree(unsigned long, boost::unit_test::test_tree_visitor&, bool)' /mnt/boost/trunk/libs/thread/test/../../../boost/test/impl/framework.ipp:698: undefined reference to `boost::unit_test::traverse_test_tree(unsigned long, boost::unit_test::test_tree_visitor&, bool)' /tmp/bin.v2/boost/bin.v2/libs/test/build/gcc-4.4.6/debug/link-static/threading-multi/libboost_unit_test_framework.a(framework.o): In function `boost::unit_test::framework::run(unsigned long, bool)': /mnt/boost/trunk/libs/thread/test/../../../boost/test/impl/framework.ipp:1008: undefined reference to `boost::unit_test::traverse_test_tree(unsigned long, boost::unit_test::test_tree_visitor&, bool)' /mnt/boost/trunk/libs/thread/test/../../../boost/test/impl/framework.ipp:1045: undefined reference to `boost::unit_test::traverse_test_tree(unsigned long, boost::unit_test::test_tree_visitor&, bool)' /tmp/bin.v2/boost/bin.v2/libs/test/build/gcc-4.4.6/debug/link-static/threading-multi/libboost_unit_test_framework.a(framework.o): In function `boost::unit_test::ut_detail::label_filter::visit(boost::unit_test::test_unit const&)': /mnt/boost/trunk/libs/thread/test/../../../boost/test/impl/framework.ipp:217: undefined reference to `boost::unit_test::test_unit::has_label(boost::unit_test::basic_cstring<char const>) const' /tmp/bin.v2/boost/bin.v2/libs/test/build/gcc-4.4.6/debug/link-static/threading-multi/libboost_unit_test_framework.a(framework.o): In function `boost::unit_test::ut_detail::remove_disabled::visit(boost::unit_test::test_unit const&)': /mnt/boost/trunk/libs/thread/test/../../../boost/test/impl/framework.ipp:300: undefined reference to `boost::unit_test::traverse_test_tree(unsigned long, boost::unit_test::test_tree_visitor&, bool)' /tmp/bin.v2/boost/bin.v2/libs/test/build/gcc-4.4.6/debug/link-static/threading-multi/libboost_unit_test_framework.a(progress_monitor.o): In function `boost::unit_test::traverse_test_tree(boost::unit_test::test_unit const&, boost::unit_test::test_tree_visitor&, bool)': /mnt/boost/trunk/libs/thread/test/../../../boost/test/tree/traverse.hpp:46: undefined reference to `boost::unit_test::traverse_test_tree(boost::unit_test::test_case const&, boost::unit_test::test_tree_visitor&, bool)' /mnt/boost/trunk/libs/thread/test/../../../boost/test/tree/traverse.hpp:48: undefined reference to `boost::unit_test::traverse_test_tree(boost::unit_test::test_suite const&, boost::unit_test::test_tree_visitor&, bool)' /tmp/bin.v2/boost/bin.v2/libs/test/build/gcc-4.4.6/debug/link-static/threading-multi/libboost_unit_test_framework.a(results_reporter.o): In function `boost::unit_test::results_reporter::make_report(boost::unit_test::report_level, unsigned long)': /mnt/boost/trunk/libs/thread/test/../../../boost/test/impl/results_reporter.ipp:181: undefined reference to `boost::unit_test::traverse_test_tree(unsigned long, boost::unit_test::test_tree_visitor&, bool)' collect2: ld returned 1 exit status ...failed gcc.link /tmp/bin.v2/boost/bin.v2/libs/thread/test/test_thread.test/gcc-4.4.6/debug/threading-multi/test_thread... ...failed updating 1 target...

