September 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

9 16

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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[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.

7 8

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

3 6

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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[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/

6 17

[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

[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

[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

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

[#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

[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

[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

[contract] toward N3351 concepts
by Lorenzo Caminiti 13 Oct '12

13 Oct '12

Hello all, I'm reading N3351: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2012/n3351.pdf It's a bottom-up approach to define concepts starting from what's needed by STL algorithms. So far so good--I like it probably more than C++0x concept proposals--N331 is simpler :) However, N3351 STL design is not fully compatible with the current STL specifications--maybe N3351 is better, more mathematically sound? In N3351, concepts are boolean constants: ``We can define concepts as simple (constant) Boolean expressions. This is useful when building constraints predicated on non-syntactic and non-semantics properties of types.`` So I can implement concepts in C++11 as boolean meta-functions using expression SFINAE to check the requirements and enable_if to disable generic algorithms when the instantiated types don't model the concepts (i.e., the concept's boolean meta-function is false). For example, that's the case for the bool{a== b} and bool{a!=b} expressions of the EqualityComparable concept below. However, N3351 says that axioms should not be checked by the compiler... ``Axioms express the semantics of a concept’s required syntax; they are assumed to be true and must not be checked by the compiler beyond conformance to the C++ syntax. Any additional checking is beyond the scope of the compiler’s translation requirements. The compiler must not generate code that evaluates axioms as preconditions, either. This could lead to program errors if the evaluated assertions have side effects. For example, asserting that distance(first, last) > 1 when the type of those iterators is istream_iterator will consume the first element of the range, causing the assertion to pass, but the algorithm to have undefined behavior.'' So what am I supposed to do with axioms? Do nothing? Axioms are just "comments" that document the semantic? For example: `` concept EqualityComparable<typename T> = requires (T a, T b, T c) { bool { a == b }; bool { a != b }; axiom { a == b <=> eq(a, b); } // true equality axiom { a == a; // reflexive a == b => b == a; // symmetric a == b && b == c => a == c; // transitive } axiom { a != b <=> !(a == b); } // complement }; So, EqualityComparable<T> is true if T 1. has == and != with result types that can be converted to bool 2. == compares for true equality 3. == is reflexive, symmetric, and transitive 4. != is the complement of == However, the compiler can only check the first of these conditions. The rest must be verified through other means (i.e. manually). '' Thanks, --Lorenzo

16 82

[preprocessor] Variadics suggestion
by Kitten, Nicholas 11 Oct '12

11 Oct '12

Hi Folks, First of all, I'd like to say "thank you" to Edward Diener and Paul Mensonides for incorporating variadics support into Boost.Preprocessor, which has been on my wishlist for a long time. In fact, I wanted it badly enough that I've been using my own slightly modified version of the library assuming variadics for a while now, and I was interested to see what a cross-platform version would look like (mine was only tested on MSVC). I think the chosen approach of converting variadics to non-variadics is probably superior to the breaking algorithm changes I made in my own version, and I would humbly suggest a few more additions in the same spirit. The reason I chose to use variadics in the first place was to simplify the user interface for the common case of manipulating what I'll call a "variadic sequence," (a series of concatenated tuples), which I wanted to look similar to the following: #define FILTER_PARAMETERS (A, int, 3)\ (B, float, 2.0f)\ (C, const char*, "Howdy!") Of course, without variadics you need either a set of macros for each tuple size, or else double parenthesis around each tuple, which becomes even more burdensome when users are also required to parenthesize inner arguments, leading to gems like this one: #define FILTER_PARAMETERS ((A, (TypeConverter<double, float>), (TypeConverter<double,float>())) My solution admitting the preferred format was to replace most private SEQ_*(X) macros with SEQ_*(...), which also required modifying SEQ_ELEM() and SEQ_HEAD() to return (X) instead of X. However, it occurs to me now that a conversion function to go from variadic to regular sequences would've been easier to implement and backwards compatible; see the attached file, which I've tested in basic cases on MSVC 10 and gcc-4.3.4. The usage would be: #define SEQ (a,b,c)(1,2,3,4) BOOST_PP_VARIADIC_SEQ_TO_SEQ( SEQ ) // expands to ((a,b,c))((1,2,3,4)) I'm submitting this because I couldn't find a way to use some combination of TUPLE/VARIADICS and SEQ transformations to do the same thing succinctly, but if I'm just missing something, please let me know. Next, I would suggest having a documented IS_EMPTY(...) function for detecting an empty variadic list. Since is_empty.hpp already exists for single arguments (though undocumented), I would guess the variadic version would look quite similar. My own (MSVC) version is attached. Finally, I would suggest using the preceding IS_EMPTY(...) function to allow VARIADIC_SIZE(...) to return 0, i.e. something along the lines of: # define BOOST_PP_VARIADIC_SIZE(...) BOOST_PP_IIF( BOOST_PP_IS_EMPTY(__VA_ARGS__), 0, BOOST_PP_VARIADIC_SIZE_I( __VA_ARGS__ ) ) where BOOST_PP_VARIADIC_SIZE_I is the current definition of BOOST_PP_VARIADIC_SIZE. Thanks, -Nick Kitten Software Engineer Center for Video Understanding Excellence ObjectVideo, Inc.

9 29

[build] Boost Build v2 documentation refer to "bjam"
by Klaim - Joël Lamotte 11 Oct '12

11 Oct '12

Hi, http://www.boost.org/boost-build2/doc/html/bbv2/overview/invocation.html I suppose this doc have not been updated in a long time? It still use "bjam" instead of "b2". Joel Lamotte

3 3

[config] explicit call of operator templates / msvc bug workaround
by Stefan Strasser 10 Oct '12

10 Oct '12

Hi, is there already a macro in Boost.Config that allows you to insert the "template" keyword in the following code for those compilers that require it? struct functor{ template<class T> void operator()(); }; template<class F> void g(F f){ f.template operator()<int>(); //(1) works with GCC and comeau f.operator()<int>(); //(2) works with MSVC } this apparently only applies to operator calls. MSVC accepts both (1) and (2) for regular functions. (instantiating the operator template with an object of type T as argument, like mpl::for_each does, is not an option. I can't construct T.) thanks, Stefan

6 10

[graph][heap][coroutine] interruptable dijkstra shortest path function
by Alex Hagen-Zanker 05 Oct '12

05 Oct '12

[apologies for double posting, send it to wrong list before] Hi, A few months ago I posted here to gauge interest for an interruptable and resumable version of the dijkstra_shortest_path algorithm. The initial response was positive, but Jeremiah considered the proposed solution lacking compared to an algorithm object model that inverts the control over the algorithm, Additional to my original solution, I now have two implementations of the algorithm object model. 1. Visitor based interruption. This is my original approach. It separates the algorithm into an init and main function. The main function asks the visitor if it should be halted afer each iteration. After halting, the main function can be used to resume the calculation. auto dijkstra = make_dijkstra_object(graph, named_parameters); dijkstra.init_from_sources(sources); dijkstra.expand( interruptor); dijkstra.expand( other_interruptor); auto distance_map = dijkstra.get<vertex_distance_t>(); auto color_map = dijkstra.get<vertex_color_t>(); 2. Algorithm object implementation. This was suggested by Jeremiah. The algorithm object iterates from control point to control point in the algorithm. Giving at each stop access to the intermediate results of the algorithm. The two implementations are: a) Using the [Coroutine] library that is currently under review to step in and out of the function. b) Fragmenting the function into many subfunctions that are chained together and the other works by fragmenting the original algorithm into a number of small interlinked functions starting at one control point and returning at the next. The interface of a and b is exactly the same and it works like this: auto dijkstra = make_dijkstra_object(graph, sources, named_parameters); while(dijkstra.next() ) { control_point cp = dijkstra.get_control_point(); vertex u = dijkstra.get_u(); auto distance_map = dijkstra.get<vertex_distance_t>(); if(cp == cp_finish_vertex && get(distance_map, u) > 42) { cout << "far enough" << endl; break; } } auto distance_map = dijkstra.get<vertex_distance_t>(); The algorithm object offers most flexibility for interweaving multiple searches. The visitor based solution on the other hand is more efficient. The latter has no loss in performance compared to the existing dijkstra functions. The coroutine algorithm object was extremely easy to implement but it is not very efficient. Does anybody have a suggestion how that can improve? Besides these interruptable and resumable shortest path searches, there are a few more advantages to the implementation. a. All dijkstra parameters are bundled in a light-weight dijkstra_state object that is returned by algorithms, giving direct access to all results of the algorithm, for instance: auto dijkstra_state = dijkstra_shortest_paths(graph, sources, no_named_parameters() ); auto distance_map = dijkstra_state.get<vertex_distance_t>(); b. Named parameters (old style) are also used for the priority queue and the color map c. Boost.Heap mutable queues can be used with Boost.Graph via the named parameter interface. It doesn't help performance now, but may be a good base for experimentation. d. Separation of the dijkstra shortest path algorithm in init and main function makes it easier to provide custom initialization. For instance: multiple sources or only re-initializing changed vertices Can anybody use this? The latest version is here: http://people.pwf.cam.ac.uk/ahh34/dijkstra.zip Kind regards, Alex p.s. below are timings for a large graph: bimba_6M.obj... 2090 ms. Boost Graph Library 2121 ms. With interruption visitor 5601 ms. With Coroutine(*) 2621 ms. With fragmented functions (*) 2840 ms. With Boost.Heap (*) halting at all control points of the dijkstra visitor

8 21

Boost.Generic, C++0x Concepts, and C++1y Concepts
by Matt Calabrese 05 Oct '12

05 Oct '12

Hey everyone, It's been a while since I've made an appearance on this list, but I was contacted regarding the recent discussion of concepts here and Lorenzo's taking the reins of a concept library, and decided to poke my head in. First, I apologize to the community for not getting Boost.Generic on the sandbox earlier (if you are unfamiliar with Boost.Generic, see my 2011 BoostCon talk http://blip.tv/boostcon/boost-generic-concepts-without-concepts-5262126 and/or the corresponding slides https://github.com/boostcon/2011_presentations/raw/master/thu/Boost.Generic… ). I've gotten numerous emails about it since 2011 and I decided to commit the current state of Boost.Generic to the sandbox today. It is still based on the "old" concepts of C++0x with pseudo-signatures. You can find it in the "generic" subdirectory of the sandbox. That said, I'm not sure anyone even cares about Boost.Generic anymore given that the standard seems to be diverging from how it originally was approaching concepts, but here it is anyway. Similarly, I'm not sure there is any interest from people for me to continue developing Boost.Generic, so I guess this is a check for interest again. And, very briefly, without getting too political here (not that my opinion has any bearing) but I personally do not agree with some of the recent design changes for what may turn out to be C++1y concepts -- specifically I think pseudo-signatures were better overall and the C++0x form of associated types was much more useful than what is currently described, especially concerning associated type deduction, which no longer appears to be possible. But I don't think this discussion is suitable for the Boost mailing list and I don't want to ruffle too many feathers beyond that, so I'll take that elsewhere. For this reason, though, I [currently] do not have a desire to support that form of concepts in my library, though I do plan to resume work on Boost.Generic. A recap of what's gone on since my Boostcon talk, for anyone who even remembers it -- I haven't been actively developing Boost.Generic for over a year as I have been busy with other things, but coincidentally in the past couple of weeks I've gone back to it and decided to update some things due to a trick I realized I could use to get full compatibility with the C++0x working paper for explicit concept map templates (N2914's 14.10.3.2 paragraph 3 highlights why it's non-trivial, see http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2914.pdf) Since then, I've had renewed interest in the project and have updated various facilities. Stuff that changed since my presentation back in 2011 -- it now supports variadic concepts using the syntax ,,, (see line 28 of boost/generic/std_concept/concepts/predicate.hpp for a simple example). All 135 of the concepts from N2914 are now implemented, though not all are working, especially ones that are not auto and use refinement (I'm still in the process of making the concept map backend changes). All of the std_concepts/concepts tests should be working, and same with std_concept/support_concepts tests, with GCC and Clang only failing on FreeStoreAllocatable (in slightly different ways). I'm updating some of the implementation to use the new Boost.Preprocessor variadic macro support that didn't exist when I started development, and Boost.Generic now also is starting to use Edward Diener's variadic_macro_data_library that's in the sandbox. I've only recently test on GCC 4.7 and Clang 3.1, both with libstdc++ on Windows. I don't think any other compilers will be able to handle it because of the amount of C++11 features currently in use... Visual C++ in particular will likely have no chance of compiling ANY of it, even if you use the fully preprocessed form of the library that I provided on the sandbox. Specifically, I currently require the updated C++11 SFINAE support, variadic templates, and template aliases, among other features which I don't believe Visual C++ yet supports. If you want to see how to use the library, for now you'll have to watch the talk, look at the slides, and/or go into generic/test/libs/generic/test/std_concept and examine the tests that are there (the latter will probably be the most enlightening in terms of using the predefined concepts). As for the tests, the ones you should look at if you want to understand how to use the predefined concepts are in the test directory's std_concept/concepts and std_concept/support_concepts subdirectories. If you want to see the syntax for creating your own concepts, the ones in std_concept/concepts are the best choice to look at, as they are simple and most do not require compiler intrinsics, unlike the support_concepts which rely on C++11 type_traits and the C++0x std::True concept. I also recently integrated Boost.Wave support to easily generate preprocessed versions of all of the concepts in the library. You can use the preprocessed headers, including Dave's suggested #line support, without having to run Boost.Wave yourself. To do this you just define a couple of macros when you build the tests. This decreases build times by over 50% on both Clang and GCC -- the tests for me in Clang go from over 7 minutes to just over 3 minutes if I use the preprocessed headers. To activate this support you need the two defines in the following format (easiest to just define them via the command-line) // NOTE: Do not use quotes around the path -- also realize that the path ends in the middle of the word generic, This is necessary. #define BOOST_GENERIC_PREPROCESSED_ROOT put_your_COMPLETE_path_to_boost_sandbox_here/generic/include/boost/gen // Also #define BOOST_GENERIC_USE_PREPROCESSED_HEADERS This will use completely preprocessed concepts, with errors properly pointing to the non-preprocessed headers, and effectively gets rid of all of the "from macro invocation" notes you'd see in clang and gcc 4.8 whenever you hit one of the Boost.Generic generated static_asserts in the non-preprocessed form. It is recommended that you use the preprocessed form unless you are making changes to the library-provided concepts, since compile-times are greatly reduced by using them and error messages are improved. Anyway, as I said, I do not personally like the direction that concepts seem to be going and so I do not currently have much of an interest in implementing what is currently proposed, however, buried somewhere in the source of Boost.Generic I believe is an early implementation of the library that was more similar to how concepts are specified in N3351, though I stopped maintaining it a long time ago -- it allowed for the specification of givens and arbitrary expression matching similar to the current design, with a brief demonstration given in my 2011 Boostcon talk (slide 20: https://github.com/boostcon/2011_presentations/raw/master/thu/Boost.Generic…) It might be useful to revive this now that standard concepts may be going in that direction, but again, I do not think this is a good idea and was why I was convinced by others to switch development to pseudo-signatures to begin with. -- -Matt Calabrese

3 16

Who maintains boost MPI?
by Ralf Grosse-Kunstleve 04 Oct '12

04 Oct '12

Hi, we're looking for someone to merge a simple patch: https://svn.boost.org/trac/boost/ticket/6123 Ralf

4 4

[spirit] Symbols parser with overlapping symbols
by Andrey Semashev 01 Oct '12

01 Oct '12

Hi, I wonder how qi::symbols parser behaves when it contains partially overlapping symbols. For example: qi::symbols< char, int > syms; syms.add("a", 1); syms.add("aaa", 2); What will this parser return when "aaa" is passed as input? I couldn't find it in the docs.

2 1

[1.52.0] [request permission to merge to release] Changeset 80790
by Jeffrey Lee Hellrung, Jr. 30 Sep '12

30 Sep '12

As I was updating the Release Notes for 1.52.0, I thought about a recently introduced restriction on function_input_iterator (due to addressing ticket #5825 [1] in [2]) that could be relaxed. trunk changeset is here: https://svn.boost.org/trac/boost/changeset/80790 I think it's pretty benign but given that the release branch is closed tomorrow (Monday) and the beta rc is just a few days after that, I figured that whether and when this gets merged to release is up to the release managers. Please advise, - Jeff [1] https://svn.boost.org/trac/boost/ticket/5825 [2] https://svn.boost.org/trac/boost/changeset/80467

1 1

Inspection tool run
by Paul A. Bristow 30 Sep '12

30 Sep '12

I've been trying to get Boost.Math off the Sinners List on the Inspection Report at http://boost.cowic.de/rc/inspect-trunk.html#math. It last ran 25 July 12, so I can't see if I have succeeded yet. When can I expect it to run again? Paul --- Paul A. Bristow, Prizet Farmhouse, Kendal LA8 8AB UK +44 1539 561830 07714330204 pbristow(a)hetp.u-net.com

8 12

[website] Latest version of page links
by Daniel James 30 Sep '12

30 Sep '12

Hello all, I finally got round to finishing off the links from old documentation to the latest version. It's a little hacked in so the markup isn't wonderful, and it only works for libraries whose documentation is altered by the site's php scripts. That's usually the documentation with no frames and the green header (some libraries put the green header in themselves, it won't work for them). At the moment it's just on the beta site, for example: http://beta.boost.org/doc/libs/1_49_0/libs/phoenix/doc/html/index.html Not all pages have a page in the same location in the most recent version, so for some pages you will just get a link to the latest documentation list: http://beta.boost.org/doc/libs/1_41_0/doc/html/boost/units/si/constants/cod… This will go live soonish. I might tweak it a little first, maybe change the wording on the notices, but it's pretty much done for now. Please try it out with your favourite documentation to check I haven't made too much of a mess. thanks, Daniel

2 2

Review Wizard Status Report for September 2012
by Ronald Garcia 29 Sep '12

29 Sep '12

============================================== Review Wizard Status Report for September 2012 ============================================== News ==== 1. Boost 1.51.0 Released. New Libraries: 1) Context 2. Multiprecision Accepted 3. Type Erasure Accepted 4. Contract Reviewed 5. Coroutine Reviewed 6. ODEInt Reviewed 7. Contract Accepted 8. Polygon Extensions integrated into Polygon 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) ``(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 Libraries under development =========================== See http://svn.boost.org/trac/boost/wiki/LibrariesUnderConstruction for a current listing of libraries under development.

3 5

[Review] ODEInt review starts today, September 19, ends September 28
by Steven Watanabe 28 Sep '12

28 Sep '12

AMDG The review of Karsten Ahnert and Mario Mulansky's ODEInt library starts today September 19th and will end on September 28. -------------------------------------- About the library: odeint provides routines for numerically solving Ordinary Differential Equations, a task heavily required when approaching scientific problems numerically. In odeint we have implemented the most common algorithms in a modern, generic way which provides several advantages over existing implementations. The main focus of odeint is to separate algorithms from the underlying basic computation unit. This allows for example to easily use the power of modern GPUs via CUDA or OpenCL to speed up computational heavy simulations. Features: - provides most of the standard algorithms, including step size control, dense ouput and extrapolation routines - symplectic routines for Hamiltonian systems - implicit routines based on boost::ublas (MTL4 in progress) - high level integrate functions - interchangeable computation backend with existing bindings to CUDA and OpenCL - native support of ODEs defined for complex values - support of Boost.Units in most of the algorithms - support of arbitrary precision types You can download the library and view the documentation here: zip: http://github.com/headmyshoulder/odeint-v2/zipball/master github: http://headmyshoulder.github.com/odeint-v2/ docs: http://headmyshoulder.github.com/odeint-v2/doc/index.html -------------------------------------- Please always state in your review, whether you think the library should be accepted as a Boost library! Additionally please consider giving feedback on the following general topics: - What is your evaluation of the design? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - What is your evaluation of the potential usefulness of the library? - Did you try to use the library? With what compiler? Did you have any problems? - How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? - Are you knowledgeable about the problem domain? In Christ, Steven Watanabe

6 8

Contributing a thread pool class
by BOLTON Gawain 28 Sep '12

28 Sep '12

Hello, It seems that boost's "thread" library does not have a thread pool class. It does have a thread_group class but this class is has the following limitations: 1. It does not limit the number of threads created. 2. Threads added are not managed and raw pointers are used exposing the developer to memory leaks. 3. The API deals with threads and not "tasks" to be executed by a thread. As such I have developed a thread pool class which allows for: · A maximum number of "worker" threads to configured. · Arbitrary "tasks" to be submitted by any thread and executed by one of the worker threads. o Worker threads are created as and when needed. · Worker threads can terminate after being idle a configurable amount of time. o They will be re-created if needed afterwards. The amount of code is quite small (< 500 lines including blank lines, API usage document in the header file and comments) and just uses standard C++ and boost thread functionality. My question is, would the boost community be interested in such a contribution to the thread library? I apologize in advance if this is the Nth time such a contribution has been proposed and rejected. I have developed this while working for my employer (a French bank called Société Générale). I have my manager's support and am in the process of obtaining agreement from my employer to get permission to submit the thread pool class developed. Cheers, Gawain Bolton Domino Development ITEC/CTT/GEF/TED 17 cours Valmy 92 800 Puteaux France Telephone : +33 1 42 13 52 43 ************************************************************************* This message and any attachments (the "message") are confidential, intended solely for the addressee(s), and may contain legally privileged information. Any unauthorised use or dissemination is prohibited. E-mails are susceptible to alteration. Neither SOCIETE GENERALE nor any of its subsidiaries or affiliates shall be liable for the message if altered, changed or falsified. ************ Ce message et toutes les pieces jointes (ci-apres le "message") sont confidentiels et susceptibles de contenir des informations couvertes par le secret professionnel. Ce message est etabli a l'intention exclusive de ses destinataires. Toute utilisation ou diffusion non autorisee est interdite. Tout message electronique est susceptible d'alteration. La SOCIETE GENERALE et ses filiales declinent toute responsabilite au titre de ce message s'il a ete altere, deforme ou falsifie. *************************************************************************

3 2

Release branch closing for new features
by Marshall Clow 27 Sep '12

27 Sep '12

[ resending because it doesn't seem to have gone through ] So, we missed announcing this on Monday, so we're pushing back the deadline until Friday. On (tomorrow) Friday, Sep 29th, the release branch will close for new features, and be open only for bug fixes and doc fixes. On Tuesday, October 2nd, the release branch will close except by permission from the release managers. This is in preparation for the first 1.52.0 beta, scheduled for Monday, Oct 8th. -- The release managers

1 0

[reminder] [Review] ODEInt review ends tomorrow September 28
by Steven Watanabe 27 Sep '12

27 Sep '12

AMDG The review of Karsten Ahnert and Mario Mulansky's ODEInt library will end tomorrow. Only a few reviews have been submitted so far. If you plan to submit a review, please let me know. If anyone needs more time, we can see about extending the review period. -------------------------------------- About the library: odeint provides routines for numerically solving Ordinary Differential Equations, a task heavily required when approaching scientific problems numerically. In odeint we have implemented the most common algorithms in a modern, generic way which provides several advantages over existing implementations. The main focus of odeint is to separate algorithms from the underlying basic computation unit. This allows for example to easily use the power of modern GPUs via CUDA or OpenCL to speed up computational heavy simulations. Features: - provides most of the standard algorithms, including step size control, dense ouput and extrapolation routines - symplectic routines for Hamiltonian systems - implicit routines based on boost::ublas (MTL4 in progress) - high level integrate functions - interchangeable computation backend with existing bindings to CUDA and OpenCL - native support of ODEs defined for complex values - support of Boost.Units in most of the algorithms - support of arbitrary precision types You can download the library and view the documentation here: zip: http://github.com/headmyshoulder/odeint-v2/zipball/master github: http://headmyshoulder.github.com/odeint-v2/ docs: http://headmyshoulder.github.com/odeint-v2/doc/index.html -------------------------------------- Please always state in your review, whether you think the library should be accepted as a Boost library! Additionally please consider giving feedback on the following general topics: - What is your evaluation of the design? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - What is your evaluation of the potential usefulness of the library? - Did you try to use the library? With what compiler? Did you have any problems? - How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? - Are you knowledgeable about the problem domain? In Christ, Steven Watanabe

1 0

heap corruption on windows due to windows_file_codecvt
by Pedro Larroy 27 Sep '12

27 Sep '12

Hi When using debug mode in windows with boost_filesystem there's "Debug Assertion Failed!" in _CtrIsValidHeapPointer When operator new is redefined it causes windows_file_codecvt not to be released with the matching release that it allocated it. We reported this to Microsoft as seems it's a bug in their STL. But so far, I tried with VS2012 and the bug seems not fixed... There's a workraround in boost that we are using for the moment: This has to be changed in path.cpp to fix it: - std::locale loc(global_loc, new windows_file_codecvt); + std::locale loc(global_loc, _NEW_CRT windows_file_codecvt); Should this fix be applied in boost until is fixed on Microsoft's side? This is a very nasty issue that will happen only with a redefined operator new. (For example we are using new with the sacalable allocator of tbb). Regards. Pedro.