2 1

[website] Wrong library name
by Michel Morin 04 Nov '12

04 Nov '12

Boost.Iterator is listed as "Iterators" (note the plural form) in * http://www.boost.org/doc/libs/ * trunk/boost/libs/libraries.htm But it should be "Iterator". Regards, Michel

1 0

[variant] awkward recursion
by Dave Abrahams 03 Nov '12

03 Nov '12

I've been playing around with variant a bit and decided to try to build a data structure for storing json. I came up with several different approaches but none are super-satisfying. I'd like some feedback. (If you need a refresher on what's in json, the front page of http://json.org tells all). In the abstract, json looks like: struct null {}; typedef std::map<std::string, value> object; typedef std::vector<value> array; typedef variant< null, std::string, double, object, array, bool > value; Naturally, this code isn't legal C++, so I set about making it be. The first thing I tried was to use recursive_wrapper<>, as the documentation implies it is the most flexible way to do this sort of thing. Unfortunately, there's no clean way to reformulate this type in a way that allows recursive_wrapper work, because the type that needs to be wrapped in recursive_wrapper includes "value" in its name, and I can't forward-declare it. The only way to forward-declare a type X, as far as I know, is: struct X; // or class X; So to try to get recursive_wrapper to work, I tried a couple of formulations that started with that, but it turns out that when you do this, you end up not needing recursive_wrapper at all struct value; typedef std::map<std::string, value> object; typedef std::vector<value> array; typedef variant< null, std::string, double, object, array, bool > value_base; struct value : value_base { value() {}; template <class T> value(T const& x) : base(x) {} // no move; I'm in C++03-land value& operator=(value const& x) { base::operator=(x); return *this; } } }; I don't know if I've missed some things that should be in that "value" class. I know that a recursive variant, in principle, requires a pointer indirection somewhere, so I was wondering if, had I wrapped object and array in recursive_wrapper as below, I would have been adding an unnecessary inefficiency. typedef variant< null, std::string, double, reference_wrapper<object>, reference_wrapper<array>, bool > value_base; I also wondered whether that would give me different results from typedef std::map<std::string, value> object; typedef std::vector<value> array; typedef variant< null, std::string, double, std::map<std::string, reference_wrapper<value> >, std::vector<reference_wrapper<value> >, bool > value_base; and which one was better. Does anyone know? I think that should be in the docs. Using recursive_variant_ works out quite nicely, except that it doesn't allow me to separately declare "object" and "array" and re-use them in the definition of "value": typedef boost::make_recursive_variant< null , std::string , double , std::map<std::string, boost::recursive_variant_> , std::vector<boost::recursive_variant_> , bool >::type value; I also wonder if I'm getting an unnecessary inefficiency in that case. Lastly, what flexibility am I sacrificing by using this approach? -- Dave Abrahams BoostPro Computing Software Development Training http://www.boostpro.com Clang/LLVM/EDG Compilers C++ Boost

9 28

[1.52.0] Release candidates available
by Marshall Clow 03 Nov '12

03 Nov '12

Release candidate files for 1.52.0 are available at http://boost.cowic.de/rc/ As always, the release managers would appreciate it if you download the candidate of your choice and give building it a try. Please report both success and failure, and anything else that is noteworthy. This helps ensure the candidates build OK before we push them out to SourceForge. Thanks, -- Marshall

5 5

New Stepanov lecture videos released by A9
by Mat Marcus 02 Nov '12

02 Nov '12

http://www.youtube.com/user/A9Videos/videos?flow=grid&view=1

1 0

[string_algo] Documentation Complaint
by Dave Abrahams 02 Nov '12

02 Nov '12

Wow, I found this documentation hard to use! I wanted to translate various 1-character substrings into new strings, e.g. translate the TAB character ('\t') to its textual escaped representation "\\t", and I went looking for an algorithm to do it. After 5 minutes of searching, I *think* the algorithm isn't there, but I'm still not sure. I nearly went blind (well, not really, but it felt that way) looking at http://www.boost.org/doc/libs/1_51_0/doc/html/string_algo/reference.html#he… because there's no vertical whitespace. More importantly, there's *no description of what any of these algorithms actually do*! ... calming down ... Heh, very terse descriptions are in the "Quick Reference": http://www.boost.org/doc/libs/1_51_0/doc/html/string_algo/quickref.html These might be good enough for me, but I always figure I'm going to get complete detail from the non-quick reference, and this one is just a dump of all the declarations, so I had to go around in a big circle and begin writing this documentation complaint before I found it. Can this situation be improved? -- Dave Abrahams BoostPro Computing Software Development Training http://www.boostpro.com Clang/LLVM/EDG Compilers C++ Boost