1 0

[context] boost::ctx::?
by Dave Abrahams 27 Sep '12

27 Sep '12

ctx seems like a needlessly short abbreviation. Wouldn't it be better and more consistent with the rest of Boost to ask users to write using namespace ctx = boost::context; if they want something short? -- Dave Abrahams BoostPro Computing Software Development Training http://www.boostpro.com Clang/LLVM/EDG Compilers C++ Boost

9 13

[shared_ptr][thread] spinlock initialization
by Yi Ding 27 Sep '12

27 Sep '12

I started using the spinlock in boost/smart_ptr/detail/spinlock.hpp and discovered that it needs to be manually initialized, even for the spinlock_sync version, which became a nasty bug when it manifested itself. This seems a bit out of sync with the rest of the mutexes in boost::thread. Now, I'm guessing that the fact that the spinlock is in boost::detail means that it's not really for outside consumption (newbie boost user here), but is there something in the works that will be? In the meantime, would it be possible to automatically initialize the spinlock (trivial in the case of spinlock_sync) or are there architectural issues with that? Otherwise, could we add a comment that says "in order to use these spinlocks you must initialize with BOOST_DETAIL_SPINLOCK_INIT" or "move along, these aren't the spinlocks you're looking for."

3 2

Problem using dijkstra_shortest_paths with Boost 1.51
by John Wiegley 27 Sep '12

27 Sep '12

Hello, I tried building my Ledger project today with Boost 1.51 and clang --std=c++11, and received the following error: --8<---------------cut here---------------start------------->8--- /usr/local/include/boost-1_51/boost/mpl/eval_if.hpp:38:26: error: no type named 'type' in 'boost::no_property' typedef typename f_::type type; ~~~~~~~~~~~~~^~~~ [...] /Users/johnw/Projects/ledger/src/history.cc:455:3: note: in instantiation of function template specialization 'boost::dijkstra_shortest_paths<boost::filtered_graph<boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS, boost::property<boost::vertex_name_t, const ledger::commodity_t *, boost::property<boost::vertex_index_t, unsigned long, boost::no_property> >, boost::property<boost::edge_weight_t, long, boost::property<boost::edge_price_ratio_t, std::__1::map<boost::posix_time::ptime, ledger::amount_t, std::__1::less<boost::posix_time::ptime>, std::__1::allocator<std::__1::pair<const boost::posix_time::ptime, ledger::amount_t> > >, boost::property<boost::edge_price_point_t, ledger::price_point_t, boost::no_property> > >, boost::property<boost::graph_name_t, std::__1::basic_string<char>, boost::no_property>, boost::listS>, ledger::recent_edge_weight<boost::adj_list_edge_property_map<boost::undirected_tag, long, long &, unsigned long, boost::property<boost::edge_weight_t, long, boost::property<boost::edge_price_ratio_t, std::__1::map<boost::posix_time::ptime, ledger::amount_t, std::__1::less<boost::posix_time::ptime>, std::__1::allocator<std::__1::pair<const boost::posix_time::ptime, ledger::amount_t> > >, boost::property<boost::edge_price_point_t, ledger::price_point_t, boost::no_property> > >, boost::edge_weight_t>, boost::adj_list_edge_property_map<boost::undirected_tag, ledger::price_point_t, ledger::price_point_t &, unsigned long, boost::property<boost::edge_weight_t, long, boost::property<boost::edge_price_ratio_t, std::__1::map<boost::posix_time::ptime, ledger::amount_t, std::__1::less<boost::posix_time::ptime>, std::__1::allocator<std::__1::pair<const boost::posix_time::ptime, ledger::amount_t> > >, boost::property<boost::edge_price_point_t, ledger::price_point_t, boost::no_property> > >, boost::edge_price_point_t>, boost::adj_list_edge_property_map<boost::undirected_tag, std::__1::map<boost::posix_time::ptime, ledger::amount_t, std::__1::less<boost::posix_time::ptime>, std::__1::allocator<std::__1::pair<const boost::posix_time::ptime, ledger::amount_t> > >, std::__1::map<boost::posix_time::ptime, ledger::amount_t, std::__1::less<boost::posix_time::ptime>, std::__1::allocator<std::__1::pair<const boost::posix_time::ptime, ledger::amount_t> > > &, unsigned long, boost::property<boost::edge_weight_t, long, boost::property<boost::edge_price_ratio_t, std::__1::map<boost::posix_time::ptime, ledger::amount_t, std::__1::less<boost::posix_time::ptime>, std::__1::allocator<std::__1::pair<const boost::posix_time::ptime, ledger::amount_t> > >, boost::property<boost::edge_price_point_t, ledger::price_point_t, boost::no_property> > >, boost::edge_price_ratio_t> >, boost::keep_all>, f_max<long>, boost::distance_combine_t, boost::bgl_named_params<boost::iterator_property_map<long *, boost::vec_adj_list_vertex_id_map<boost::property<boost::vertex_name_t, const ledger::commodity_t *, boost::property<boost::vertex_index_t, unsigned long, boost::no_property> >, unsigned long>, long, long &>, boost::vertex_distance_t, boost::bgl_named_params<boost::iterator_property_map<unsigned long *, boost::vec_adj_list_vertex_id_map<boost::property<boost::vertex_name_t, const ledger::commodity_t *, boost::property<boost::vertex_index_t, unsigned long, boost::no_property> >, unsigned long>, unsigned long, unsigned long &>, boost::vertex_predecessor_t, boost::no_property> > >' requested here dijkstra_shortest_paths(fg, /* start= */ vs, ^ --8<---------------cut here---------------end--------------->8--- My graph type is: typedef adjacency_list <vecS, // Store all edges in a vector vecS, // Store all vertices in a vector undirectedS, // Relations are both ways // All vertices are commodities property<vertex_name_t, const commodity_t *, property<vertex_index_t, std::size_t> >, // All edges are weights computed as the absolute difference between // the reference time of a search and a known price point. A // filtered_graph is used to select the recent price point to the // reference time before performing the search. property<edge_weight_t, long, property<edge_price_ratio_t, price_map_t, property<edge_price_point_t, price_point_t> > >, // Graph itself has a std::string name property<graph_name_t, std::string> > Graph; The full source is located here: https://github.com/jwiegley/ledger/blob/next/src/history.cc What has changed in Boost.Graph since 1.50? The same code builds fine with all the same compiler options using that version. Thanks, -- John Wiegley BoostPro Computing Software Development Training http://www.boostpro.com Clang/LLVM/EDG Compilers C++ Boost

2 4

[odeint] Documentation comments
by John Bytheway 27 Sep '12

27 Sep '12

This is not a review, just a few things I've caught while reading the odeint docs. Mostly cosmetic issues, but a couple of deeper questions. * http://headmyshoulder.github.com/odeint-v2/doc/boost_numeric_odeint/getting… - "They also occur if partial differential equations (PDEs) are discretized in one coordinate."; wouldn't you have to discretize in all but one coordinate? * http://headmyshoulder.github.com/odeint-v2/doc/boost_numeric_odeint/getting… - I see no mention of any headers except the global one boost/numeric/odeint.hpp. Is it useful or possible to include only parts of the library? * http://headmyshoulder.github.com/odeint-v2/doc/boost_numeric_odeint/getting… - "a simple function calculating f(x)'"; I think you mean either "f(x)" or "x'", not "f(x)'". * http://headmyshoulder.github.com/odeint-v2/doc/boost_numeric_odeint/tutoria… - There's one case here where you use "--" as an em dash. "on the example of explicit_error_rk54_ck -- a 5th order Runge-Kutta method". There are various other places throughout the docs which use just "-" for em dash. It would be best if you could use a proper em dash character, but in any case you should be consistent. * http://headmyshoulder.github.com/odeint-v2/doc/boost_numeric_odeint/tutoria… - "which lead to the whole new subject of Chaos Theory"; s/lead/led/ * http://headmyshoulder.github.com/odeint-v2/doc/boost_numeric_odeint/tutoria… - "the so called Rosenbrock method"; is "so called" necessary? * http://headmyshoulder.github.com/odeint-v2/doc/boost_numeric_odeint/tutoria… - "the first numerical experiment which has been implemented on a computer in 1953. It was studied at Los Alamos on one of the first computer (a MANIAC I) and it triggered a whole new tree of mathematical and physical science."; This is ambiguous (it could mean the first experiment amongst those in 1953). If you really mean it was the first computational numerics experiment then you should probably say something like "the first numerical experiment to be implemented on a computer. It was studied at Los Alamos in 1953 on one of the first computers (a MANIAC I) and triggered a whole new tree of mathematical and physical science." - "For example the unit test for Boost.Units take up to 4 GB of memory at compilation."; are you referring to the unit tests of Boost.Units, or a unit test of odeint that uses Boost.Units? Please clarify. - The matrix-as-state example has a bug: for( size_t j=0 ; j<x.size2() ; ++j ) dxdt( 0 , j ) = dxdt( 0 , x.size1() -1 ) = 0.0; should be for( size_t j=0 ; j<x.size2() ; ++j ) dxdt( 0 , j ) = dxdt( x.size1() -1, j ) = 0.0; This bug makes me think that you ought to provide a debug mode where every entry in dxdt is set to NaN before calling the system operator(), and then they are checked to be non-NaN afterwards. Of course, this would only work for types with a NaN value, but I think all your examples do have that (except maybe the multiprecision types). - "This is in principle all"; awkward phrasing, perhaps "In principle this is all" - I assume you know about the unfinished chunk of docs re PDEs and equations on networks. - "for full support the min( x , y ), max( x , y ), pow( y , y ) must be callable"; what are x and y? Is it significant that pow has both arguments equal but min and max don't? I hope the requirements on the numeric type are laid out more formally elsewhere; please link to that. - "We exemplary show this for a Hamiltonian system"; "exemplary" doesn't work here. You could use s/exemplary show/demonstrate/. * http://headmyshoulder.github.com/odeint-v2/doc/boost_numeric_odeint/tutoria… - "simply to small"; s/to/too/ * http://headmyshoulder.github.com/odeint-v2/doc/boost_numeric_odeint/odeint_… - "Implicit solvers do only work"; s/do // - "They safe a part of their history" s/safe/save/ - In the section on controlled steppers, the formulae are getting sufficiently complex that it might be worth trying to use TeX-generated pngs rather than straight HTML (as is done in Boost.Math, e.g. <http://www.boost.org/doc/libs/1_51_0/libs/math/doc/sf_and_dist/html/math_to…>) - I can't figure out what the three lines after table 1.6 are about. - The long line "boost::numeric::odeint::result_of::make_dense_output< r..." in Dense output steppers is too long for my screen; can you break it? - The resizing policy names are a bit clumsy; I think always_resize, initially_resize, and never_resize might be better. - "Typical use cases for this kind of resizer are self expanding lattices like shown in the tutorial"; can you link to the relevant example in the tutorial? - "So it might be suitable that the system function itself is a pair of functions, one for computing the deterministic and one for the stochastic part. The first element of the pair simply computes the deterministic part while the second the stochastic one."; this is rather redundant; how about "So it might be suitable that the system function is a pair of functions. The first element of the pair computes the deterministic part and the second the stochastic one." * http://headmyshoulder.github.com/odeint-v2/doc/boost_numeric_odeint/odeint_… - Personally I think the ranges are more useful than the iterators, so it would be nice if they were mentioned in the section title (e.g. "Iterators and Ranges") - "that is you write the above example in a shortified form"; "shortified" is not a word; perhaps "so you can write this example in a more succinct form". * http://headmyshoulder.github.com/odeint-v2/doc/boost_numeric_odeint/odeint_… - The note "odeint already includes all the code presented here, see gsl_wrapper.hpp, so gsl_vectors can be used straight out-of-box. The following description is just for educational purpose." is duplicated in the subsequent paragraph. - Using x/y for element-wise division in vector_space_algebra seems potentially contentious. Similarly for abs. Perhaps it would be better to provide a customization point in boost::numeric::odeint as you have done with vector_space_reduce, whose default implementations use / and abs as in the current scheme. That way people will not be required to implement potentially misleading operators for their types. - "vector_space_reduce_impl< state_type >::reduce( state , operator , init )"; you probably shouldn't use the keyword "operator" as an identifier here. * http://headmyshoulder.github.com/odeint-v2/doc/boost_numeric_odeint/odeint_… - "the state_type of the stepper must not necessarily be used to call the do_step method"; I'm not sure what this means; should it be "the state_type of the stepper need not necessarily be used to call the do_step method" * http://headmyshoulder.github.com/odeint-v2/doc/boost_numeric_odeint/concept… - Concepts are normally written without underscores, so SymplecticSystem rather than Symplectic_System. * http://headmyshoulder.github.com/odeint-v2/doc/boost_numeric_odeint/concept… - In various places you have ScaleSum/N/ with literal '/' characters, where I presume they were intended to be formatting to make 'N' italics. - Rather than having a dedicated array_algebra, could you not have range_algebra automatically switch to the more efficient implementation when it detects a suitable State type? I hope to get a chance to play with the library later and submit a proper review. For now, congratulations on an impressive library. John Bytheway

3 6

[test] Patches to improve test log detail for better thirdparty integration
by Jamie Allsop 26 Sep '12

26 Sep '12

In light of recent discussions regarding Boost.Test I've created 3 tickets in trac with patches against trunk that incrementally improve the ease with which Boost.Test can be integrated with thirdparty continuous integration tools, while at the same time improving the output offered. These are patches we've been using for some time locally, the recent discussions highlighted the importance of pushing patches like these to a wider audience. In summary the key changes are: * https://svn.boost.org/trac/boost/ticket/7410 * all test cases/suites have file and line information captured so that external tools can use the Boost.Log output to create links into the source tree, answering questions like, "What is this test case?". It is possible to simply follow the link and see. * https://svn.boost.org/trac/boost/ticket/7417 * update the Boost.Test log output to include summary status information when a test case or suite is completed. This includes the test status, assertions passed and total assertions. This allows live test status to be viewed and nicer tools to be built around this. For example each test can be shown starting, in progress and then complete with the resulting status in detail. I should note that Boost.Test reports currently output this additional test status but this is done only on completion of all tests and so cannot be used to show live progress. * this additional test status as part of the log can be easily captured using regular expressions if HRF is used and many IDEs will allow colourisation, autolinking and so on using similar approaches. * https://svn.boost.org/trac/boost/ticket/7397 * update Boost.Test to use the new Boost.Timer classes introduced in Boost 1.48. This can be suppressed through the use of a macro should the old timers be preferred. The new Boost.Timer provides much better timing information than the old Boost.Timer library. You should refer to the library itself for an explanation of why the previous timer library was deprecated: http://www.boost.org/doc/libs/1_51_0/libs/timer/doc/index.html These patches address what I believe to be important missing features of Boost.Test. We have been using these patches in our systems with Boost 1.49 and enjoy very nice CI integration with Trac Bitten and our Scons build tools. I would therefore encourage those that use Boost.Test and who are interested in these patches in general to take a look. The Boot.Timer patch is important as it also addresses compile issues. See the recent thread here: http://thread.gmane.org/gmane.comp.lib.boost.devel/234411 Gennadiy - assuming you find these acceptable they could be committed to trunk. I don't have commit privileges to do it myself and besides they need reviewed first. Also I would prefer a closer look was taken at the impact they might have on Boost.Test's tests. Finally I should also note that one reason for providing the BOOST_TEST_USE_DEPRECATED_TIMER macro was to circumvent the issue of the new Boost.Timer depending on Boost.System. I don't recall if Boost.System can used header-only? I certainly remember a lot of discussion about it. Jamie

2 2

[test] Support use of test tools and report generation in non-test programs - facilitating test/validation modes
by Jamie Allsop 26 Sep '12

26 Sep '12

An important use case that we have is the ability to run test scenarios on a production binary by specifying a 'test' mode. In test mode we essentially run through a series of different scenarios, asserting various conditions, comparing expected results and so on. In order to minimise the custom code we needed for this we decided to make use of Boost.Test. All the test tools are there, report generation and so on. In addition we have all the report analysis tools in place to interpret the output. The problem however, is that Boost.Test essentially requires a custom main() function. Either one of the ones provided by Boost.Test or one performing Boost.Test specific initialisation. In our production systems we have, like many, a fairly standard main() that ensures uniform behaviour across binaries and we do not want to pollute that with Boost.Test specific code. Notably we also do not want to pollute our command line parameters or configuration with 'global' Boost.Test arguments to control the test report output. Finally we want to control exactly when the tests are executed. I've created ticket #7419 to cover this use case and have also attached a small patch that facilitates the capabilities required to support it. https://svn.boost.org/trac/boost/ticket/7419 Essentially the patch does two things: * It allows boost::unit_test_framework::init() to be called more than once. The result is to reset the test status and master test suite so that new tests can be added and new reports generated through multiple calls. The CLA parsing is also reset. Recent changes to this code may make my call to clear() redundant. I'll let Gennadiy be the judge of that. * This first change then allows the framework setup and teardown to be encapsulated in a helper class (not provided in the patch but one could be). In our systems we use a helper class that exposes a simple API that allows the user to implement a method where test units can be added directly to the master test suite - see the ticket for an example. As I said the patch focuses solely on enabling the possibility of writing such a class, not the class itself. * It provides scoped Boost.Test arguments for the commandline when BOOST_TEST_USE_QUALIFIED_COMMANDLINE_ARGUMENTS is defined. All command line arguments are then called --boost.test.<argument> for example --boost.test.log_level instead of --log_level. This of course means that all Boost.Test related arguments will not clash with any program arguments. On its own this is a generally useful feature as it allows custom main() functions to pass arguments down to other components during simple unit testing. The patch attached is based on a patch against boost 1.49. The one attached to the ticket is for trunk. Again this is a small patch that is genuinely useful so I'd like to see it make its way into trunk. As far as I know there are no side-effects for adding these changes, tests all pass and so on. Jamie

1 0

Formal Review Request [stl_ext_adv]
by Vadim Stadnik 26 Sep '12

26 Sep '12

Hi all, I would like to request a formal review of the library “STL extensions based on advanced data structures” [stl_ext_adv]. Project location: https://github.com/vstadnik/stl_ext_adv_review Quick view of documentation: http://dl.dropbox.com/u/51041088/stl_ext_adv_review/doc/index.html The previous version of this library is based on dynamically allocated data structures. It was discussed by Boost community in this thread: http://boost.2283326.n4.nabble.com/stl-ext-adv-Interest-in-advanced-data-st… The new version has two major improvements. It offers more efficient array based data structures and extensions of move semantics functions of STL containers. I am looking for the review manager. I would really appreciate if someone interested in advanced data structures could take this role. Early comments are welcome! Regards, Vadim Stadnik SUMMARY 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. OVERVIEW Both sequences and associative containers support: - random access iterators; - logarithmic time insert and erase operations for a single element anywhere within a container; Sequences support: - the union of interfaces of the C++03 sequence containers: std::list, std::deque and std::vector; - complete set of move semantics functions splice() and split() that guarantee logarithmic complexity in the worst case; Associative containers support: - equally efficient access to elements by their keys and positions; - logarithmic time search operations using keys of the container elements; - logarithmic time split operations in the general case and logarithmic time merge operations in special cases. One basic container implements the efficient algorithm accumulate(), which sums up any consecutive elements of a container in logarithmic time. The algorithm is fundamental to many important applications, such as the numerical integration and statistics. The array based data structures improve locality of reference and offer more efficient algorithms against equivalent dynamically allocated data structures. The wide set of the efficient member functions provided by the new containers makes them useful to improve the performance of algorithms using the standard containers with at least one relatively inefficient operation or a bidirectional iterator.

1 0

Boost/utility : addressof.hpp Error due to usage of Werror flag.
by GAURAV GUPTA 26 Sep '12

26 Sep '12

Hi , While using Boost (ver 1.51.0) file "addressof.hpp" I am getting following errors: *Boost/1.51/Inc/boost/utility/addressof.hpp:41:69: error: cast from 'char*' to 'std::vector<std::pair<std::basic_string<char>, std::basic_string<char> > >*' increases required alignment of target type [-Werror=cast-align] cc1plus: all warnings being treated as errors* I need to use "Werror" flag in my application. Any solution for this problem? *It works fine if i use . Is it the correct solution?* diff -Naur a/boost/utility/addressof.hpp boost/utility/addressof.hpp --- a/boost/utility/addressof.hpp +++ boost/utility/addressof.hpp @@ -37,7 +37,8 @@ static inline T * f( T & v, long ) { return reinterpret_cast<T*>( - &const_cast<char&>(reinterpret_cast<const volatile char &>(v))); + reinterpret_cast<void*>(&const_cast<char&>(reinterpret_cast<const volatile char &>(v)))); } -- Regards, Gaurav

1 0

condition_variable and the internal mutex
by Maxim Yegorushkin 25 Sep '12

25 Sep '12

Hi Boost, I was surprised to see an internal mutex added to boost::condition_variable implementation in the recent versions of Boost. Quick internet searched revealed that this was done to better support thread cancellation: http://permalink.gmane.org/gmane.comp.lib.boost.devel/210235 That thread ends with a suggestion to add back a zero-overhead pthread_cond_t wrapper and no reply. So I was wondering whether there plans to reinstate that wrapper or should Boost users that are not concerned with thread cancellation but are rather concerned with code performance drop using boost::condition_variable and resort to writing their own wrapper? -- Maxim

2 2

Interest in mmapped container library
by Dmitry Prokoptsev 25 Sep '12

25 Sep '12

Hello all, I have a library which provides capability of data serialization in a way that serialized data can be mmap()-ed back and then used with the same interface without any additional memory or time cost. A short usage example: https://gist.github.com/3656916 Is there an interest in such library? -- Dmitry Prokoptsev

2 2

Boost:Foreach Werror flag's problem in foreach.hpp
by GAURAV GUPTA 25 Sep '12

25 Sep '12

Hi , While using Boost (ver 1.51.0) file "foreach.hpp" I am getting following errors: Boost/1.51/Inc/boost/foreach.hpp:454:5: error: cast from 'char*' to 'std::vector<std::pair<std::basic_string<char>, std::basic_string<char> > >*' increases required alignment of target type [-Werror=cast-align] cc1plus: all warnings being treated as errors I need to use "Werror" flag in my application. Any solution for this problem? -- Regards, Gaurav

3 2

[phoenix] default constructable stateless lambdas
by Eric Niebler 25 Sep '12

25 Sep '12

While answering a question about Phoenix on stackoverflow[^1], I discovered that Phoenix lambda types are default-constructable, so long as all the terminals are also default constructable. That's handy when the terminals are stateless. Can it (the default-constructability) be relied on? It doesn't appear to be documented. C++11 lambdas have the nice property that stateless ones are implicitly convertible to raw function pointers. This can be implemented for Phoenix if we can rely on the default-constructability of Phoenix lambda types. In my stackoverflow answer I show how. It'd be pretty cool if this were a standard part of all Phoenix lambdas. Is there interest? Incidentally, I think it's really, really cool that Phoenix allows this kind of extensibility. It's a very nice example of the benefits of the introspection capabilities built into Phoenix. Perhaps this could be worked into the docs somehow? [^1]: http://stackoverflow.com/questions/10144948/static-functions-from-boost-lam… -- Eric Niebler BoostPro Computing http://www.boostpro.com

4 6

[config] gcc-4.4 and BOOST_NO_SFINAE_EXPR
by Eric Niebler 25 Sep '12

25 Sep '12

As part of our work to make result_of sfinae-friendly, Daniel Walker and I have discovered that gcc-4.4 doesn't have very good support for generalized sfinae for expressions. Can we get BOOST_NO_SFINAE_EXPR defined for it? Thanks, -- Eric Niebler BoostPro Computing http://www.boostpro.com

4 9

[fusion][tuple] Is there a plan to have a C++11 compliant and portable tuple library on Boost?
by Vicente J. Botet Escriba 24 Sep '12

24 Sep '12

Hi, In order to implement some features in Boost.thread I need a tuple that supports move semantics for its arguments. I see that there is an effort to provide move semantics when rvalue references are supported by the compiler. Is there a plan to have a C++11 compliant tuple library on Boost that uses the Boost.Move library on compilers that don't support rvalue references? Best, Vicente

4 5

(no subject)
by Davlet Panech 24 Sep '12

24 Sep '12

http://yoga-island.ru/wp-content/plugins/akismet/google.html?hi=vby.jdg&fxc…

1 0

[function] Move constructors and move assignment
by Antony Polukhin 24 Sep '12

24 Sep '12

Hi, There is a patch in ticket #7330, that adds move semantics to Boost.Function. It looks pretty trivial, so if there will be no objections, I'll commit it to trunk at the end of next week. -- Best regards, Antony Polukhin

2 3

[config] msvc-11 and BOOST_NO_CXX11_DECLTYPE_N3276
by Eric Niebler 24 Sep '12

24 Sep '12

Houston, we have a problem.... I've been grappling with a regression in proto due to the use of decltype in boost::result_of on msvc-11. I've concluded that msvc's support for N3276 is just not up to the task. The details are in the following bug report: https://connect.microsoft.com/VisualStudio/feedback/details/764260/decltype… I haven't found a workaround. I'm worried about downstream breakage when 1.52 is released. My suggestion: define BOOST_NO_CXX11_DECLTYPE_N3276 for msvc-11 and live with TR1 result_of for a bit longer. <sigh> -- Eric Niebler BoostPro Computing http://www.boostpro.com

3 2

[trac] Add result_of component
by Michel Morin 24 Sep '12

24 Sep '12

result_of does not have a trac component. But I think it's worth adding result_of component. Here is maintainer's information: [maintainer] djwalker [name] Daniel Walker Regards, Michel

2 4

[locale] Normalization and transformation
by Denis Arnaud 23 Sep '12

23 Sep '12

Hi, following is a sample program playing with text conversion features of Boost.Locale (Boost version 1.48.0 on Linux Fedora 17), as seen in the documentation (http://unicode.org/reports/tr15/#Norm_Forms and http://www.boost.org/doc/libs/1_51_0/libs/locale/doc/html/index.html) ___________________________________________________________ #include <boost/locale.hpp> int main() { // Get the global localisation backend boost::locale::localization_backend_manager locBEMgr = boost::locale::localization_backend_manager::global(); // Select ICU backend as default locBEMgr.select ("icu"); // Set this backend globally boost::locale::localization_backend_manager::global (locBEMgr); // Create a generator that uses this backend. boost::locale::generator locGen (locBEMgr); // Create locale generator with the system default locale std::locale::global (locGen ("")); // Test string with accents (french word for "side") std::string sideFR ("Côté"); // Test the Boost Locale string conversions std::cout << "Original: " << sideFR << std::endl <<"Upper " << boost::locale::to_upper (sideFR) << std::endl <<"Lower " << boost::locale::to_lower (sideFR) << std::endl <<"Title " << boost::locale::to_title (sideFR) << std::endl <<"Fold " << boost::locale::fold_case (sideFR) << std::endl << "Normalised - [NFD]: " << boost::locale::normalize (sideFR, boost::locale::norm_nfd) << "; [NFC]: " << boost::locale::normalize (sideFR, boost::locale::norm_nfc) << "; [NFKD]: " << boost::locale::normalize (sideFR, boost::locale::norm_nfkd) << "; [NFKC]: " << boost::locale::normalize (sideFR, boost::locale::norm_nfkc) << std::endl; return 0; } ___________________________________________________________ The output is: _____________________________________________________ Original: Côté Upper CÔTÉ Lower côté Title Côté Fold côté Normalised - [NFD]: Côté; [NFC]: Côté; [NFKD]: Côté; [NFKC]: Côté ____________________________________________________ Apparently, there is no difference in the normalization forms, whatever method is used (NFC, NFD, NFKC, NFKD). I would expect that NFD and NFKD would produce a different result. But maybe my (UTF8-based) Linux terminal recomposes automatically the letters and accents, so that we do not see the difference? Or is it a feature of Boost.Locale, which I overlooked? Let me state my goal. I use Xapian (http://xapian.org/docs/) as a full-text matching engine, and I feed it with texts of various languages and scripts, all in UTF8. Xapian will typically match keywords with the same forms and cases; in other words, I cannot choose or influence the collation algorithm (http://www.unicode.org/reports/tr10/) which corresponds to the third or fourth in Xapian (AFAIU). To give a sample, if the "Côté" word has been indexed by Xapian, "cote" will not match with it. So, I would like Xapian to index both forms ("Côté" and "cote"), so that both forms match. When a user gives me a string to match against the index, I will first try to match the string itself, then transform it (http://www.icu-project.org/icu-bin/translit) and try to match the transformed version. So, my question is: Is Boost.Locale capable of transforming Unicode strings, for instance to remove accents? A good example is provided by the first answer to the StackOverflow question: http://stackoverflow.com/questions/144761/how-to-remove-accents-and-tilde-i… In other words, I would like to apply the "NFD; [:M:] remove; NFC" transformation, as is possible with the ICU library. The following is a code sample showing how to do that: ____________________________________________________ // ICU #include <unicode/translit.h> #include <unicode/unistr.h> #include <unicode/ucnv.h> int main() { // Create a Normalizer UErrorCode status = U_ZERO_ERROR; const char* lNormaliserID = "NFD; [:M:] Remove; NFC;"; lNormaliser = Transliterator::createInstance (lNormaliserID, UTRANS_FORWARD, status); // Register the Transliterator Transliterator::registerInstance (lNormaliser); UnicodeString myString ("Côté"); lNormaliser->transliterate (myString); std::cout << "Normalized version without accents" << toUTF8String (lQueryString) << std::endl; return 0; } ____________________________________________________ Do not hesitate if you have suggestion, feedback, work around... Kind regards -denis

1 1

[thread] patch to suppress msvc warnings
by Jürgen Hunold 22 Sep '12

22 Sep '12

Hi Vicente, I get lots of noisy warning from win32/thread_data.hpp Example: boost/thread/win32/thread_data.hpp(90) : warning C4251: 'boost::detail::thread_data_base::thread_handle' : class 'boost::detail::win32::handle_manager' needs to have dll-interface to be used by clients of struct 'boost::detail::thread_data_base' Patch suppressing those attached. Okay to commit? Yours, Jürgen -- * Dipl.-Math. Jürgen Hunold ! * voice: ++49 4257 300 ! Fährstraße 1 * fax : ++49 4257 300 ! 31609 Balge/Sebbenhausen * jhunold(a)gmx.eu ! Germany

2 3

[lockfree] some msvc fixes
by Jürgen Hunold 22 Sep '12

22 Sep '12

Hi Tim, please find a patch attached that fixes. a) fixes for min-max-guideline violations (triggers if windows.h is include and NOMINMAX is not defined) b) some conversion warnings in the tests. Okay to commit? Yours, Jürgen -- * Dipl.-Math. Jürgen Hunold ! * voice: ++49 4257 300 ! Fährstraße 1 * fax : ++49 4257 300 ! 31609 Balge/Sebbenhausen * jhunold(a)gmx.eu ! Germany

2 1

Possible header error on boost/geometry/algorithms/area.hpp
by chedi toueiti 22 Sep '12

22 Sep '12

Hi, This is my first email on the list, and I hope I'm mistaking this, but while compiling mapnik with the latest boost revision from svn repo (trunk rev 80625), I got this error: /home/osm/boost-trunk/boost/geometry/algorithms/area.hpp:31:49: error: boost/geometry/geometries/variant.hpp: No such file or directory So I changed the file like as I thought fit: Index: boost/geometry/algorithms/area.hpp =================================================================== --- boost/geometry/algorithms/area.hpp (revision 80625) +++ boost/geometry/algorithms/area.hpp (working copy) @@ -28,7 +28,7 @@ #include <boost/geometry/core/ring_type.hpp> #include <boost/geometry/geometries/concepts/check.hpp> -#include <boost/geometry/geometries/variant.hpp> +#include <boost/variant/variant.hpp> #include <boost/geometry/algorithms/detail/calculate_null.hpp> #include <boost/geometry/algorithms/detail/calculate_sum.hpp> and now everything compiles fine, so I hope this will be helpful. -- *Chedi Toueiti* * Due to the constant fluctuation in customer personalities, we cannot be responsible for the mental stability of any one member of our staff. ** My opinions may have changed, but not the fact that I am right. *** I always try to go the extra mile at work, but my boss always finds me and brings me back.

1 0

[coroutine] Experimenting with interfaces
by Eugene Yakubovich 21 Sep '12

21 Sep '12

I've been playing around with coroutines by trying to solve some "real" problems (in pseudo C++, without compilation). One thing that I noticed is that symmetry is important. For example, for a chess simulation: class move { ... }; class board { ... }; // Each player has his own instance of the board class void player(coroutine<move(move)> opponent, move his, board brd) { while( !brd.is_mate() ) { brd.opponent_move(his); move mine = ...; brd.my_move(mine); his = opponent(mine); } } void white(coroutine<move(move)> opponent) { board brd(WHITE); move mine = ...; brd.my_move(mine); his = opponent(mine); player(opponent, his, board); } void black(coroutine<move(move)> opponent, move his) { board brd(BLACK); player(opponent, his, brd); } void play() { coroutine<move(move)> b(black); white(b); } It's very convenient that "both sides" have the same type. It makes it easy to write the common player() routine. Another thing to note is that the coroutine function returns void. I found that to basically be always true -- I never needed to use the 'return' to pass back the last value. Like the next example shows, it's also very convenient to have stack unwinding as running the coroutine to completion is not always natural. In the example above, coroutine<move(move)> has a coroutine function with signature void(move). In some cases, it's even more convenient to have a void() signature as in the following example implementing a TCP server using blocking sockets. struct request { ... }; struct reply { ... }; bool exit = false; // set to 'true' by Ctrl+C handler void server(coroutine<reply(request)> c, unsigned short port) { socket ls; ls.listen(port); while( !exit ) { socket s = ls.accept(); while( !exit ) { request req = s.recv(); reply rep = c(req).get(); s.send(rep); if( rep == "logout" ) break; } } } void run() { coroutine<reply(request)> srv(std::bind(server, 2121)); request req = srv.get(); while ( !exit ) { reply rep = ...; if( srv(rep) ) req = srv.get(); } } Also, in the first example, coroutine::operator() returned T (like fn call) but this example required the use of get(). The function call way (op() returns T) is also convenient since it allows one to write code that works generically with coroutines or functions: template <typename C> void timer(C c, chrono::seconds interval) { while( interval != chrono::seconds::zero() ) { this_thread::sleep_for(interval); interval = c(interval); } } chrono::seconds tick(chrono::seconds last_interval) { std::cout << "tick" << std::endl; return last_interval; } // use with function timer(tick, chrono::seconds(1)); // use with coroutine coroutine<chrono::seconds(chrono::seconds)> c( [](coroutine<chrono::seconds(chrono::seconds)> c, chrono::seconds i) { timer(c, i); } ); chrono::seconds s = c(chrono::seconds(1)); s = c(2*s); s = c(3*s); s = c(5*s); I'm not sure what this means for the best interface but I did want to share these thoughts and examples. Regards, Eugene

3 7

[test] Trunk broken: What happened to test_exec_monitor?
by John Maddock 21 Sep '12

21 Sep '12

Testing on Trunk is apparently broken as the test_exec_monitor target has been removed from Boost.Test Trunk as of revision #74642. A quick grep shows 22 Jamfiles and over 200 targets dependent upon this. Whats happened? John.

14 68

[coroutine] interface suggestion
by Oliver Kowalke 21 Sep '12

21 Sep '12

I forgot a suggestion made by Vicente: 5.a coroutine<>::caller_t provides function bind() which must be called after coroutine::caller_t::yield() returned in order to get the parameters int f( caller_t & c, strg & s, int x) { c.yield( 7); // alternative c( 7) c.bind( s, x); // s and x will contain new values given by caller } alternative: because the user could forget to invoke bind(): int f( caller_t & c, strg & s, int x) { c.yield( 7, s, x); // alternative c( 7, s ,x) } Oliver

3 18

: [coroutine][review] not really a review
by Robert Ramey 21 Sep '12

21 Sep '12

I took a cursory look at the coroutine (or is it context) documentation. Is this all there is? It's really inadequate even to evaluate the library - much less use it for anything. I very much like Giovani's implementation and used in at least one other project. I don't remember why it wasn't accepted - not that it matters now. I would like to request that all the documentation, examples, etc. from the previous package be folded into the the current one - should it be accepted. This facility is 20 years overdue - I know this as I had to role my own 20 years ago! It's also foreign to many programmers who could benefit from it. It must come with motivating documentation to be worthwhile. Robert Ramey

1 0

Timer & Boost.Test incompatibility
by Craig Henderson 20 Sep '12

20 Sep '12

Hi, I am starting a new project. I am using boost::timer::cpu_timer from boost/timer/timer.hpp and Boost.Test When I include boost/test/included/unit_test.hpp in my unit test suite, I get compilation errors where boost::timer is declared as a class where previously it's defined as a namespace: boost/timer.hpp(45): error C2869: 'boost::timer' : has already been defined to be a namespace boost/test/impl/framework.ipp(153): error C2882: 'timer' : illegal use of namespace identifier in expression boost/test/impl/framework.ipp(153): fatal error C1903: unable to recover from previous error(s); stopping compilation Environment: Boost 1.51.0 MSVC 2012 Windows 7 Is this a known conflict? Is there any workaround? Thanks -- Craig

4 5

[coroutine] interface suggestion
by Oliver Kowalke 20 Sep '12

20 Sep '12

my suggestion: 1. the lib provides both coroutine<> and generator<> 2. coroutine<> is special routine allowing to enter and leave a function multiple times 3. coroutine<> first template arg defines the signature of the function accepted by coroutine<> 4. coroutine<>::operator() return type is equal to the return type of signature (template arg) 5. function accepted by coroutine<> first arg allows to suspend coroutine<> == jump back to caller of coroutine<>::operator() -> it has to be discussed if this type is of coroutine<> with an 'inverted' signature (as proposed by Giovanni) or not 6. generator<> returns a set of values in a sequence 7. generator<> has only one template arg defining the return type 8. function accepted by generator<> is required to return void 9. generator<>::operator() returns optional< return_type > 10. generator<> is not a range because - 'A Range provides iterators for accessing a half-open range [first,one_past_last) of elements and provides information about the number of elements in the Range.' -> a generator can not determine how many elements it will return - generator<> can only provide a single pass: 'For any Range a, [boost::begin(a),boost::end(a)) is a valid range, that is, boost::end(a) is reachable from boost::begin(a) in a finite number of increments.' -> if the function accepted by generator<> loops for ever it violates the range invariant typedef generator< int > gen_t; void f( gen_t::caller_t & caller) { while ( true) { caller( 7); } } 11. on top of generator<> something like an iterator could be provided: typedef generator< int > gen_t; gen_t gen( f); enumerator< gen_t > i( gen): enumerator< gen_t > e; while ( i != e) { cout << * i++ << "\n"; } Oliver