2 2

[Variant] Documentation Questions/Notes
by Dave Abrahams 02 Nov '12

02 Nov '12

- What does this mean? Full value semantics, including adherence to standard overload resolution rules for conversion operations. Seems to me that it's impossible *not* to adhere to any standard rules. Is the part after the comma vacuous? - The "temporary heap backup" technique seems to have a hole: 1. Copy-construct the content of the left-hand side to the heap; call the pointer to this data backup. 2. Destroy the content of the left-hand side. 3. Copy-construct the content of the right-hand side in the (now-empty) storage of the left-hand side. 4. In the event of failure, copy backup to the left-hand side storage. 5. In the event of success, deallocate the data pointed to by backup. What happens in the event of a failure in step 4? - I note the section on motivation doesn't mention the new capabilities of C++11 unions. Now some of the constructs are possible... *if* you do all the bookeeping yourself. - I note that the implementation has at least some support for move semantics and yet the docs require all elements to be "bounded types", which in turn are required to be CopyConstructible. Is that accurate, or outdated? - "completeness at the point of template instantiation" is a rather odd thing to put in a concept. I suggest that that should be just part of the requirements on the variant template rather than on BoundedType. - Do the semantics for are_strict_equals at http://www.boost.org/doc/libs/1_51_0/doc/html/variant/tutorial.html differ from those of the built-in equality operator? - it might be worth making the point that recursive variants offer the ability to define complex linked data structures *as value types* in a type- and memory-safe manner. I.e. no explicit handling of pointers; copy construction and assignment "just work," etc. -- Dave Abrahams BoostPro Computing Software Development Training http://www.boostpro.com Clang/LLVM/EDG Compilers C++ Boost

3 5

[optional] Doc Nit
by Dave Abrahams 01 Nov '12

01 Nov '12

> A typical approach is to consider the existence of a > valid return value as a postcondition, so that if the > function cannot compute the value to return, it has > either undefined behavior (and can use assert in a > debug build) or uses a runtime check and throws an > exception if the postcondition is violated. This is a > reasonable choice for example, for function (A), This is possibly technically correct, but confusing. Undefined behavior results from precondition violations, not postcondition violations. I'd suggest: One approach is to make a non-negative argument a precondition, so when violated the function has undefined behavior (and can use assert in a debug build). Alternatively, one can use a runtime check and specify that an exception is thrown if the postcondition cannot be satisfied. These are a reasonable choice for example, for function (A), I'm not sure the first sentence is quite right for your needs, but I'm out of time to improve it further. -- Dave Abrahams BoostPro Computing Software Development Training http://www.boostpro.com Clang/LLVM/EDG Compilers C++ Boost

2 1

Re: [boost] make_shared_array and allocate_shared_array
by Glen Fernandes 01 Nov '12

01 Nov '12

On Thu Nov 1 2012 at 1:48 PM, Olaf van der Spek <ml(a)vdspek.org> wrote: > Does Glen's make_shared_array have variants for both initialized and uninitialized allocations (for builtin types)? Hi Olaf, I just updated the code to only have initialization for non POD types: https://github.com/glenfe/glenfern/commit/05ea1f429bddfe7f07e4bb392db248492… Glen

1 0

Review: Code Review: allocate_shared_array and make_shared_array
by Glen Fernandes 01 Nov '12

01 Nov '12

A big thank you to Peter Dimov who has been kind enough to review my code. The open question we both have is whether these functions should continue to return shared_ptr<T> or be changed to return shared_array<T> after some modification to shared_array (both to support construction from (or conversion to) a shared_ptr and to have things like a no-throw constructor). Updated code: https://github.com/glenfe/glenfern/tree/master/boost Original blog post: http://glenfernandes.wordpress.com/ Some context from our discussion: Peter Dimov wrote: > Providing two separate sets of functions doesn't appeal to me much. > make_shared_array should return whatever we decide they should return. You > are right about shared_array's default constructor though, and maybe we can > use this opportunity to fix it (and add move support), and perhaps provide a > way for people to get a shared_ptr from a shared_array, if they have to work > with other people who only use that in their APIs. :-) > > Let's see what the Boost list will say. > > Glen Fernandes wrote: > > 1. I keep the functions returning shared_ptr but rename them to > > allocate_shared_sequence and make_shared_sequence. I think they are still > > useful for people who would want to avoid shared_array in their APIs for > > various reasons (e.g. its default constructor can throw). > >

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