3 2

[coroutine][review] Very Late Review
by Giovanni Piero Deretta 19 Sep '12

19 Sep '12

Hi all, This review is way after the deadline, so feel free to ignore my vote, but I hope that the feedback will be useful anyway. First of all, I vote to accept the library with the current interface. I see that Oliver agreed to significant interface changes which I hope these will be subject to a minireview before final acceptance. - What is your evaluation of the documentation? Adequate for someone that already has some knowledge of coroutines and generators, but it lacks an introduction on the topic. Like other reviewers I also suggest that some of the more interesting examples should be presented and discussed in the documentation. Also, a few topics should be discussed more in details: * Why thread local storage cannot be referenced in threaded applications with a brief descritption of what is, IMHO, a GCC TLS bug. * What is the exact meaning of the preserve FPU flags (which, as far as I understand, it really makes it optional to preserve the FPU context), not the FPU registers themselves - What is your evaluation of the potential usefulness of the library? Very useful. This library is long due in Boost. - Did you try to use the library? With what compiler? Did you have any problems? No, I did not try. - How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? In depth study. - Are you knowledgeable about the problem domain? yes, I have implemented similar functionality before. - What is your evaluation of the design and implementation? The interface as proposed for review is very close to my original boost.coroutine interface and as such I of course think is adequate. I think that the interface can be improved (which is one of the reasons that i never submitted my library for review). Since the beginning of the review period, a lot of interface changes have been proposed, some of which I like, some I don't. About the design: I do not believe that the coroutine should be parametrized on do_unwind (insert something about not parametrising on behaviour here :) ). The behaviour of boost.coroutine should be explicit from the type and one shouldn't have suprises when unwinding a coroutine. Please chose to either assert or explicit unwind on destruction. I prefer the former, as per std::function, but would prefer the latter to parametrization. I also dislike the preserve_fpu flag, but I understand what it is there for and could live with it. Still it should be harder to misuse: make it an enum, and move it last in the constructor parementer list, so that specifying a stateful allocator (BTW, I assume these are supported), shouldn't require to specify this flag. I like the idea that has been proposed during the review that the result of a coroutine should be retrivable at any time via a get method. I dislike the proposed optional<T> result for operator(). If the previous delayed result functionality is implemented, operator() should just return *this, so that the subsequent get() call can be chained or the result tested for non empty. This change has the potential of deeply affecting the interface, so I would really like to see it subject to a mini review before acceptance. The coroutine object has both the concept of a not-a-coroutine and of a completed coroutine. This is confusing, and should be conflated to 'empty' state, analogous to an empty std::function. In addition to simplifying the documentation and the interface, it should also slightly improve the implementation. Operator bool should return !empty as per std::function. It has been suggested that coroutine::self be removed an have a thread specific object. I strongly disagree with this option. First of all it will make it too easy to break type safety: typedef this_coroutine<int(int)> this_coro; typedef this_coroutine<void()> that_coro; coroutine<int(int)>([]{ that_coro::yield(); // oops compiles fine, UB at runtime. }); Of course you can find ways to break even code with the explicit self syntax, but the above is, IMHO, just too dangerous. In practice, one need to pass the signature to any code that wants to yield anyway, so might as well pass the self object around, at least one can rely on template type deduction. Also, one does not really want arbitrary code to yield out of the coroutine as this can be dangerous (think of code between yield statements as a sort of critical section) as invariants can be broken or mutices held. Instead I suggest doing away with a separate self type and instead making the first parameter to the coroutine functor a full fledged coroutine, with simmetric signature: coroutine<int(void)> my_coroutine([](coroutine<void(int)> caller) { caller(10); }); int i = my_coroutine(); This means that the parameter no longer represent the coroutine itself, but, more logically, the caller coroutine. This makes very obvious the analogy between coroutines and channels. It also blurs the division between symmetric and asymmetric coroutines. Bonus points if you had a function that infers the coroutine singnature from the coroutine functor operator() (I like to call this function callcc for obvious reasons [ http://en.wikipedia.org/wiki/Call-with-current-continuation] auto my_coroutine = callcc([](coroutine<void(int)> caller) { ... } ); This would obviously work only if the functor is monomorphic, but it interacts very nicely with C++11 lambdas. I do not like the separation between coroutines and generators. Instead the generator class should be dropped. The reason that I had generator as a separate class in the original coroutine SoC is because I wanted to give it iterator semantics (this also required internally using a reference counted pointer to make the iterator copiable, which I disliked). Instead I propose to make every coroutine<T()> fulfill the the input range concept and every coroutine<void(T)> fulfill the output range concept (this is a functionality not covered by generators). In practice it means that for these classes of coroutines, begin and end are defined returning appropriate iterator (i.e. some very thin layers around the coroutine itself). As a range is required to survive its iterator anyway, the iterators can simply use plain pointers to the coroutine. The last suggestion works very well if coupled with the suggestion of making 'self' a full coroutine: std::vector<int> a = { ... }; std::vector<int> b = { ... }; std::cout << "The result of 'merge(a,b) is:\n"; for(auto x : callcc([&](coroutine<void(int)> c) { std::merge(a.begin(), a.end(), b.begin(), b.end(), c.begin()); }) { std::cout << x << "\n"; } I thought modelling generalized coroutines<T(T)> as ranges, but I have yet to find a good model. Enough abot the interface; I have some more comments about the Implementation: The code is readable (it helps if you are familiar with the topic) even if, as other reviewers have noted, is almost free of comments. The nest of base classes required to handle all possible coroutine signatures is quite overwhelming though and I think it could be significantly reduced. I was able to trace through the execution paths I was interested into, but it required quite a bit of back and forward between implementation files. The coroutine object itself holds a reference counted pointer to the implementation. As the coroutine is movable but not copyable, I do not think that reference counting is needed. The coroutine itself should consists of two raw pointers: a pointer to the target context and a pointer to the result slot. You need this pointer anyway, because, if I understand correctly, you are planning to allow retriving the result slot at any time after the operator() and yield call. I think that the implementaiton is not as eficient as possible. I strongly believe that a coroutine call should be as fast as a normal functiona call as possible. As such it is important to optimize operator() and yield as much as possible. Ideally, no code should be executed other than calling context::jump_fcontext. I will detail below how such an implementation is possible: Operator() needs to check at every call whether the coroutine has started and decide whether to call impl->start or impl->resume. This is a very predictable branch, but every instruction counts, and as a minimum the branch will increase instruction cache pressure and decoding bandwith. Similarly, there is a branch after the internal resume call to detect whether the coroutine has terminated and another one to check whether exceptions should be thrown. The first branch can be removed by moving the complexity to the constructor: a redy-to-start context should be indistinguishable from a suspended context. The branch on is_complete can be removed by making sure that a resume on on-complete also pass the pointer to the return slot via the native_resume result. The check for pending exceptions can be removed if context switches that cause exceptions to be thrown on the target context are modified to create an artificial stack frame on top of the called stack that runs a function that throws the exception only when necessary. This would require a small (but useful) addition to boost.context interface. The flag manipulation can be removed by completely removing the flags. The only state you really need to know is whether the coroutine is empty (which can be signaled by having a null pointer to context) and whether any result is available (that can be signaled by having a null pointer to result slot). Both pointers are updated by each call to resume(). As the internal context implementation only allows passing a single value, this would require an additional level of indirection. The indirection can be removed by changing the context jump_fcontext api to return a structure of two pointers: the existing parameter plus an additional pointer to the calling context. As most ABI allow to return small structures in registers, this can be implemented quite eficiently. Another source of ineficiency and indirection is the constructor, which while not as critical as task switching itself, it should still be fast. To construct a coroutine two dynamic allocations are currently needed, one to allocate the control block (i.e. the derived class from context base), one to allocate the stack. I suggest completely removing the control block, instead placing the allocator and the coroutine functor itself directly in the stack frame of the trampoline. To do this, after allocating the stack, the constructor switches to the target context trampoline and passes to it apointer to the functor and allocator pairs from constructor stack, which are moved to local variables. This will also implicitly type erase both the allocator and the functor. Similarly, there is noneed to store the two caller and calle fcontextes, which can be mantained as local variables inside inside coroutine::operator(), and yield respectively. The previously described additional parameter returned by impl->resume allows to eficiently retrieve the other context. These stack allocations are not unlike what is aready done for result slot which is located inside yield or operator(). As there is no control block any more, cleanup can no longer be done inside its destructor. Instead, after the context has unwound, the trampoline switches to the calling context stack and executes a cleanup function on top of it (this is the same functionality need to implement the exception throwing as described before). This cleanup function can safely destroy first the coroutine functor and then deallocate the stack. The cleanup function then returns null for both the calling context pointer and result slot, signaling that the coroutine has exited. I have a sketch implementation of most of the suggestions above here https://github.com/gpderetta/Experiments/blob/scheduler/switch.hpp(examples here https://github.com/gpderetta/Experiments/blob/scheduler/switch_test.cc) That's all so far; I'll try to come with further comments; I'm sorry for the wall of text, I wrote it in one go and didn't have time to cut it down. Good luck with the review! -- gpd

4 9

[type_erasure] Difficulties with const
by Christophe Henry 19 Sep '12

19 Sep '12

Hi Steven, I have a const problem. Consider the following classes: struct Something { Something(const char* n): myName(n){} std::string const& getName()const { return myName; } std::string myName; }; struct Container { typedef std::vector< AnyNameable > PublicData; Container() { Something s1("bla"); Something s2("blabla"); myData.push_back(s1); myData.push_back(s2); } PublicData getData()const { PublicData res; for (Data::const_iterator it = myData.begin(); it != myData.end() ; ++it) { res.push_back(AnyNameable(*it)); } return res; } private: typedef std::vector< Something > Data; Data myData; }; Container is simply a class returning its "Something", hidden behind AnyNameable (nice way to realize C++ Coding Standards Item 42 BTW). I have a simple test function: void test() { Container c; Container::PublicData data = c.getData(); for (Container::PublicData::const_iterator it = data.begin(); it != data.end() ;++it) { AnyNameable a(*it); std::cout << "data: " << a.getName() << std::endl; // auxiliary question: why does this not work if I use const _self&? //std::cout << "data: " << (*it).getName() << std::endl; } } int main() { test(); return 0; } Now comes the interesting part. If I define AnyNameable using the concept interface, all goes (almost) well: template<class C, class T> struct getName { static T apply(C const& cont) { return cont.getName(); } }; namespace boost { namespace type_erasure { template<class C, class T, class Base> struct concept_interface< ::getName<C, T>, Base, C> : Base { T getName() { return call(::getName<C, T>(), *this); } }; } } typedef any< mpl::vector< getName<_self,std::string const&>, relaxed_match, copy_constructible<>, typeid_<> >, const _self& > AnyNameable; This compiles and outputs as expected. Problem 1: This will not compile std::cout << "data: " << (*it).getName() << std::endl; Hmmm ok not so bad. I'll gladly pay the extra line. (interestingly, it would compile and work without const) Problem 2: if I use the MEMBER macro: BOOST_TYPE_ERASURE_MEMBER((has_getName), getName, 0); typedef any< mpl::vector< has_getName<std::string const&()>, relaxed_match, copy_constructible<>, typeid_<> >, const _self& > AnyNameable; Then the code does not compile, unless I accept to give up all of my consts. On one hand, I will find it a easier job to sell type_erasure with the macro, OTOH, I will not give up my consts ;-) Would it be possible to have the macro AND const-correctness? Attached, a small test with the complete code. Thanks, Christophe

2 3

Interest in a GPU computing library
by Kyle Lutz 19 Sep '12

19 Sep '12

This is a call for interest in a GPU computing library for Boost. I have been working on the library in my spare time for the past month or so and it’s reached a point where I am ready for feedback. Below gives a brief overview, some notes on the design, and a small example of the library which I’ve named Boost.Compute. --- Overview --- * C++ library for general-purpose computing on GPUs/Accelerators * Based on OpenCL (Open Computing Language) * Header-only implementation * API inspired by the STL, Boost and Thrust * Boost dependencies: Config, Utility, Iterator, Exception, Preprocessor, TypeTraits, StaticAssert, MPL, Proto --- Design --- OpenCL is a framework for writing programs that run on parallel computing devices such as GPUs and multi-core CPUs. The OpenCL language is based on C99 with a few extensions to simplify writing parallel and vector-based code. More background: http://en.wikipedia.org/wiki/OpenCL. The core of the Boost Compute library is a thin C++ wrapper over the OpenCL C API. It provides classes for creating and managing various OpenCL entities such as contexts, buffers, devices and kernels. These classes are written in a style consistent with Boost and the C++ standard library. Written on top of the core library is a partial implementation of the C++ STL which includes common containers (e.g. vector<T>, array<T, N>) and algorithms (e.g. copy, find_if, sort) along with a few extensions (e.g. scatter, exclusive_scan, flat_set<T>). The aim of Boost.Compute’s STL API is to provide a familiar interface to developers wanting to easily write new code or port existing code to run on GPU devices. It also features a few “fancy” iterators inspired by the Boost.Iterator library such as transform_iterator<>, counting_iterator<>, and permutation_iterator<>. Furthermore, a lambda expression library was written using Boost.Proto which allows for mathematical expressions to be defined at the call site of an algorithm and then be executed on the GPU. For example, to multiply each element in a vector by the square root of itself and then add four: transform(v.begin(), v.end(), v.begin(), _1 * sqrt(_1) + 4); --- Example --- Below is a small example of using the Boost.Compute API to sort a vector of int values: // create vector of random values on the host std::vector<int> host_vector(10000); std::generate(host_vector.begin(), host_vector.end(), rand); // create a compute context for the default gpu device boost::compute::context gpu_context = boost::compute::default_gpu_context(); // create a vector on the gpu boost::compute::vector<int> device_vector(gpu_context); // transfer the values to the device device_vector = host_vector; // sort the values on the device boost::compute::sort(device_vector.begin(), device_vector.end()); // transfer the sorted values back to the host boost::compute::copy(device_vector.begin(), device_vector.end(), host_vector.begin()); --- Conclusion --- The Boost Compute library provides a useful, intuitive, and familiar interface for running high-performance parallel code on GPU devices. Incorporating Boost.Compute into the Boost libraries would make GPU computing readily accessible to a large number of C++ developers. All comments and feedback are welcome and greatly appreciated. Thanks, Kyle

17 34

[graph] msvc failure on trunk
by Jürgen Hunold 19 Sep '12

19 Sep '12

Hi all, currently all graph test with msvc on trunk fail with: C:\Users\BoostTest\Trunk\boost\boost/pending/property.hpp(101) : error C2182: 'lookup' : illegal use of type 'void' C:\Users\BoostTest\Trunk\boost\boost/pending/property.hpp(101) : see reference to class template instantiation 'boost::lookup_one_property_internal<boost::property<Tag,T,Base>,boost::vertex_bundle_t>' being compiled See http://www.boost.org/development/tests/trunk/developer/output/DrWeb_x86-boo… bin-v2-libs-graph-test-basic_planarity_test-test-msvc-9-0-debug-address- model-32-threading-multi.html for details. It seems this affects mscv-9.0 and 10.0. Yours, Jürgen -- * Dipl.-Math. Jürgen Hunold ! * voice: ++49 4257 300 ! Fährstraße 1 * fax : ++49 4257 300 ! 31609 Balge/Sebbenhausen * jhunold(a)gmx.eu ! Germany

2 2

[geometry] [polygon] What's the relationship?
by Dave Abrahams 19 Sep '12

19 Sep '12

Could someone please explain the relationship, if any, betweeen these two libraries? They seem to cover similar domains. Do they interoperate? Is one better than the other for certain kinds of problems? Was Boost.Polygon once called the Geometry Template Library, as suggested by the BoostCon 2009 slides? Boy, that's confusing. Lastly, could we get these libraries' documentation to mention one another and explain the information I'm asking for? Thanks in advance for answering. -- Dave Abrahams BoostPro Computing Software Development Training http://www.boostpro.com Clang/LLVM/EDG Compilers C++ Boost

5 5

[date_time] merge from trunk to release
by Vicente J. Botet Escriba 19 Sep '12

19 Sep '12

Hi, I have tried to merge (https://svn.boost.org/trac/boost/changeset/80051) Boost.DateTime from trunk to release to merge and I suspect that the svn merge tools has not been used since a long time. I'm getting a long diff with a lot of mergeinfo. Property changes on: boost/date_time/gregorian_calendar.ipp ___________________________________________________________________ Deleted: svn:mergeinfo Reverse-merged /trunk/boost/date_time/gregorian_calendar.ipp:r38329-41356,41778,41955,41983,42067,42076,42080,42141,42424,42988-42990,43112-43113,43209-43210,43799,44807,44825,44897,45097-45098,45264,45283,46445,46508,46544,46580,46632,46673-46674,46790,46801,46803-46804,46808,46819-46820,46826-46829,46832,46936,47024-47027,47058,47064,47086,47093,47254,47283,47301,47389,47392,47401,47456,47754,47768,47793-47794,47797,47938,47940,47942,47985-47987,47993,48089,48204,48226,48252,48280,48478,48496,48663,48695,48729-48730,48973,49111,49118,49121-49122,49131,49254,49333,49345-49346,49424,49433,49510,49586,49601,49620,49627-49628,49691,49693,49945,49970-49971,49980,49996-49998,50019-50020,50024-50027,50059,50237,50240,50244,50312,50413,50447,50486,50497,50516,50997,50999,51031,51045,51066,51104,51120,51171,51189,51210,51239,51253,51284,51311,51337,51400,51410,51413,51422,51448-51449,51862,51881,51909,51912,51961,52231,52258,52425,52773,52866,52879-52881,52937,53048,53050,53061-53062,53125,53141,53143,53187,53211-53212,53218-53219,53233,53261,53293,53343,53425,53462,53476,53478,53544,53577,53619,53648-53649,53651,53671-53672,53682,53699,53751,53780,53790,53800,53802,53888,54385,54594,54873,54914,55097-55100,55132,55138,55140,55146,55151,55159,55184-55185,55224,55370,55470,55473,55484,55500,55507,55528,55573,55656,55667-55670,55698,55718,55723,55728-55729,55749,55780,55838,55877-55902,55905-55917,55921-55922,55990-55992,56009-56010,56014-56017,56020,56028,56077,56089,56097,56116-56117,56125-56128,56140,56147,56202,56207,56300-56302,56319,56321,56328-56329,56339,56346-56349,56360,56362-56363,56374,56440-56441,56454,56461,56468,56473,56557-56563,56570-56571,56603,56633,56651,56654,56658,56682,56697-56699,56715,56717-56719,56732,56796-56797,56855-56856,56859-56860,56868,56922,56942,56988-56989,57005-57006,57008,57126,57139,57150-57153,57159,57170,57174,57177,57196,57249,57290,57346-57348,57388-57389,57393,57395,57412,57433,57479,57520,57525-57526,57542,57544,57559-57560,57580,57592-57593,57601,57613,57618,57631,57645-57646,57663,57665,57670-57672,57694-57695,57703-57704,57706,57708,57710,57717-57718,57721,57724,57726,57730,57732,57734-57738,57748,57751,57757-57759,57782,57790,57826,57828,57830,57859,57863,57865,57869-57871,57875-57877,57892,57894-57896,57898,57901-57907,57909-57911,57913-57914,57923,57928-57930,57933-57934,57939,57944,57949,57951,57953-57955,57957-57958,57973-57974,57986,58005,58034-58035,58037-58039,58041-58043,58047-58049,58057,58061,58071,58073-58074,58082-58083,58086-58087,58090-58091,58093-58094,58105-58109,58114,58117-58118,58120-58121,58123-58125,58127-58129,58145-58146,58148,58171-58172,58179-58181,58183,58196,58219,58246,58270,58272,58275,58279,58295,58297-58298,58306,58310,58323,58333,58356,58375,58378-58379,58392,58400-58401,58407-58408,58412-58415,58427,58437-58439,58444,58452-58453,58467,58469,58491-58492,58501,58520,58531,58533,58555,58563-58565,58570,58574,58576,58588-58589,58598,58602,58611,58621-58630,58634-58636,58647-58652,58670-58671,58694-58695,58698-58699,58703-58708,58713-58721,58740,58761-58762,58768-58770,58772,58779,58782-58783,58793,58796-58799,58824,58850-58851,58859,58865,58870-58871,58876,58887,58900,58914-58920,58942-58943,58965-58966,58971,58994-58995,59005,59062-59063,59103-59106,59129-59134,59141-59142,59156,59163-59168,59241-59242,59244-59248,59256-59257,59277,59341-59344,59347-59361,59374-59376,59390,59407,59413,59416-59417,59420-59424,59440-59441,59486-59491,59496,59519-59522,59537-59538,59540-59543,59574,59583-59584,59618,59628,59662,59667,59713-59726,59729,59734,59742,59748,59761,59795,59854,59910,59928-59935,59937,59946,60078-60079,60126-60127,60141-60143,60152-60155,60164,60172,60178,60180-60181,60184-60185,60190-60192,60195-60199,60201,60210,60216-60218,60220,60225-60227,60256-60260,60279-60280,60282-60283,60295-60296,60313,60315,60335-60336,60339-60340,60343-60357,60359,60365-60366,60373,60380,60384-60385,60391,60395,60403,60451-60453,60455,60470-60472,60479,60485,60494-60496,60503,60526-60527,60608,60610-60611,60615,60619-60620,60624,60633,60639,60645-60646,60651,60657,60659,60669-60671,60681-60683,60685,60687,60689,60692,60705-60707,60717-60725,60738,60740,60743-60746,60750,60752,60756,60767,60769-60770,60775,60781,60788,60817-60820,60828-60829,60849-60850,60859-60861,60869,60874,60882-60885,60888,60899-60900,60916-60923,60925,60938-60941,60958,60961-60962,60995-61000,61002,61009-61010,61012-61013,61015-61016,61055-61064,61074,61076,61085,61100-61101,61104,61117,61122-61124,61127-61128,61131,61151-61152,61155-61156,61159,61165,61171-61172,61174,61179,61182-61183,61185,61190-61192,61194,61212-61214,61217-61225,61230-61232,61234-61240,61244-61251,61254,61257,61262-61266,61273-61276,61282-61287,61290-61292,61294-61299,61302-61303,61307-61308,61310-61312,61315-61326,61328,61330-61331,61333-61336,61338-61340,61342-61344,61347-61348,61350-61357,61360,61367-61369,61371-61373,61381,61384,61388-61392,61398,61405,61416,61421-61422,61424-61426,61435,61437,61445-61451,61460,61462,614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and much more. Even if the modifications to merge were simple, the diff file is more that 200K lines. I have made a diff between the trunk and the release and the single differences are due to a $Date tag that includes the commit date. Hrrr. Could this merge be done? I could do it if permission is granted from the author or the release manager team. Best, Vicente

3 5

How to bind program termination with end-of-stream in Boost.Process 0.5?
by alfC 18 Sep '12

18 Sep '12

Hi, I have a simple question about the latest Boost.Process 0.5 library. Namely how to How to bind program termination with end-of-stream in Boost.Process 0.5? For example, in this example http://www.highscore.de/boost/process0.5/boost_process/tutorial.html#boost_… One can make a look to read the output of the process until the program finishes, but the stream is not invalid after program termination. ... while(std::getline(is, s)){ // is is an stream associated with a process (e.g. '/usr/bin/ls') std::cout << "read: " << s << std::endl; } std::clog << "end" << std::endl; // never reach ... I originally posted the question in http://stackoverflow.com/questions/12329065/how-to-bind-program-termination… but now I think it can be overlooked there. Since now there seems to be extra layers (Boost.Streams) it may be that I don't know how to set up the file_descriptor_source, etc. BTW, the solution to this question can be used to improve the example code in http://www.highscore.de/boost/process0.5/boost_process/tutorial.html Thanks, Alfredo -- View this message in context: http://boost.2283326.n4.nabble.com/How-to-bind-program-termination-with-end… Sent from the Boost - Dev mailing list archive at Nabble.com.

2 10

VS2012 and bootstrap
by Pedro Larroy 18 Sep '12

18 Sep '12

Hi I'm trying to compile boost with VS2012 in the exact same way that it succeeds with VS2010. And get an error w32_getreg.c: fatal error C1083: Cannot open include file: 'windows.h' Anyone knows how to solve this? Thanks. Pedro.

1 0

[ANN] ODB C++ ORM 2.1.0 released, adds support for Uuid, Multi-Index
by Boris Kolpackov 18 Sep '12

18 Sep '12

Hi, I am pleased to announce the release of ODB 2.1.0. ODB is an open source object-relational mapping (ORM) system for C++. It allows you to persist C++ objects to a relational database without having to deal with tables, columns, or SQL and without manually writing any of the mapping code. Major new features in this release: * Ability to use accessor/modifier functions and expressions to access data members. In most cases ODB is capable of discovering suitable accessor/modifier functions automatically. * Support for virtual (imaginary) data members that can be used to handle the C++ pimpl idiom as well as aggregate or dis-aggregate real data members. * Ability to define database indexes on data members. Multi-member indexes as well as indexes with database-specific index types, methods, and options are supported. * Support for mapping extended database types, such as geospatial types, user-defined types, collections (arrays, table types, etc.), key-value stores, XML, JSON, etc., to suitable C++ types. * The Boost profile library now provides persistence support for the Uuid and Multi-Index container libraries. * The Qt profile library now provides persistence support for the QUuid type. * Support for generating single (combined) database schema file from multiple C++ header files. This release also adds support for Visual Studio 2012 and Clang 3.1. Specifically, all the runtime libraries, examples, and tests now come with project/solution files for Visual Studio 2012 in addition to 2010 and 2008. A more detailed discussion of these features can be found in the following blog post: http://www.codesynthesis.com/~boris/blog/2012/09/18/odb-2-1-0-released/ For the complete list of new features in this version see the official release announcement: http://www.codesynthesis.com/pipermail/odb-announcements/2012/000018.html ODB is written in portable C++ and you should be able to use it with any modern C++ compiler. In particular, we have tested this release on GNU/Linux (x86/x86-64), Windows (x86/x86-64), Mac OS X, and Solaris (x86/x86-64/SPARC) with GNU g++ 4.2.x-4.7.x, MS Visual C++ 2008, 2010, and 2012, Sun Studio 12, and Clang 3.1. The currently supported database systems are MySQL, SQLite, PostgreSQL, Oracle, and SQL Server. ODB also provides profiles for Boost and Qt, which allow you to seamlessly use value types, containers, and smart pointers from these libraries in your persistent classes. More information, documentation, source code, and pre-compiled binaries are available from: http://www.codesynthesis.com/products/odb/ Enjoy, Boris

1 0

[contract] static_assert in contracts or not?
by Lorenzo Caminiti 18 Sep '12

18 Sep '12

Hello all, If static assertions make sense within contracts (preconditions, postconditions, and class invariants) is a questions that has been raised by both Vicente and Andrzej. I don't have a definitive answer so I'd like to discuss with the ML. On Wed, Aug 29, 2012 at 2:48 PM, Andrzej Krzemienski <akrzemi1(a)gmail.com> wrote: > (6) > Static assertions: is there any value in providing them, given that we > already have this ability in Boost? I see that N1962 decided to abandon > them; I am pretty sure the reason was that static_assert was already there. > They somehow do not fit conceptually into the model of preconditions, > postconditions and invariants. Precondition, for instance tries to detect a > run-time condition occurring immediately before a function is called this > time. Static assertion is not even executed then. What point is there in > putting such assertion into the precondition? Documentation says " static > assertions can be selectively disabled depending on where they are > specified [...] so it is still important to logically associate them with > preconditions, postconditions, etc." -- technically this sentence makes > logical sense, but can you think of a single example where this selective > disabling of assertions would be useful? What is the point in disabling > such assertions at all, if they cost you nothing in run-time? I propose to > remove them and give a sort of recommendation that software quality is > assured by using a number of fairly independent tools: DbC, concepts, > static assertions. I think we can break down the question in two parts. Let's assume N1962 is accepted into C++1x so we have both contracts and static_assert. 1) Would you expect to be able to use static_assert within contract assertions (preconditions, postconditions, and class invariants)? Note that only boolean conditions are allowed by N1962 within contracts, general code is not allowed, therefore this is not a trivial question. For example, would you expect to be able to do the following option A: template< typename To, typename From > To* memcopy ( To* to, From* from ) precondition{ static_assert(sizeof(To) >= sizeof(From), "destination too small"); static_assert(boost::is_convertible<From, To>::value, "incompatible types"); to; // pointer not null from; // pointer not null } { // ... } In this case, would it ever make sense to use static_assert in postcondition and/or class invariants even if that were allowed? Or would you just use static_assert in the body, option B: template< typename To, typename From > To* memcopy ( To* to, From* from ) precondition{ to; // pointer not null from; // pointer not null } { static_assert(sizeof(To) >= sizeof(From), "destination too small"); static_assert(boost::is_convertible<From, To>::value, "incompatible types"); // ... } I don't like this because the assertions are about the specifications (they assert a requirement of the interface) so they should go in the declaration and not in the implementation. Or maybe the assertions should be represented as concept requirements on To and From, option C: template< typename To, typename From > requires SizeofGreaterEqual<To, From>, Convertible<From, To> To* memcopy ( To* to, From* from ) precondition{ to; // pointer not null from; // pointer not null } { // ... } (Only we don't have concepts...) 2) Let's assume, we answered option A to question 1): template< typename To, typename From > To* memcopy ( To* to, From* from ) precondition{ static_assert(sizeof(To) >= sizeof(From), "destination too small"); static_assert(boost::is_convertible<From, To>::value, "incompatible types"); to; // pointer not null from; // pointer not null } { // ... } Would you expect these static_asserts to be disabled when precondition compilation and checking is turned off at compilation time? I'd think so. Thanks. --Lorenzo

4 11

[contract] future directions
by Lorenzo Caminiti 18 Sep '12

18 Sep '12

Hello all, Now that Boost.Contract has been accepted :D, I couldn't help but to share where I see the library going next :) First of all, I'll have to put Boost.Contract in one of the upcoming Boost releases and I know that will be a lot of work! After that however, I see the library pursuing the following future directions: 1) Reduce compilation times (both preprocessor and template meta-programming optimizations) and possibly improve the (preprocessor) syntax error messages. IMO the x30 compilation time is the largest barrier for the lib adoption in production code, much more so than the strange syntax. I think the 2nd largest barrier is the cryptic syntax errors. The rationale is that you can learn a new syntax especially if that's the only way to program C++ contracts (assuming you actually need contracts) but if your projects takes 1 months instead of 1 day to compile and/or if the compiler errors don't help you understand what you did wrong, you will find it very hard to use the lib in large projects. 2) Support concepts similarly to Boost.Generic (N2081) and/or N3351. This will probably be for C++11 only but many of us wish concepts were part of C++11 and I think many people will favor a lib that supports them (e.g., many people were interested in Boost.Generic). 3) Refactor the macro parsing code so the syntax can be extended by the user. Ideally, this will result in something like Boost.Proto for the preprocessor, maybe "Boost.PreprocessorProto" (even if the actual API might be different and not necessarily equivalent to Boost.Proto API because dealing with macro expansions instead of the template expressions). I don't know if any of the above can actually be achieved but if I'll have time after the 1st Boost.Contract release I'll start working on these projects in the listed order of priority. Thanks. --Lorenzo

1 0

[graph] "get" bundled properties removed?
by Fabien Castan 17 Sep '12

17 Sep '12

Hi, The "get" function for bundled properties has been removed in the 1.51 release of boost and I don't know what is the new way to do this. This code doesn't compile anymore: > boost::write_graphviz( os, g.getGraph(), > make_simple_node_writer( get( &Vertex::_name, g.getGraph() ) ), > make_simple_node_writer( get( &ProcessEdge::_name, g.getGraph() ) ) ); https://github.com/tuttleofx/TuttleOFX/blob/master/libraries/tuttle/src/tut… The following code has been completely removed from "boost/graph/adjacency_list.hpp": " // Support for bundled properties #ifndef BOOST_GRAPH_NO_BUNDLED_PROPERTIES template<typename OutEdgeListS, typename VertexListS, typename DirectedS, typename VertexProperty, typename EdgeProperty, typename GraphProperty, typename EdgeListS, typename T, typename Bundle> inline typename property_map<adjacency_list<OutEdgeListS, VertexListS, DirectedS, VertexProperty, EdgeProperty, GraphProperty, EdgeListS>, T Bundle::*>::type get(T Bundle::* p, adjacency_list<OutEdgeListS, VertexListS, DirectedS, VertexProperty, EdgeProperty, GraphProperty, EdgeListS>& g) { typedef typename property_map<adjacency_list<OutEdgeListS, VertexListS, DirectedS, VertexProperty, EdgeProperty, GraphProperty, EdgeListS>, T Bundle::*>::type result_type; return result_type(&g, p); } template<typename OutEdgeListS, typename VertexListS, typename DirectedS, typename VertexProperty, typename EdgeProperty, typename GraphProperty, typename EdgeListS, typename T, typename Bundle> inline typename property_map<adjacency_list<OutEdgeListS, VertexListS, DirectedS, VertexProperty, EdgeProperty, GraphProperty, EdgeListS>, T Bundle::*>::const_type get(T Bundle::* p, adjacency_list<OutEdgeListS, VertexListS, DirectedS, VertexProperty, EdgeProperty, GraphProperty, EdgeListS> const & g) { typedef typename property_map<adjacency_list<OutEdgeListS, VertexListS, DirectedS, VertexProperty, EdgeProperty, GraphProperty, EdgeListS>, T Bundle::*>::const_type result_type; return result_type(&g, p); } template<typename OutEdgeListS, typename VertexListS, typename DirectedS, typename VertexProperty, typename EdgeProperty, typename GraphProperty, typename EdgeListS, typename T, typename Bundle, typename Key> inline T get(T Bundle::* p, adjacency_list<OutEdgeListS, VertexListS, DirectedS, VertexProperty, EdgeProperty, GraphProperty, EdgeListS> const & g, const Key& key) { return get(get(p, g), key); } template<typename OutEdgeListS, typename VertexListS, typename DirectedS, typename VertexProperty, typename EdgeProperty, typename GraphProperty, typename EdgeListS, typename T, typename Bundle, typename Key> inline void put(T Bundle::* p, adjacency_list<OutEdgeListS, VertexListS, DirectedS, VertexProperty, EdgeProperty, GraphProperty, EdgeListS>& g, const Key& key, const T& value) { put(get(p, g), key, value); } #endif " What is the replacement to this "get" accessor? Regards, Fabien

2 4

unable to merge trunk
by Oliver Kowalke 17 Sep '12

17 Sep '12

could I get a little bit more time to merge trunk into release? currently subversion fails with strange errors: svn merge ../../../boost-trunk/libs/context svn: error executing »xxdiff-subversion«: return value: 255, parameter: in directory ».«, Basename: doc/.svn/tmp/svn-z6MhPR /tmp/svn-1pKQPw doc/.svn/tmp/svn-wdZ3Xa svn: error reading answer of REPORT request from hdd Oliver

2 2

[Review.Contract] Vicente's review
by Vicente J. Botet Escriba 17 Sep '12

17 Sep '12

Hi, here is my short review. My vote is YES subject to these condition. * Removal of the Concepts part. The use of Boost.ConceptCheck to emulate C++ concepts proposal is in my opinion erroneous. Boost.Concept.Check is used to assert the actual parameter satisfy statically the concept conditions, while if I'm not wrong the C++ Concepts proposal use the requires clause to state the conditions of a possible instantiations. Using the same grammar with different semantics is confusing. In a last resort, if this feature is preserved, the requires keyword must be changed by another one. * static assertions are removed from the pre/post conditions. They can be moved to a specific "static assertions" section at the same level than the requires clause. This section could also include the concept check included now in the requires clause. * The library extends the EDSL to use directly C++11 features, in particular move semantics. Now that since the C++11 standard is released, more and more people are using C++11 specific features. I, in particular, will not use Contract if I can not make use of C++11 features provided by the compiler. * The contract broken handlers are noexcept, so that adding contracts don't change the original prototype. === STANDARD REVIEW QUESTIONS === * What is your evaluation of the design? While Lorenzo has show that using the preprocessor we can define a EDSL that is close to the native syntax (besides the parentheses stuff), the resulting interface is *closed* and interacts badly with c++ features not taken in account by the EDSL. I'm guessing that the user can not extend this EDSL without modifying the library. This is also the case of other libraries that make use of the pre-procesor to define a EDSL as Boost.Parameters or Toward Boost.Generics. It will be great if the user can extend the EDSL, but I suppose this could be very hard, if not impossible. I understand that Lorenzo is trying to reduce the preprocessor time using whatever is needed, but making the interface more complex would not help to improve the usability. I'm not sure the _TPL macros are really needed and whether the resulting code could perform better or not. * What is your evaluation of the implementation? I've not look inside. * What is your evaluation of the documentation? Very good. I would appreciate if the documentation includes a sections showing what is behind the scenes, what is generated by these macros. It would be great if you add a section/table with all the limitations, as e.g. these ones * Function and array types cannot be directly used as function parameter types within the contract macros ... * Each function parameter must always specify both its type and its name (parameter names can instead by omitted in usual C++ declarations). * All tokens must be specified in the fixed order listed in theGrammar section (it is not possible to specify postconditions before preconditions,|volatile| before|const| for member functions, etc). * Unfortunately, this library does not allow to specify contracts for unions. * Unfortunately, when member initializers are specified, the constructor body must be defined together with its declaration and contract * What is your evaluation of the potential usefulness of the library? I don't think the library could be used in a industrial context. The domain of this preprocessor EDSL is too large (C++ declarations + contracts + named parameters + concepts) and we will need to expand it yet to be useful (c++11, compiler specifics, ...). While the syntax is quite close to C++ syntax the library intends to emulate, the compiler errors will be quite unreadables. * Did you try to use the library? With what compiler? Did you have any problems? No. * How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? I have not do a in-depth study. I has been concentrated inspecting the usability of the library and trying to identify the limitations it could introduce. * Are you knowledgeable about the problem domain? Yes, from a theoretical point of view. I have never used contract programming in real world projects. Best, Vicente

4 12

[Review:Contract]
by Roland Bock 17 Sep '12

17 Sep '12

Hi, first of all, YES, the library should be included in BOOST, in my opinion. In addition: * What is your evaluation of the design? Very cool. Looks like a 1:1 translations from some good algorithm books into code :-) * What is your evaluation of the implementation? I spent some time browsing through the macro code hoping it would help me to solve a problem of my own which looked similar (turned out it wasn't). Never being a fan of too much macro code, I have to say that this is very nicely written! My only concerns: - It seems to me that the implementation is spread over more files than necessary. It made following the call stack a bit tiresome. - I a bit torn between a) Steven's comment who would like to see CONTRACT_OLDOF being replaced by the would-be keyword in a possible future standard b) boost macros being clearly visible as such, leaving translation to future standard keywords to the user of the library, e.g. #define foreach BOOST_FOREACH I tend towards b). * What is your evaluation of the documentation? Excellent! * What is your evaluation of the potential usefulness of the library? It is a very good proof of concept and hopefully the basis for continued discussions about including contracts into the C++ language. Due to a lack of formal contracts in much of day to day programming and the enormous compile time overhead, I don't see the library being used all over the place anytime soon, but I expect it to be used in generic algorithms, helping both developers and library users. * Did you try to use the library? With what compiler? Did you have any problems? Sadly: No. Did not find the time. * How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? I spent a few hours with the code, maybe two hours with the documentation and I followed some of the discussions during the review period. * Are you knowledgeable about the problem domain? I would not call myself an expert, but I know enough to say: I'd really like to have Boost.Contract available the next time I write a mission-critical function/class/library! Best regards, Roland PS: Sorry for being late. I'm hoping for lenience since the review period was announced a bit late as well :-)

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What Should we do About Boost.Test?
by Dave Abrahams 17 Sep '12

17 Sep '12

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

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[Review:Contract] Boost.Contract Library is Accepted
by Dave Abrahams 17 Sep '12

17 Sep '12

Lorenzo Caminiti's Boost.Contract Library is hereby accepted into Boost. I will be brief but that should in no way be construed as a lack of enthusiasm. Reviewing the review commentary was a genuine pleasure. Anyone interested in this domain could learn a lot by going through the threads the way I did. There were five "yes" votes, one of which was very late (but I'm counting it), and one of which was conditional, and one "no" vote. I am accepting the library unconditionally because of Lorenzo's demonstrated responsiveness to issues. He gave thoughtful responses to the review comments and entered every issue raised that remained open into a bug database (http://sourceforge.net/apps/trac/contractpp/report/3) Congratulations, Lorenzo! -- Dave Abrahams BoostPro Computing Software Development Training http://www.boostpro.com Clang/LLVM/EDG Compilers C++ Boost

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boost::asio::detail::win_iocp_io_service
by xakepp35 17 Sep '12

17 Sep '12

good time of day. i need to extend some basic boost functionality and performance by 1) variable timeouts in poll/run 2) replacing GetQueuedCompletionStatus with GetQueuedCompletionStatusEx and parallelized vectored i/o handling with single kernel/user transition so how can i replace win_iocp_io_service with my own implementation without modifying it's code inside "io_service.hpp"? there are HARD-CODED strings inside "io_service.hpp" like namespace detail { typedef win_iocp_io_service io_service_impl; } which better be something like user #define or template with default argument (like allocator) how do you suppose user may provide it's own implementation? how can i use my_iocp_io_service, declared and implemented within my executable's sources? -- View this message in context: http://boost.2283326.n4.nabble.com/boost-asio-detail-win-iocp-io-service-tp… Sent from the Boost - Dev mailing list archive at Nabble.com.

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[review][coroutine] A Late Review
by Stewart, Robert 17 Sep '12

17 Sep '12

Coroutine should be accepted into Boost conditionally. My hesitation comes from the seemingly significant design and interface changes occurring during the review. I'm unsure how the current state compares to the library I reviewed. This leaves me wondering what is being accepted. I don't think the functionality of the library is changing, so I'm confident in accepting it on that basis. However, I think that a mini-review is needed to verify the finished design and documentation before final acceptance. ***** What is your evaluation of the design? I dislike the namespace. "coro" is meaningless and awkward. The namespace name should be "coroutines" (since there is a class named "coroutine", it must be plural). What users may choose as an alias is another matter. I wonder whether assertions can be added to flag calls of operator() from within a coroutine or generator. I know that's undefined behavior, but an assertion will catch the mistake in non-optimized builds. ***** What is your evaluation of the implementation? The source has major whitespace issues. It looks like a botched tab-to-spaces conversion. The move assignment operators do a self-assignment check. That is a "performance bug", as Howard Hinnant puts it. There are no comments in the code. This means Oliver's own maintenance will be harder, but it particularly means that it will be harder for anyone else to pick up the library's maintenance to help or replace Oliver in the future. The code looks well factored, though I certainly didn't spend a long time studying it. ***** What is your evaluation of the documentation? There is no Motivation section. The documentation must catch the attention of the reader right on the first page. Why should anyone care about this library? What can it do for them? Why should anyone spend time reading the rest of the documentation? Overall, the documentation is a good introduction to the library. The examples are appropriate for tutorial purposes, but there is a complete lack of non-trivial examples to illustrate how the library can be employed. What can one do with this library that isn't possible otherwise? What is better, according to any number of criteria like less code, faster, etc., using this library? How much of the interface remains what was designed by Giovanni Piero Deretta? Given all of the changes during the review, I wonder how much remains. The "Executing a coroutine" section of coroutine.html could do with a sentence about the coroutine-function's signature as, say, a new, third sentence in the first paragraph: "The coroutine-function can take arguments and return values as discussed in the next section." The "Exceptions in coroutine-function" section of coroutine.html, and the corresponding section of generator.html, suggests that exceptions must be thrown using Boost.Exception. Is that the intent? If so, you need to make that point clear. I suppose that isn't true in C++11. Also, what is the namespace of forced_unwind? This section is the first mention of it, so one is left to wonder if it belongs to the library or not. The "FPU preserving" sections of coroutine.html and generator.html imply that the library allows to prevent preserving the FPU registers, but gives no information about how that is done or where to read more about it. Also, the note, in those sections, references "ABIs", but gives no references and fails to specify which ABIs are meant. The coroutine and generator synopses, in coroutine/coroutine.html and generator/generator.html, are confusing. The definition of self_t refers to undefined types T and R. The synopsis of coroutine suggests that the type is not copyable Some detailed comments are at the end of this message. ***** What is your evaluation of the potential usefulness of the library? I think this library will be extremely useful. I think it could have profound implications for the design of libraries that rely on multiple threads today. Indeed, there is a use case in some current code in one of our applications that, I think, would be simplified yet improved by using this library. - Did you try to use the library? With what compiler? Did you have any problems? Unfortunately, and despite the lateness of my review, I've had no time to try it. - How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? I spent several hours reading the documentation, and a fraction of that looking over the code. ***** Are you knowledgeable about the problem domain? No. ___________________ Documentation Comments ________________ coroutine/coroutine.html The illustration of make_coroutine() is accompanied by no description, so f() should be omitted. It adds nothing one cannot infer from the signature and raises questions about what c and, in turn, f() actually does. In the first warning, s/coroutine/a coroutine/. In the second, s/::FlsAlloc(), ::FlsFree()/::FlsAlloc() and ::FlsFree()/. s/stack-allocator/stack allocator/ Odd internal spacing for parentheses: one space after the open parenthesis, and no space before the close parenthesis. s/operator()()/operator()/ s/flags, and stack and instruction/flags, stack, and instruction/ s/value of local variable is preserved/value of local variable i is preserved/ "yield was called so we returned" is confusing. The coroutine hasn't been called by that point. That comment should probably be, "while the coroutine hasn't returned" (or "finished"). In Transfer of data, the last sentence of the second paragraph (after the note) is rather confusing and includes a grammatical error. I suggest this instead: "The arguments passed to coroutine<>::operator(), in one coroutine, are passed to coroutine<>::self_t::yield() in the other coroutine, except for the first invocation of coroutine<>::operator(), which passes them to the coroutine- function, instead." The example in Transfer of data could use with a few more comments. Specifically, "int x = c(7)" could use the comment, "x is 7 because c(7) passes 7 to fn, where self.yield(i) passes i == 7 back", and "x = c(10)" could use the comment, "x is 10 because c(10) causes "self.yield(i)" to return 10 in fn(), so fn() returns j == 10". While you're at it, s/j == 10 because c( 10) in main()/j == 10 because of c(10) in main()/. The coroutine-function with multiple arguments example deserves some comments explaining why yield() gets one int argument and returns a two-int tuple and why the function returns one int, to tie those aspects into the Signature template argument. The Exit a coroutine-function section discusses yield_break(), but the example calls yield_return(). In the Important note within Exit a coroutine-function, s/complete (can not resumed/complete and cannot be resumed/. In Stack unwinding, s/(stack is unwound by default)/(the default)/. In FPU preserving's note, s/ABIs the/ABIs, the/. ________________ coroutine/coroutine/coroutine.html In the Effects of the template constructor, s/stack before destructing it/stack before releasing it/. In the Effects of the function call operator, the wording can be improved: "Invokes the coroutine-function with the supplied arguments, returning the argument passed to self_t::yield()." Likewise, the Throws clause: "Any exception emitted by the coroutine-function or coroutine_terminated if self_t::yield_break() is called." The Effects of self_t::yield() can be improved: "Returns execution control to the calling context, arranging for the calling context's operator() to return r." (You need to make the argument list "(R r)" for that description.) Next, yield() needs a "Returns" clause: "Returns: " Arguments passed to the calling context's operator()." Change the Effects clause for yield_break() to: "Marks the coroutine complete and returns execution control back to the calling coroutine in such a way as to cause the calling coroutine's operator() to emit a coroutine_terminated exception." ______________ generator.html s/yielding a values/yielding values/ s/and can be returned/, so they can be returned/ make_generator() is not introduced. The illustration of make_generator() is accompanied by no description, so f() should be omitted. It adds nothing one cannot infer from the signature and raises questions about what c and, in turn, f() actually does. (If you choose to keep it, perhaps "g" is a better identifier for a generator.) In the second note, s/::FlsAlloc(), ::FlsFree()/::FlsAlloc() and ::FlsFree()/. Also, that same information is marked as a warning for coroutine. In the warning, s/If generator/If a generator/. There are no comments in most of the examples on this page. The fifth paragraph of Executing a generator needs to be rewritten to fix mistakes and improve clarity: "A generator is usually called inside a loop. The generator- function calls generator<>::self_t::yield() to produce a value. When the generator is called a second or subsequent time, the generator-function resumes execution after the yield() call. If a generator-function must be called no more, it can call generator<>::self_t::yield_break()." The sixth paragraph also needs to be rewritten: "The generator-function is invoked the first time from the generator's constructor. generator<>::operator() can be called while the generator is valid (while generator<>::operator unspecified_bool_type() returns true). When the generator-function cannot return more values, it can return a value or call generator<>::self_t::yield_break(). The latter returns execution control back to the caller and marks the generator complete. Note that generator<>::operator() does not thrown an exception, unlike a coroutine." (It isn't clear whether returning from a generator-function marks a generator complete.) In the last Executing a generator example, the "yield was called so we returned" comment within main() is a bit unclear. I suggest, "calls fn()" on g's construction and "fn()called self.yield(), so control returned here" on "while (g)". In the Important note within Exit a generator-function, s/complete (can not resumed/complete and cannot be resumed/. _______________ generator/generator.html The Effects clause of operator() would be better separated into an Effects and a Return clause: "Effects: " Invokes the generator-function." "Returns: " The value passed to self_t::yield() by the generator-function." Likewise, for self_t::yield(): "Effects: " Returns execution control to the calling context such that generator<>::operator() returns r in the calling context. "Returns: " The arguments passed to generator<>::operator() in the " calling context." The Effects clause for self_t::yield_break() is incorrect. I suggest the following: "Marks the generator complete and returns execution control to the calling context." _____ Rob Stewart robert.stewart(a)sig.com Software Engineer using std::disclaimer; Dev Tools & Components Susquehanna International Group, LLP http://www.sig.com ________________________________ IMPORTANT: The information contained in this email and/or its attachments is confidential. If you are not the intended recipient, please notify the sender immediately by reply and immediately delete this message and all its attachments. Any review, use, reproduction, disclosure or dissemination of this message or any attachment by an unintended recipient is strictly prohibited. Neither this message nor any attachment is intended as or should be construed as an offer, solicitation or recommendation to buy or sell any security or other financial instrument. Neither the sender, his or her employer nor any of their respective affiliates makes any warranties as to the completeness or accuracy of any of the information contained herein or that this message or any of its attachments is free of viruses.

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Proposed new RAII Library
by Andrew Sandoval 17 Sep '12

17 Sep '12

I'd like to propose a new Boost library for RAII wrapper classes that I think could be standardized to help promote the use of RAII. Though shared_ptr, scoped_ptr, etc. greatly enhance the use of RAII, I propose two additional classes. The first of these is RAIIFunction (I'm open to other names and coding conventions). This one is very simple, but powerful. It's a small wrapper (using composition) around std::tr1::function, that simply calls the function on scope-exit, in the normal case. Unlike Boost.ScopeExit, it uses no macros. Anything that can be assigned to a std::tr1::function<AnyType> taking no parameters will work with it, so lambdas are perfect -- and allow for all of the associated benefits like capturing variables by reference, etc. It also works with std::tr1::bind / boost::bind, with no placeholders. // // RAIIFunction<> Written by Andrew L. Sandoval 2011/2012 // Include guard here #include <functional> // // An RAII class that works with std::tr1::bind and lambdas // NOTE: making a const RAIIFunction prevents the use of Invoke() // and Cancel() and operator=(fn) which is often appropriate // NOTE: m_func copies the original function object, so that const and // non-const refs can be passed in, etc. template <typename TRet> class RAIIFunction { private: std::tr1::function<TRet ()> m_func; bool m_bInvoke; RAIIFunction(); RAIIFunction(const RAIIFunction &); void operator=(const RAIIFunction &); public: RAIIFunction(const std::tr1::function<TRet ()> &fn) : m_func(fn), m_bInvoke(true) { } void operator=(const std::tr1::function<TRet ()> &fn) { if(m_bInvoke) { m_func(); } m_bInvoke = true; m_func = fn; } ~RAIIFunction() { if(m_bInvoke) { m_func(); } } void Cancel() { m_bInvoke = false; } TRet Invoke(bool bRelease = false) { m_bInvoke = !bRelease; return m_func(); } }; Examples: const RAIIFunction<void> closeDB = ([pDB]() { if(pDB) { sqlite3_close(pDB); } }); // // while example... bool bContinue = true; RECORD record = { }; while(bContinue) { // Ensure that no matter how the loop wraps (continue or fall-through) the next // record is grabbed or the loop terminates... const RAIIFunction<void> loopAdvance = ([&bContinue]() { bContinue = SomeCallThatGetsAnotherRecord(record); }); // A bunch of record processing here ... } // // A convoluted example that shows assignment, etc. RAIIFunction<int> mb = std::tr1::bind(MessageBoxW, HWND_TOP, L"Present pop-up prompt again?", L"Test", MB_TOPMOST|MB_YESNO); int iMB = mb.Invoke(true); if(IDYES != iMB) { mb = ([]() ->int { dprintf("Printing what the user didn't wanted popped up" " on scope-exit...\n"); return 0; }); -- The other one I call just RAIIWrapper, and it works with static deleter functions taking a single argument of the type being delete. Since it includes a lot more code (much of which could probably be replaced with type_traits code), I'll just show examples of usage below to gauge interest. I first used an earlier version of this in an environment where the standard function required a goto ErrorExit (like Microsoft example driver code in the WDK) to clean-up all of the resources. The original concern was that the c++ class would bloat the deliverable size. This class proved to be as tight as the goto equivalent. It uses one macro that I'll include below. The class takes 3 template parameters: 1) The type of the deleter function, 2) the deleter function, and 3) a no-delete value that defaults to NULL. // // Simplify usage with a macro: #define RAIIDeleter(deleterFunction) decltype(&deleterFunction), deleterFunction // Example: const RAIIWrapper<RAIIDeleter(CloseHandle), INVALID_HANDLE_VALUE> hFile = CreateFile(pwzFileName, GENERIC_WRITE, FILE_SHARE_WRITE, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL); if(!hFile.IsValid()) { // handle error... } // Similar but using the default no-delete value (NULL): const RAIIWrapper<RAIIDeleter(CloseHandle)> hEvent = CreateEvent(NULL, FALSE, FALSE, NULL); -- I've found that using RAII consistently can dramatically improve code quality. It forces the coder to think about resource lifetime at inception rather than at exit points, etc. Much of what I've shown above can be done with scoped_ptr or shared_ptr, but these specialized classes put the focus on RAII and resource management. Please let me know your thoughts. I'd love to see this become part of Boost, and hopefully eventually part of the C++ standard library. Thank You, Andrew Sandoval

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[rational] optional over/underflow checking
by Dan Searles 17 Sep '12

17 Sep '12

>> https://svn.boost.org/svn/boost/sandbox/rational Sandbox now includes the test driver. All the updates are in the single rational header file, so this is a relatively small update. Rational.h, however, has had small updates before. This update centers on adding an optional over/underflow check, that would generate an exception if the result of an operation could not be represented with full numeric precision. Seeking comments on the update and any steps/requirements needed to get the update accepted for release. BTW, are there any status updates on the unlimited precision numeric class effort? Thanks, Dan Searles

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Re: [boost] [result_of] Usage guidelines
by Andrey Semashev 17 Sep '12

17 Sep '12

Ok, here is my second take on this. I've attached a patch with my changes. 1. I moved the guidelines to a separate section in order not to clutter the formal result_of description. 2. I seperately outlined the C++11 and C++03 recommendations. 3. I left the result_of examples. I think they illustrate the result_of usage quite well, but I'll be happy if someone comes up with something better. 4. I rephrased some of the wording about result<> usage, in response to Jeffrey's reply. Comments are welcome.

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[ASIO] async SSL operations unnecessary serialized?
by Michał Madziar 16 Sep '12

16 Sep '12

Hello all. It looks like all openssl_operation handlers are synchronized on io_service allowing only one connection to be processed at the a time. As I understand this orginated from the time when libopenSSL didn't support multi-threaded applications, but it slows down everything a lot. Adding locking function, and getting rid of strand_->wrap in lines 320, 385 in file boost/asio/ssl/detail/openssl_operation.hpp allows SSL connections to be used in multiple threads simultaneously solving the problem. Or do I miss something? I've attached simple line-based echo server which demonstrates the problem: openssl s_client -connect localhost:10001 #x 2 telnet localhost 10000 #x 2 After sending something in each connection TCP and one SSL work in parallel, second SSL waits with receiving until first one finishes it's write. After patching all connections work in parallel. -- Pozdrawiam Michał 'michoo' Madziar

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{Review] Coroutine reviewstarts today, September 3rd
by Hartmut Kaiser 16 Sep '12

16 Sep '12

Hi all, The review of Oliver Kowalke's Boost.Coroutine library starts today, September 3rd 2012, and will end on September 12th. I really hope to see your vote and your participation in the discussions on the Boost mailing lists! ----------------------------------------------------- About the library: Boost.Coroutine provides templates for generalized subroutines (coroutines) which allow multiple entry points for suspending and resuming execution at certain locations. It preserves local state/data and allows re-entering subroutines more than once (useful if state must be kept across function calls). Coroutines can be viewed as a language-level construct providing a special kind of control flow. You can download the library and the view documentation here: docs: http://ok73.ok.funpic.de/boost/libs/coroutine/doc/html/ src: http://ok73.ok.funpic.de/boost.coroutine.zip --------------------------------------------------- Please always state in your review, whether you think the library should be accepted as a Boost library! Additionally please consider giving feedback on the following general topics: - What is your evaluation of the design? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - What is your evaluation of the potential usefulness of the library? - Did you try to use the library? With what compiler? Did you have any problems? - How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? - Are you knowledgeable about the problem domain? Regards Hartmut Review Manager

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[result_of] Make result_of doc separate from utility.htm
by Michel Morin 15 Sep '12

15 Sep '12

The documentation of result_of is contained in monolithic utility documentation: http://www.boost.org/libs/utility/utility.htm But I think result_of is worth having its own (i.e. separate) documentation. Comments? Regards, Michel

1 0

[ublas] Trunk testing broken
by Belcourt, Kenneth 15 Sep '12

15 Sep '12

Someone forgot to commit a file? error: Unable to find file or target named error: 'test_ticket7296.cpp' error: referred to from project at error: '../libs/numeric/ublas/test'

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[nowide] Library looks for a review manager
by Artyom Beilis 15 Sep '12

15 Sep '12

Hello, The project Boost.Nowide searches a review manager: What is Boost.Nowide: --------------------- Boost.Nowide is a library implemented by Artyom Beilis that make cross platform Unicode aware programming easier. The library 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. Documentation: http://cppcms.com/files/nowide/html/ Downloads: http://cppcms.com/files/nowide/ Artyom Beilis -------------- CppCMS - C++ Web Framework: http://cppcms.com/ CppDB - C++ SQL Connectivity: http://cppcms.com/sql/cppdb/

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[system] Patches to apply when BOOST_ERROR_CODE_HEADER_ONLY or BOOST_NO_EXCEPTIONS are defined
by Vicente J. Botet Escriba 15 Sep '12

15 Sep '12

Hi, I have added some simple patches for these two tickets https://svn.boost.org/trac/boost/ticket/7347:duplicate symbol while BOOST_ERROR_CODE_HEADER_ONLY is defined https://svn.boost.org/trac/boost/ticket/7149:system failed to compile with BOOST_NO_EXCEPTIONS defined when -fno-exceptions is NOT used Could I apply them to trunk? Best, Vicente

1 0

[system] Patches to apply when BOOST_ERROR_CODE_HEADER_ONLY or BOOST_NO_EXCEPTIONS are defined
by Vicente J. Botet Escriba 15 Sep '12

15 Sep '12

Hi, I have added some simple patches for these two tickets https://svn.boost.org/trac/boost/ticket/7347:duplicate symbol while BOOST_ERROR_CODE_HEADER_ONLY is defined https://svn.boost.org/trac/boost/ticket/7149:system failed to compile with BOOST_NO_EXCEPTIONS defined when -fno-exceptions is NOT used Could I apply them to trunk? Best, Vicente

1 0

[Review:Contract] Very late review
by John Bytheway 15 Sep '12

15 Sep '12

I was out of touch for most of the review period, but I wanted to submit a review of Contract anyway. The review manager is of course welcome to ignore my comments or otherwise give them short shrift as he sees fit as a consequence of this delay, but I hope Lorenzo will welcome more feedback :). Firstly, I would like to add my voice to those who are congratulating Lorenzo on the quite remarkable feat this library represents. It has obviously required extensive and careful thought and effort to reach this state. It is primarily because of this evident conscientiousness that I will vote YES, I think the library should be accepted into Boost. I concur with previous reviewers that it is unlikely to suit industrial use, but it is an important experiment, and one which will benefit from the additional exposure granted by inclusion in Boost. My review follows. Problems using the library ========================== I only experimented very briefly, but found one problem (which may well be a clang bug, but you should probably investigate). The following program I tried works with gcc-4.7.1 but not with clang r163674 (both in C++11 mode): #include <contract.hpp> CONTRACT_FUNCTION( int (postinc) ( (int&) value ) precondition( value < std::numeric_limits<int>::max() ) ) { return value++; } int main() { int i = std::numeric_limits<int>::max(); postinc(i); return 0; } The first few errors with clang all look like: In file included from contract-failure-test.cpp:1: In file included from .../contractpp_0_4_1/include/contract.hpp:14: .../contractpp_0_4_1/include/contract/broken.hpp:359:7: error: call to object of type 'thread_variable<broken_contract_handler>' is ambiguous { aux::broken_handlers<>::precondition(context); } ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .../contractpp_0_4_1/include/contract/aux_/thread_variable.hpp:42:5: note: conversion candidate of type 'void (*)(const contract::from &)' operator T() const { // Sync so must return object copy (by value). ^ .../contractpp_0_4_1/include/contract/aux_/thread_variable.hpp:49:5: note: conversion candidate of type 'void (*)(const contract::from &)' operator T() const volatile { // Sync so must return object copy (by value). ^ Minor issues in the docs ======================== (I'm not mentioning issues already raised in another review) Tutorial -------- - I think it's slightly unfortunate that your example function name ("postinc") shares a four-character prefix with "postcondition". This threw me a couple of times when I was reading too fast. - "specify both its type and its name (parameter names can instead by omitted in usual C++ declarations)" -- I found this phrasing confusing. I think you were planning to remove this constraint anyway so it doesn't matter, but FWIW I would recommend something like "specify both its type and its name (unlike conventional C++ declarations, where parameter names may by omitted)". - "and assigning it to the return keyword" -- also confusing. Perhaps "and assigning to it from the return keyword" - "destructors cannot specify neither preconditions nor postconditions" -- double negative; should be "destructors can specify neither preconditions nor postconditions" - The whole "Forward Declarations and Body Definitions" section is a bit odd. The code example doesn't seem to match up with the text. For example, you say "less and natural::get are defined together with their declarations", but in fact less is forward-declared at the top of the file with no definition. Advanced topics --------------- - "the postcondition result = n * factorial(n - 1) has factorial computation complexity" -- this is not true; the factorial function as defined here has linear complexity, not factorial complexity. (If it were using arbitrary precision integers it would be something like O(n^2 log(n)^2) but still certainly polynomial, not super-exponential!) - "preconditions cannot only be weakened" -- again s/cannot/can/ Named parameters ---------------- - By using "requires" here in the pseudocode example with a different meaning from the rest of the library you are further muddying the waters. If you change the "requires" keyword that is used by the library to something else (as discussed below) then this will no longer be a problem. - In footnote 61 (Boost.Parameter bug) could you please link to the bug so that future readers will know when it is fixed. Doxygen ------- You've mentioned a few times the the Doxygen preprocessor can't cope with your preprocessor metaprogramming. Have you submitted bugs to Doxygen? Do you know how receptive they are to improving their preprocessor conformance? This library might be a compelling incentive for them to do so. Design issues ============= The vast majority of the design is clearly well-grounded in existing practice and practicality. Nevertheless, I have a few issues to raise. Concepts -------- I agree with the earlier thread that you should not use the term "requires" in the way you currently are, because it has a different meaning in the Concepts proposal. Alternatives as discussed there such as "check" would be an improvement. Contract broken message ----------------------- The above example program generates the following broken contract report: precondition number 1 "value < std::numeric_limits<int>::max()" failed: file "contract-failure-test.cpp", line 8 I would like my editor (Vim, though this comment applies equally to others) to automatically take me to the line where the failure occurred. I could of course configure it appropriately, but it might make your users lives easier if you used a standard error format which editors will recognize by default, such as: contract-failure-test.cpp:8:precondition number 1 "value < std::numeric_limits<int>::max()" failed Furthermore, I suspect that it is quite likely that these contract broken messages might occur at odd times, such as when the program is in the midst of printing something else to stdout/stderr, so it might be a good idea to prefix all your messages with a newline. Best of all, perhaps, would be to provide a customization point for the message format (which doesn't entail changing all five broken handlers). This would allow me to make these changes to the messages without disturbing other users. Contract broken handlers ------------------------ Based on your example, I presume that if I install a custom handler for broken contracts, and that handler returns without throwing, then execution will simply continue merrily without regard to the detected contract violation. I can see why you might feel the need to provide such functionality ... but my first instinct is that if a custom handler returns the library should take over and call std::terminate anyway (this is similar to the way that a constructor function-try block will not allow you to swallow an exception thrown by a base or member constructor). But I don't feel strongly about this. At the least, you should document this turn of events more clearly; I only figured it out from the very last footnote in advanced topics. Configuration macros -------------------- This is my biggest concern with the library at present. You provide the various macros for configuration (CONTRACT_CONFIG_NO_PRECONDITIONS etc. as in <contract/config.hpp>). However, they are all essentially global constants. Suppose I am writing an application that depends on a library, and they both use contracts in their declarations. I would like to have only preconditions active for the library, but all contracts checked for the application. There is no way to achieve this. CONTRACT_CONFIG_DO_NOT_SUBCONTRACT_PRECONDITIONS causes a similar but different problem. If the library subcontracts preconditions then I can't disable them for my application. I think you need to provide a means to turn the various features on and off on a per-project basis. As one suggestion, suppose that you took extra arguments to your macros, so that the above example became: CONTRACT_FUNCTION( MYAPP_NO_PRECONDITIONS, MYAPP_NO_POSTCONDITIONS, int (postinc) ( (int&) value ) precondition( value < std::numeric_limits<int>::max() ) ) { return value++; } and then I define a wrapper macro for my app which substitutes these arguments for me, and therefore the example becomes: MYAPP_CONTRACT_FUNCTION( int (postinc) ( (int&) value ) precondition( value < std::numeric_limits<int>::max() ) ) { return value++; } Or perhaps rather than many variables it would be better to have a single MYAPP_CONTRACT_CONFIG value which contained all of them (as a preprocessor tuple, say) which was passed in similarly. Anyway, I'm sure you can think of something appropriate. Philosophical issues ==================== Finally, I'd like to go off on a bit of a tangent and talk about a philosophical problem with the design. It has been touched on by other reviewers but I'd like to go into more detail. Your library design is very syntactically invasive. As the docs indicate, this makes it unfamiliar, slow to compile, and potentially difficult to debug. But none of these is the worst problem. To worst problem is that only one library can do this. You've already seen this, and done your best to integrate the other Boost libraries that have similar requirements (Parameter and Concept) but this approach doesn't scale. I'm sure at least one of the many reflection libraries proposed to Boost does something similar. Will you integrate that too? What about non-Boost libraries. The only scalable solution is to write a framework for customized definitions. You've mentioned the possibility of using the knowledge your alternate syntax has to expose extra data (e.g. function access level) at preprocessor time. But that's not enough. It would have to allow other library authors to inject code into definitions in the way Contract or Parameter needs to; even provide whole new definition syntaxes as Property does. Given such a framework, each other library (Contract, Parameter, a reflection library, and whatever else) would be written using the framework. It should then be possible to use whichever a user desires, at the same time, for the same declaration, without those libraries having any knowledge of each other. Such a framework would be akin to the language customization features that some other languages have (and which have also been mentioned in other threads of this review). To be clear, I am certainly not demanding, nor even proposing, that you implement such a framework. I think it would be extremely difficult -- more trouble than it's worth. It would also be very dangerous (for all the same reasons that it is dangerous to be able to customize the language on the fly). So long as Contract remains a primarily experimental library the current design is perfectly adequate. I just think that this direction is the logical conclusion of your efforts, and wanted to bring it to your attention (though you've probably already had similar thoughts). Standard review questions ========================= * What is your evaluation of the design? Barring issues mentioned above, it is an excellent attempt to solve a very difficult problem. * What is your evaluation of the implementation? I did not examine it. * What is your evaluation of the documentation? I did not read the reference; the rest was very good, with minor nits as above. * What is your evaluation of the potential usefulness of the library? It has significant potential for use in small projects, to spread the idea of contract programming, serve as a proof of concept and influence future standardisation efforts. It is unlikely to see use in large scale industrial programming. * Did you try to use the library? With what compiler? Did you have any problems? Very briefly, with compilers and problems mentioned above. * How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? I spent three evenings reading the docs and writing my review, and have been following the development of the library on the list since its first appearance. I would have liked to do more experiments, but my review was already late enough! * Are you knowledgeable about the problem domain? Not to any notable degree. Congratulations again to Lorenzo on achieving something I would have thought impossible; with luck it might inspire me to actually try contract programming. John Bytheway

2 1

[preprocessor] automatic recursion curiosity
by Lorenzo Caminiti 14 Sep '12

14 Sep '12

Hello all, I have a curiosity about an implementation detail of Boost.Preprocessor: How does the lib implement Automatic Recursion? >From the docs under Topic > Reentrancy > Automatic Recursion: http://www.boost.org/doc/libs/1_51_0/libs/preprocessor/doc/index.html `` Using automatic recursion to reenter various sets of macros is obviously much simpler. It completely hides the underlying implementation details. So, if it is so much easier to use, why do the state parameters still exist? The reason is simple as well. When state parameters are used, the state is known at all times. This is not the case when automatic recursion is used. The automatic recursion mechanism has to deduce the state at each point that it is used. This implies a cost in macro complexity that in some situations--notably at deep macro depths--will slow some preprocessors to a crawl. '' I have not looked at the source code and I'm looking for the glory details. However, I'd like to understand at a high level how Boost.Preprocessor is able to implement Automatic Recursion behind the scene (it just bothers me not being able to imagine how this is actually done and why it is expensive on some preprocessors). Can anyone provide a quick explanation or point me to some email thread / docs that explain that? Thanks a lot! --Lorenzo

2 1

[Review.Coroutine] Vicente's review
by Vicente J. Botet Escriba 13 Sep '12

13 Sep '12

Hi, I understand that Oliver is busy as all of us and that it is better to provide first the minimal and well designed scope he is confident with. I expect however that Oliver will add soon symmetric coroutines based on the work done by Giovanni in a near future. - What is your evaluation of the design? I have some suggestions about changing the interface, but I'm not sure all of them could be implemented in an efficient way. * The use of thecoro_t::self_t & self parameter makes too much noise. This parameter must be forwarded to any function that could yield the coroutine. An alternative design using a thread specific pointer could allow to access the current coroutine int f20() { typedef this_coroutine<int(void)> this_coro; this_coro::yield(5); } Is the rationale for using self_t to get better performances? Maybe both interfaces could be provided. * There is an asymmetry between the value returned the last time and the others. self.yield( i); // OTHERS return i; // LAST This asymmetry forces the user to manage the last return in a specific case, changing the readability of the code. I would prefer coroutine function returns void. voidfn( coro_t::self_t & self) { self.yield(1); self.yield(2); } * If this is not adopted, the implementation should check at compile time that the return type of the coroutine function is the one of the signature. * The access to the actual coroutine parameters is asymmetric, letting access to old actual parameters that can point to objects that have already been destroyed. Maybe the self_t object could take care of this (or this_coroutine). We can use a get<> function to give access to the actual parameters. int f20(coro_t::self_t & self) { self.yield(2*self.get<0>()); } int f20() { typedef this_coroutine<int(int)> this_coro; this_coro::yield(2*this_coro::get<0>()); } Or even use some kind of bind parameter int f20(coro_t::self_t & self) { int i; int j; self::bind(i, j); self.yield( i + j ); } int f20() { int i; int j; typedef this_coroutine<int(int)> this_coro; this_coro::bind(i, j); this_coro::yield( i + j ); } If bind is adopted, the implementation could use it to store directly the actual parameters, instead of needing to store them in the self_t instance and them returning them when yield is called. */As// Boost.Coroutine is able to transfer user exceptions, and there is no difference between calling to coroutine<>::self_t::yield_break()/ and throwing/coroutine_terminated,/both (/coroutine<>::self_t::yield_break()/ and throwing/coroutine_terminated)/be removed from the library. The same applies for generators. * noexcept specifier should be added to class coroutine { // ... coroutine() BOOST_NOEXCEPT; coroutine( coroutine && other) BOOST_NOEXCEPT; coroutine & operator=( coroutine && other) BOOST_NOEXCEPT; explicitoperator bool() const BOOST_NOEXCEPT; bool is_complete() const BOOST_NOEXCEPT; //... }; void swap( coroutine & l, coroutine & r) BOOST_NOEXCEPT; The same applies to generator. * Type-erase on the Allocator parameter as the standard std::packaged_task does. * Make coroutine/generator classes to follow the allocator aware standard protocol adding the constructor with the standard allocator. A specializations of the use_allocator template should be added for this purpose. * Moving some of the coroutine/generator optional parameters to a coro::attributes class could simplify the interface std::size_t size = ctx::default_stacksize(), flag_unwind_t do_unwind = stack_unwind, bool preserve_fpu = true, * The lib shouldn't throw when preconditions are not satisfied, assert should instead. * It is a shame that the library can not support completely move semantics for the coroutine parameters, as the used boost::tuple don't support it yet. I would like this point be addressed before the first release so that there is no break in the interface when this will be solved either using boost::tuple, boost::fusion::tuple or std::tuple. At a last resort the library could either define a macro that allows to parameterize the tuple implementation, or alternatively it could implement a wrapper that forwards to the best implementation. * As others have noted, providing a view of a generator as an output iterator will be welcome. Viewing it as a range will be also appreciated. BTW, I don't like the alternative using optional as the result of a generator. Following the output iterator concept the access is defined only if the generator has not finished. - What is your evaluation of the implementation? I have not a deep opinion as I have not found the time to inspect it. At first glance, it seems that the inheritance hierarchy is deeper than needed and the use of the pre-processor to manage with variadic templates hides a possible good design (as it is usual in those cases). Maybe now that most of the c++ compilers support them, using the preprocessor is less imperative. - What is your evaluation of the documentation? I find the documentation a little bit sparse and contain a lot or typos and minor errors. I would appreciate if the original Boost.Coroutine documentation from Giovannii were not lost, at least for Motivation and Tutorial parts. I would appreciate also if the documentation include the rationale to don't include symmetric coroutines and show how the current library can be used to solve the problems the missing features provide, why not as examples. * showing the signature in the documentation will be more informative. template< typename Signature, typename Allocator = ctx::stack_allocator >class coroutine; template< typename R, typename ...ArgTypes, typename Allocator > class coroutine<R(ArgTypes...)> { public: class self_t { public: tuple<ArgTypes...>yield( R); void yield_break(); }; * documentation for the following constructor is missing in the reference template< typename Fn > coroutine( Fn && fn, std::size_t size = ctx::default_stacksize(), flag_unwind_t do_unwind = stack_unwind, bool preserve_fpu = true, Allocator alloc = Allocator() ); *The example typedef boost::coro::coroutine< void(int) > coro_t; void f( coro_t::self_t & self, int i) { ... self.yield(); ... } coro_t c( boost::bind( f, _1) ); c( 7); doesn't compiles. It should be something like coro_t c( boost::bind( f, _1, _2) ); BTW, I don't see the need to use boost::bind in this case, as coro_t c( f ); works as well. The superfluous uses of bind in the documentation should be removed: - What is your evaluation of the potential usefulness of the library? Very useful. coroutines and generators are some useful constructions that are missing in the language. - Did you try to use the library? With what compiler? Did you have any problems? Yes. I used gcc-4.2.1,4.6.0, 4.7.0,clang2.9 andclang-3.0 on darwin. I had no problem running the provided examples and tests. I have written some examples. - How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? I have read the documentations of Oliver and Giovanii libraries, followed the review and used the library. - Are you knowledgeable about the problem domain? From the theoretical point of view, yes. Never used in practice. Finally, my vote is YES. Even if the current interface has some drawbacks that should be mentioned in the documentation, I think I Boost.Coroutine is already useful and should be accepted into Boost. Best, Vicente P.S. Maybe I have forgotten to include some of the remarks I did on preceding posts.

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[optional] using gdb to inspect optional value
by Pedro Larroy 13 Sep '12

13 Sep '12

Hi Is there a way to inspect an optional with gdb? I had to remove the usage if boost::optional as it caused me trouble to inspect the value. Thanks. Pedro.

2 1

[asio] New feature: timeout for poll()
by Max Che 13 Sep '12

13 Sep '12

Hello. My previous letter contained errors. Here is another letter. I want to use win_iocp_io_service::poll() with timeout. poll() + timeout => poll() functional and free waitable timer! GetQueuedCompletionStatus() (and epoll(), kqueue()) allows to use that. Can anyone add (restore) this feature?

1 0

[shared_ptr] Patch adding weak_use_count and weak_from_this
by Brent Lewis 12 Sep '12

12 Sep '12

These are useful for debugging, similarly to shared_ptr::use_count. Specifically, you can check for dangling pointers by replacing ordinary pointers with weak pointers, and checking the count inside a destructor. The patch is for boost 1.49 and is attached.

1 0

[build] 1.49 unable to bootstrap boost
by yuri kilochek 12 Sep '12

12 Sep '12

Not sure if this goes here. On Windows 7, when I try to do bootstrap on a freshly unzipped boost 1.49 at the root directory, I get the following output: Building Boost.Build engine But that is as far as it gets before os terminates whatever it is doing with this (roughly translated from russian): **** STACK SIZE EXCEEDED **** **** WHILE PERFORMING RECURSION IN BATCH MODE **** Recursion depth=654, Stack usage=90 percent. **** BATCH PROCESSING ABORTED **** Is there a way to build boost bypassing this?

4 3

[context] Linux x64 / printf
by Daniel Larimer 12 Sep '12

12 Sep '12

I modified the 'jump.cpp' example and added the line marked CRASH in f1() #include <cstdlib> #include <cstring> #include <iostream> #include <vector> #include <boost/assert.hpp> #include <boost/context/all.hpp> namespace ctx = boost::ctx; ctx::fcontext_t fcm, fc1, fc2; void f1( intptr_t) { std::cout<<"hello "<<0; // WORKS printf( "hello %d", 0 ); // <<< CRASH std::cout << "f1: entered" << std::endl; std::cout << "f1: call jump_fcontext( & fc1, & fc2, 0)" << std::endl; ctx::jump_fcontext( & fc1, & fc2, 0); std::cout << "f1: return" << std::endl; ctx::jump_fcontext( & fc1, & fcm, 0); } void f2( intptr_t) { std::cout << "f2: entered" << std::endl; std::cout << "f2: call jump_fcontext( & fc2, & fc1, 0)" << std::endl; ctx::jump_fcontext( & fc2, & fc1, 0); BOOST_ASSERT( false && ! "f2: never returns"); } int main( int argc, char * argv[]) { ctx::stack_allocator alloc1, alloc2; fc1.fc_stack.base = alloc1.allocate(ctx::minimum_stacksize()); fc1.fc_stack.limit = static_cast< char * >( fc1.fc_stack.base) - ctx::minimum_stacksize(); ctx::make_fcontext( & fc1, f1); fc2.fc_stack.base = alloc2.allocate(ctx::minimum_stacksize()); fc2.fc_stack.limit = static_cast< char * >( fc2.fc_stack.base) - ctx::minimum_stacksize(); ctx::make_fcontext( & fc2, f2); std::cout << "main: call start_fcontext( & fcm, & fc1, 0)" << std::endl; ctx::jump_fcontext( & fcm, & fc1, 0); std::cout << "main: done" << std::endl; return EXIT_SUCCESS; }

4 9

[mpi] scatterv, gatherv and Boost.MPI status
by Alain O Miniussi 11 Sep '12

11 Sep '12

Hi, Despite the fact that https://svn.boost.org/trac/boost/ticket/5292 has been sitting there for some time, the documentations still states that MPI_Allgatherv => most uses supported by all_gather (from 1.51.1). It seems the ticket wasn't commited nor refused. Is there a reason why a c++ MPI_gatherv equivalent is useless in Boost.MPI ? Overall, there seems to be a few other tickets in the same situation in the mpi lib. Which raises another question: what is the exact status of Boost.MPI ? is it still maintained ? is it worth submitting tickets or proposing patches to it or is it safer to move back to the C API ? Best regards Alain

1 0

FW: [Review] Coroutine review starts today, September 3rd, ends September 12th
by Hartmut Kaiser 11 Sep '12

11 Sep '12

This is just a reminder that the review of Oliver's Boost.Coroutine is ending tomorrow (see below for the initial announcement). Please get your reviews in as soon as possible. If you need more time, please let me know. Regards Hartmut --------------- http://boost-spirit.com http://stellar.cct.lsu.edu > -----Original Message----- > From: Hartmut Kaiser [mailto:hartmut.kaiser@gmail.com] > Sent: Monday, September 03, 2012 6:46 AM > To: boost(a)lists.boost.org > Subject: {Review] Coroutine reviewstarts today, September 3rd > > > Hi all, > > The review of Oliver Kowalke's Boost.Coroutine library starts today, > September 3rd 2012, and will end on September 12th. > I really hope to see your vote and your participation in the discussions > on the Boost mailing lists! > > ----------------------------------------------------- > > About the library: > > Boost.Coroutine provides templates for generalized subroutines > (coroutines) which allow multiple entry points for suspending and resuming > execution at certain locations. It preserves local state/data and allows > re-entering subroutines more than once (useful if state must be kept > across function calls). Coroutines can be viewed as a language-level > construct providing a special kind of control flow. > > You can download the library and the view documentation here: > > docs: http://ok73.ok.funpic.de/boost/libs/coroutine/doc/html/ > src: http://ok73.ok.funpic.de/boost.coroutine.zip > > --------------------------------------------------- > > Please always state in your review, whether you think the library should > be accepted as a Boost library! > > Additionally please consider giving feedback on the following general > topics: > > - What is your evaluation of the design? > - What is your evaluation of the implementation? > - What is your evaluation of the documentation? > - What is your evaluation of the potential usefulness of the library? > - Did you try to use the library? With what compiler? Did you have any > problems? > - How much effort did you put into your evaluation? A glance? A quick > reading? In-depth study? > - Are you knowledgeable about the problem domain? > > Regards Hartmut > Review Manager

1 0

[thread] std::this_thread reference in docs
by Lars Viklund 11 Sep '12

11 Sep '12

Hi list. Since 1.50.0, the Boost.Thread documentation has started making references to std::this_thread::get_id() like in [1]. This is a bit strange, considering that the Thead library itself to my knowledge does not require C++11 (yet). Is this an accidental change? Should one read this as that the error condition is not achievable on C++03? 1.49: Preconditions: this->get_id()!=boost::this_thread::get_id() 1.50 (and 1.51): Preconditions: the thread is joinable. Error Conditions: resource_deadlock_would_occur: if deadlock is detected or this->get_id() == std::this_thread::get_id(). [1] http://www.boost.org/doc/libs/1_51_0/doc/html/thread/thread_management.html… [2] http://www.boost.org/doc/libs/1_49_0/doc/html/thread/thread_management.html… -- Lars Viklund | zao(a)acc.umu.se

2 1

[context] Trying to compile Coroutine on trunk
by Vicente J. Botet Escriba 11 Sep '12

11 Sep '12

Hi, I don't reach to compile Boost.Coroutine under Mac using trunk ../../../boost/coroutine/coroutine.hpp:14:45: error: boost/context/stack_allocator.hpp: No such file or directory ../../../boost/coroutine/coroutine.hpp:15:41: error: boost/context/stack_utils.hpp: No such file or directory Are you changing the interface of Boost.Context? Best, Vicente

4 4

[log] library status?
by Igor R 11 Sep '12

11 Sep '12

Hello, Is Boost.Log expected to enter one the Boost version soon? I see that its last update on sourceforge took place about a year ago... Thanks.

3 2

quest for member ‘read_some’ in ‘socket’, which is of non-class type ‘boost::asio::ip::tcp::socket* {aka boost::asio::basic_stream_socket<boost::asio::ip::tcp>*}
by neha_mysql 11 Sep '12

11 Sep '12

Hii, i am trying to execute a code and im getting error in this part of the code(in line no 3) for(;;) char buf[4]; size_t len = socket.read_some(boost::asio::buffer(buf,4)); if(error == boost::asio::error::eof) break; else if(error) throw boost::system::system_error(error); std::cout << "[!]"; std::cout.write(buf.data(), len); } The error is *" quest for member ‘read_some’ in ‘socket’, which is of non-class type ‘boost::asio::ip::tcp::socket* {aka boost::asio::basic_stream_socket<boost::asio::ip::tcp>*}"* -- View this message in context: http://boost.2283326.n4.nabble.com/quest-for-member-read-some-in-socket-whi… Sent from the Boost - Dev mailing list archive at Nabble.com.

2 1

[Review.Coroutine] More comments, questions and suggestions
by Vicente J. Botet Escriba 11 Sep '12

11 Sep '12

Hi, I understand Oliver that you are busy as all of us and that it is better to provide first the minimal scope you are confident with. I expect however that you will add symmetric coroutines based on the work done by Giovanni in a near future. BTW, adding a link to the Giovanni documentation will be welcome. I have more questions concerning the interface before finishing my review: * How the library behaves when the coroutine parameters are const& typedef boost::coro::coroutine< int( AType const& ) > coro_t; int fn( coro_t::self_t & self, AType const& v) { ???j = self.yield( v.get_int() ); /// ... } What should be the type (???) of j? Does AType const& works? * Have you tested with other kind of parameters? arrays, pointers, ... It would be great if the documentation includes some examples, with the different types that can be used. * The way the parameters of the coroutine call are retrieved the second time is a little bit disturbing at a first glance, but once you understand how this works, it is not so complex (This applies to the library under review and the original one, as both share the same design). I don't know if the the self object couldn't store the parameter binding, so that the user will not be concerned by the yield result type. typedef boost::coro::coroutine< int( int) > coro_t; int fn( coro_t::self_t & self, int i) { // binds current parameters to the self object. Done only once. self.bind(i); // *** std::cout << "fn(): local variable i ==" << i << std::endl; // save current coroutine context // transfer execution control back to caller // no need to assign the result. It is up to yield to fill the binded parameters. self.yield(i); // OTHERS *** // i == 10 because c( 10) in main() and i has been bound in self. std::cout << "fn(): local variable i ==" << i<< std::endl; return i; // LAST } I don't know this bind design introduce more problems that it could solve. I don't know neither if this could degrade the performances. * In the preceding example there is an asymmetry between the value returned the last time and the others. self.yield( i); // OTHERS return i; // LAST What about forcing the coroutine function return void, as it is the case now for the generator? voidfn( coro_t::self_t & self, int i) { self.bind(i); std::cout << "fn(): local variable i ==" << i << std::endl; self.yield(i); std::cout << "fn(): local variable i ==" << i<< std::endl; self.yield(i); } This should help to simplify user code, isn't it? * I don't know if you have reached to make the StackAllocator standard compliant, but if this is the case you could add also a specializations of the use_allocator template so that Boost.Container can take it in account. Best, Vicente

5 13

[Review.Coroutine] Lifetime of coroutine parameters
by Vicente J. Botet Escriba 11 Sep '12

11 Sep '12

Hi, I have some concerns about the lifetime of the coroutine parameters. Surprisingly (well not really), the following example doesn't fails at *1*. This is because the coroutine have access to its coroutine parameters *2*, which has a sens only for the first time the coroutine is called. Once the first call to yield return, the memory these parameter *3* can point to trash, as the example shows. typedef int TT; typedef boost::coro::coroutine< void(TT&) > coro_TT; void lifetime( coro_TT::self_t & self, TT& i ) // *2* { i=1; TT& j = self.yield(); std::cout << i << j << std::endl; i=2; // *3* UNSAFE access to i self.yield(); } void test_lifetime() { coro_TT c( boost::bind( lifetime, _1, _2) ); { int k = 0; c( k ); BOOST_CHECK(k = 1); } { int k = 0; int i = 0; c( i ); BOOST_CHECK(k = 2); // *1* std::cout << i << k << std::endl; } } This could hide errors that are difficult to catch. In addition to merit to be mentioned in the documentation as a limitation of the current library interface I really think that it merits to see if this can be solved. Best, Vicente

3 3

[Variant] C++11 variadic template implementation
by Florian Goujeon 11 Sep '12

11 Sep '12

Hi Boosters, I'd like to know if anybody were working on a C++11 version (using variadic templates) of Boost.Variant. I currently use the 'classic' version in my project, but since I need more-than-20-type variants, the compilation take a lot of time (extending the number of types that variant can support forces you to disable the use of precompiled headers). Plus, I'll need to use 70 type variants (MPL lists are physically limited to 50 types). If nobody has started to implement such a version yet, I'd be pleased to contribute. I've written an implementation. It's incomplete and far from perfect, but it could (hopefully) be a viable working basis.

6 16

[HELP] fatal error LNK1120: 5 unresolved externals
by Seow Hui, Saw 10 Sep '12

10 Sep '12

Dear Sir/ Madam, A very good day to you. I installed boost 1.50 installer (32-bit) which downloaded from http://www.boostpro.com/download/ and did the appropriate settings (including CGAL) in Microsoft Visual Studio 2010. I would like to run the following sample code: #include <iostream> #include <CGAL\Exact_predicates_inexact_constructions_kernel.h> #include <CGAL\convex_hull_2.h> typedef CGAL::Exact_predicates_inexact_constructions_kernel K; typedef K::Point_2 Point_2; int main() { Point_2 points[5] = { Point_2(0, 0), Point_2(10, 0), Point_2(10, 10), Point_2(6, 5), Point_2(4, 1) }; Point_2 result[5]; Point_2 *ptr = CGAL::convex_hull_2( points, points+5, result ); std::cout << ptr - result << " points on the convex hull" << std::endl; return 0; } There are no errors during compilation but there are errors during the build as shown below: 1>------ Build started: Project: Cgal_Hello, Configuration: Debug Win32 ------ 1>libboost_system-vc100-mt-gd-1_50.lib(error_code.obj) : error LNK2005: "public: __thiscall std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &)" (??0?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@QAE@ABV01@@Z) already defined in msvcprtd.lib(MSVCP90D.dll) 1>libboost_system-vc100-mt-gd-1_50.lib(error_code.obj) : error LNK2019: unresolved external symbol "__declspec(dllimport) void __cdecl std::_Xout_of_range(char const *)" (__imp_?_Xout_of_range@std@@YAXPBD@Z) referenced in function "public: void __thiscall std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >::_Xran(void)const " (?_Xran@?$basic_string@DU ?$char_traits@D@std@@V?$allocator@D@2@@std@@QBEXXZ) 1>D:\Cgal_Hello\Debug\Cgal_Hello.exe : fatal error LNK1120: 5 unresolved externals Can anyone please help me with this issues? desperately need help... In addition, if I have installed the installer, do I still have to use bjam.exe to build the libraries? Hope to hear from you soon. Thank you very much. -- Best Regards, Saw

2 1

[program_option] Better compiler checks?
by Klaim - Joël Lamotte 10 Sep '12

10 Sep '12

Hi I was adding program_option to my prorgam when I discovered a related leak. Fortunately it was false positive, but it pointed a hidden problem. I used: - Visual Studio 2012 - Boost 1.51.0 - Visual Leak Detector to detect the leak This, generate the leak: {{{ #include <boost/program_options.hpp> int main() { namespace bpo = boost::program_options; bpo::options_description options( "Options" ); options.add_options() ( "test" , "Test." ) , ( "value" , bpo::value<int>(), "Value." ) ; } }}} The second option is leaking. The reason is because of the comma in the beginning of the line. I first added it by reflex when using function arguments so it took me some time to find what was leaking. Part of the time I spend was figuring out why it don't leak if you don't set a value type: {{{ #include <boost/program_options.hpp> int main() { namespace bpo = boost::program_options; bpo::options_description options( "Options" ); options.add_options() ( "test" , "Test." ) , ( "value" , "Value." ) // no leak but still wrong! ; } }}} The main problem I see with this is that it is compiled without any problem nor warning. So here is my question: Would it be possible to forbid comma operator with options_description_easy_init? I added a ticket for this, #7361 : https://svn.boost.org/trac/boost/ticket/7361 Joel Lamotte

1 0

Forward declaration headers
by Jens Auer 10 Sep '12

10 Sep '12

Hi, we often have to provide forward declarations of boost types by hand when we write interfaces. This is kind of dangerous because we will have to change the forward declarations when the boost libraries change and impossible for typedefs. Shouldn't there be a standard forward declaration headers in each of the boost libraries? Best regards, Jens

2 1

Sizes, signed and unsigned integers, MPL and Fusion
by Mathias Gaunard 10 Sep '12

10 Sep '12

Hi folks, I am writing this message to bring to your attention ticket #7304 <https://svn.boost.org/trac/boost/ticket/7304> Sizes of fusion sequences are of type 'int', because it mimics MPL. However, sizes of standard containers, some of which are fusion sequences, are of type std::size_t, which is unsigned. This seems a bit inconsistent, and can lead to unexpected signed/unsigned mismatch warnings in certain scenarios. Should both MPL and Fusion be modified to use unsigned size types? I think it is best to discuss this with the whole of Boost.

2 1

Making use of extern template
by Jens Auer 10 Sep '12

10 Sep '12

Hi, I tried to use C++11 extern template mechanism to reduce the turn-around time for our main project, but it turns out that the way people write template code in libraries is not suited well for that purpose. I tried to explicitly instantiate the template base class of boost::posix_time_ptime, date_time::base_time<ptime, posix_time_system>, because ptime is a value class which is used quite often in our project. The base class is then instantiated in every translation unit and later removed by the linker (we use MS Visual C++ 2010. The linker is single threaded and dead slow). The problem with extern template and the boost library is that inline template code is still instantiated in every translation unit even when using extern template, so it basically has no effect with the current boost code: $14.7.2.10: "Except for inline functions and class template specializations, explicit instantiation declarations have the effect of suppressing the implicit instantiation of the entity to which they refer." I would like to have a discussion of how boost could support extern template to reduce built times, maybe by changing the coding style to not write template code inline and use extern template in the library to automatically suppress instantiation of library instantiations such as the base class of ptime. Best regards, Jens

1 0

[atomic, 1.52] adoption & merge request
by Tim Blechmann 09 Sep '12

09 Sep '12

hi all, boost.atomic has been accepted as boost library and has been in trunk for a few months. however there are some issues and pending patches and helge bahmann, the original author, did not comment on any of them. therefore, hartmut and me would like to adopt the library temporarily to support helge, and merge these pending patches. we also like to add the library into the release branch, so that it will make it into 1.52. any objections? thanks, tim

3 2

[atomic] ia32/cmpxchg8b fix
by Tim Blechmann 09 Sep '12

09 Sep '12

one of my users reported an issue with atomic on gcc/ia32, related to const-correctness. ok to commit this fix? thanks, tim Index: boost/atomic/detail/gcc-x86.hpp =================================================================== --- boost/atomic/detail/gcc-x86.hpp (revision 80433) +++ boost/atomic/detail/gcc-x86.hpp (working copy) @@ -1556,11 +1556,11 @@ template<typename T> T -platform_load64(volatile T * ptr) +platform_load64(const volatile T * ptr) { T expected = *ptr; do { - } while (!platform_cmpxchg64_strong(expected, expected, ptr)); + } while (!platform_cmpxchg64_strong(expected, expected, const_cast<volatile T*>(ptr))); return expected; }

2 1

Re: [boost] C++ Boost library - passing Shared pointer to a function
by abhishek goswami 09 Sep '12

09 Sep '12

I am looking for a project which is converting c malloc/realloc to shared_ptr. During my Analysis, I found the issue Can anyone provide me some input how to fix below issue typedef boost::shared_ptr<Employee_t> srdpointer; srdpointer ptr((Employee_t*)malloc(sizeof(Employee_t)),std::ptr_fun(free)); I need to pass the shared pointer which will allocate memory Pointed by the ptr. Something like this. void allocateBlocks(int **ptr, int *cnt) { *ptr = (int*)malloc(sizeof(int) * 10); *cnt = 10; /*do something*/ } int main() { int *p = NULL; int count = 0; allocateBlocks(&p, &count); /*do something*/ free(p); } How can I achieve the similar functionality using shared ptr as shown in above code

2 1

[intrusive] patch to resolve compiler error for WinCE
by David Deakins 09 Sep '12

09 Sep '12

Hi Ion, I had a little bit of time to look into the compile error mentioned in ticket 6841 and determine a patch from detail/mpl.hpp that I think should resolve it. The patch is attached to that Trac ticket, although I could also just go ahead and apply it if you like. Thanks, -Dave

2 1

[Review.Coroutine] Some comments
by Vicente J. Botet Escriba 09 Sep '12

09 Sep '12

Hi, thanks Oliver to move the Coroutine library to a Boost review ready proposal. Before doing a formal review, I have some comments, suggestions and questions after a quick reading. Design ==== * I don't know if showing the signature in the documentation will be more informative. This will avoid, in particular, the be forced to explain what T and R and in the the current declaration. Could you replace template< typename Signature, typename Allocator = ctx::stack_allocator > class coroutine { public: class self_t { public: T yield( R); void yield_break(); }; by template< typename Signature, typename Allocator = ctx::stack_allocator >class coroutine; template< typename R, typename ...ArgTypes, typename Allocator > class coroutine<R(ArgTypes...)> { public: class self_t { public: tuple<ArgTypes...>yield( R); void yield_break(); }; * Could you add the following noexcept specifier? class coroutine { // ... coroutine() BOOST_NOEXCEPT; coroutine( coroutine && other) BOOST_NOEXCEPT; coroutine & operator=( coroutine && other) BOOST_NOEXCEPT; explicitoperator bool() const BOOST_NOEXCEPT; bool is_complete() const BOOST_NOEXCEPT; //... }; void swap( coroutine & l, coroutine & r) BOOST_NOEXCEPT; The same applies to generator. * As the template class Allocator is not used to allocate internal memory of the coroutine class. Could the Allocator parameter be renamed StackAllocator? * Could you add an standard Allocator parameter as e.g. the one of packaged_task? 0. template <class F, class Allocator> explicit packaged_task(allocator_arg_t, const Allocator& a, F&& f); C++ International Standard * I understand that the Boost.Context Allocator parameter is part od the class, as context is a low-level class, but coroutine is more high level. Is there a possibility to type erase the StackAllocator (and preceding Allocator) template parameter, as packaged_task do? This will allow to store coroutines (and generators) with the same signature in a container even if they don't share the Allocator. template<typename>class coroutine; template< typename R, typename ...ArgTypes > class coroutine<R(ArgTypes...)> { public: //... template< typename Fn,typename Allocator> generator( Fn fn, std::size_t size = ctx::default_stacksize(), flag_unwind_t do_unwind = stack_unwind, bool preserve_fpu = true, Allocator alloc = Allocator() ); //... }; * Parameters and move semantics. Could the signature parameters be rvalue references? R operator()(A0 a0, ..., A9 a9); I'm asking this because I think that Boost.Tuple has not implemented yet move semantics. * What about moving some of the coroutine/generator optional parameters to a coro::attributes class std::size_t size = ctx::default_stacksize(), flag_unwind_t do_unwind = stack_unwind, bool preserve_fpu = true, * Usually (at least in the C++ standard) a function doesn't throws because of its preconditions are not satisfied. Preconditions: |size| > ctx::minimum_stacksize(), |size| < ctx::maximum_stacksize() when ! ctx::is_stack_unbound(). Effects: Creates a generator which will execute |fn|. If |do_unwind| is |stack_unwind| the destructor of |*this| unwinds the stack before destructing it. If |preserve_fpu| is |true| the floating-point registers are preserved between context switches. Throws: /invalid_argument/ if a precondition is not satisfied. Should the function throw in this case? This should be coherent with |Result operator()()| <http://ok73.ok.funpic.de/boost/libs/coroutine/doc/html/coroutine/generator/…> Preconditions: |*this| is not a /not-a-generator/, |! is_complete()|. which doesn't throws any specific exception if the preconditions are not satisfied. . Documentation ========= coroutine.html s/it can migrated between threads/it can migrate between threads/ s/yield_return/yield_break/ * documentation for the following constructor is missing in the reference template< typename Fn > coroutine( Fn && fn, std::size_t size = ctx::default_stacksize(), flag_unwind_t do_unwind = stack_unwind, bool preserve_fpu = true, Allocator alloc = Allocator() ); Best, Vicente

4 12

Re: [boost] [Boost-users] boost 1.51.0 bz2 archive observations
by Daniel James 08 Sep '12

08 Sep '12

>From the user list: On 31 August 2012 16:39, Aras Vaichas <aras.vaichas(a)gmail.com> wrote: > > There is a slight difference between the 1.51.0 and 1.50.0 boost bz2 files. > > e.g. > \boost_1_50_0.tar.bz2\boost_1_50_0.tar\boost_1_50_0\ > \boost_1_51_0.tar.bz2\boost_1_51_0.tar\.\boost_1_51_0\ This is causing problems for some people's build scripts. The attached patch should fix this.

2 1

boost::assign::map_list_of and references?
by David Hagood 08 Sep '12

08 Sep '12

I was trying to initialize a map using map_list_of, and ran into what I consider an undesirable behavior: class stooge { public: stooge(); stooge(const stooge &); stooge &operator =(const stooge &); }; typedef std::map<std::string,const stooge &> MyMap_t; extern const stooge larry,moe,curly; MyMap_t mymap = boost::assign::map_list_of ("larry",larry) ("moe",moe) ("curly",curly); The above leaves mymap full of bogus references - it seems map_list_of is creating temporary copies of the objects, rather than taking their references, and then the map takes references to those temporaries, and blooley! Changing the assignment to: MyMap_t mymap = boost::assign::map_list_of<std::string, const stooge &> doesn't change anything. (and for various reasons, making stooge noncopyable is not an option). This is under gcc 4.5 i686 target. Am I "doing it wrong" or is this an issue with map_list_of?

1 0

[config] [result_of] Now VC++11 selects decltype-based result_of by default
by Michel Morin 08 Sep '12

08 Sep '12

On VC++11, result_of (on trunk) uses decltype-based implementation by default from r80453: https://svn.boost.org/trac/boost/changeset/80453 Note that VC++11 does not have a C++03/C++11 compiler switch and it always runs in a C++11 mode. Regards, Michel

1 0

[result_of] Usage guidelines
by Andrey Semashev 08 Sep '12

08 Sep '12

Hi, I wonder what is the correct way of declaring polymorphic function object result types and how to use result_of template with regard to argument types. If a function object receives arguments by reference, should its member result<> template be specialized for reference types as well? Also, should result_of<> for this function be instantiated with reference argument types? struct my_foo { template< typename > struct result; // Is this correct? template< typename ArgT > struct result< my_foo(ArgT) > { typedef ArgT type; }; // Or is this correct? template< typename ArgT > struct result< my_foo(ArgT const&) > { typedef ArgT type; }; template< typename ArgT > ArgT operator() (ArgT const& arg) const { return arg; } }; I realize that I can provide both result<> specializations and it will work either way. But when there are more than one argument the specializations begin to pile quickly. Consider also rvalue references and const and non-const qualified my_foo. Another question I have is how to use result_of<> when my_foo is external (i.e. provided by a third party library)? // Which one is the right way? typedef result_of< my_foo(int) >::type result_type1; typedef result_of< my_foo(int const&) >::type result_type2; I cannot know what result<> specializations are provided by my_foo, so probably there isn't an ultimate answer. But perhaps there are some guidelines or best practices? I've looked at result_of docs but there are no recommendations on this.

5 11

Interest in UDL suffixes for built-in and some standard library types?
by Peter Sommerlad 08 Sep '12

08 Sep '12

Dear boost members, I am preparing a paper for the next C++ standardization meeting for providing user-defined-literals for some standard types. b (and a variety of derivations lik bULL) for binary integer literals as in 101b s for std::string as "hello, world!"s s, h, min, etc. for std::chrono::duration literals such as 0xfh for 15 hours i, r for creating std::complex literals see http://wiki.hsr.ch/PeterSommerlad/wiki.cgi?LiteralsForBinaryStringComplexDu… for the paper draft. It also includes machinery to parse integers using the template version of a user-defined literal, because using constexpr operator"" foo(unsigned long long bar); overload loses the ability to treat the number bar as a compile-time constant, e.g., to use as template argument further on. Some people told me, such a facility would be nice in its own way, to be used by other authors of UDL constexpr overloads. I wonder if there is interest to provide standard conforming versions of my implementation (including the required _ prefix) for boost (which would require to clean up things a bit beforehand). Such a boost.suffixes library would only work with C++11 capable compilers that actually implement UDL and constexpr in combination (for some uses the constexpr is not required). gcc4.7.1 is fine, for example, my version of clang didn't do constexpr yet (that might have changed). Feedback, encouragement and thoughts are welcome. TIA and Best Regards Peter. -- 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

2 1

Newbie question: Can't see my own posts
by Peter Sommerlad 07 Sep '12

07 Sep '12

Hi, it seems to me that I cannot see my own posts. For one containing a hyperlink I got a post confirmation but it never reached me: > Your message entitled > > Interest in UDL suffixes for built-in and some standard library types? > > was successfully received by the Boost mailing list. Did anybody see that message? Regards and thanks for your help Peter. -- 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

2 1

[heap] typedef T gets prevalence over template parameter
by Alex Hagen-Zanker 07 Sep '12

07 Sep '12

Hi, The d_ary_heap does not compile (in VS2010) when the Comparison class contains a typedef T. The typedef takes prevalence over the template parameter T when the heap is derived from the Comparison class. I.e. the following pattern occurs: template<class T, class Cmp> struct heap_base : Cmp { typedef T value_type; // value_type = Cmp::T } I don't know if this is a bug, a user issue, or a compiler issue. But it caused me a lot of headache when I was trying to apply Jeremiah's indirect_cmp with Boost.Heap. See below for a complete failing example. Kind regards, Alex #include <boost/heap/d_ary_heap.hpp> struct less { typedef int T; bool operator()(const int& a, const int& b) const { return a < b; } }; int main() { boost::heap::d_ary_heap<int, boost::heap::compare<less>, boost::heap::arity<4> > my_heap; return 0; }

3 5

[Review] Coroutine : Christopher's Review
by Christopher Kormanyos 07 Sep '12

07 Sep '12

(I lost the initial review announcement.) Yes, I vote that Coroutine should be accepted into Boost! General impression of the library: Coroutine offers enormous potential for programming regimes such as communications software and embedded systems design. For example, a lightweight event/alarm-based cooperative multitasking scheduler for embedded systems can be readily implemented usingCoroutine combined with a timer resource. Oliver has selected a sensible granularity for Coroutine. It includes Boost.Context, Coroutine and the proposed Boost.Fiber. 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. The documentation is terse, yet complete and informative. The examples are good. The design of Coroutine is clearly thought through. In particular, the separation of Coroutine from Context allows for porting to other systems with minimal effort and maximum reliability and code re-use. How long did I work with Coroutine? I worked for about 1 week with Coroutine. In particular, I worked very intensively with Coroutine for 2 days straight. I used Coroutine with VS2010, VS2012-RC and several GNU compilers. I spent a lot of time deeply embedding Coroutine in a hard real-time system. This experience has led to the comments and suggestions shown below. Am I familiar with the regime of Coroutine? Yes. I am absolutely familiar with the regime of Coroutine. I have authored many cooperative multitasking schedulers for a variety of CPU architectures and shipped them in tens of millions of devices. Suggestions for Coroutine: I have several suggestions for Coroutine, none of which stand in the way of immediate acceptance into Boost. 1) The code may potentially benefit from some clean-up. In particular, there is a mixture of tabs and spaces in the code, possibly resulting from programming over two or more time epochs with different styles. A simple reformat will clean this up. Coroutine is desperately needed in the embedded systems community. Along these lines, I suggests some extensions. 2) There should be, let's say, a *lightweight* version (or configuration) of Coroutine for embedded systems 3) The lightweight version can not use the non-placement version of new(). The internal details of a coroutine are stored in the class as a pointer created with non-placement new(). The lightweight version could add a parameter for user-supplied memory and create the coroutine implementation details with placement-new(). 4) Furthermore, the lightweight version should not not use any exceptions whatsoever. I spent two solid hours removing all traces of exceptions while embedding Coroutine. The result was a lightweight mechanism that only costed a few kilobytes of program code. 5) We need to work together to create more contexts for different CPU architectures. The ARM(R) context that is present in Boost.Context uses several ASM operations that my ARM(R) Cortex(R)-M3 does not support. For this reason, I could not complete my benchmark. We can work on this in the future. Thank you for your efforts and good luck! Best regards, Chris.

3 2

[rational] Over/underflow checked update ready for comments
by Dan Searles 07 Sep '12

07 Sep '12

Le 06/09/12 04:28, Dan Searles a ?crit :>Le 06/09/12 04:28, Dan Searles a ?crit : >>>> For those interested in the rational number class, see: >>>> https://svn.boost.org/svn/boost/sandbox/rational >>>> >>>> Requesting comments on the code, and review for >>>> inclusion in the next release. >>>> >>>> >>> Hi, >>> >>> the enum type could follow the one defined in >>> http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2012/n3352.html >>> "When an overflow does occur, the desirable behavior depends on the >>> application, so programmers may specify the overflow mode with a value >>> of type |enum class overflow|. The possible values are: >>> >>> |impossible| >>> Programmer analysis of the program has determined that overflow >>> cannot occur. Uses of this mode should be accompanied by an argument >>> supporting the conclusion. >>> |undefined| >>> Programmers are willing to accept undefined behavior in the event of >>> an overflow. >>> |modulus| >>> The assigned value is the dynamic value mod the range of the >>> variable. This mode makes sense only with unsigned numbers. It is >>> useful for angular measures. >>> |saturate| >>> If the dynamic value exceeds the range of the variable, assign the >>> nearest representable value. >>> |exception| >>> If the dynamic value exceeds the range of the variable, throw an >>> exception of type |std::overflow_error|. >> 'impossible' and 'undefined' are effectively the same thing, and >> equivalent to the 'no check' currently implemented. >Yes and not. Maybe from the point of view of the library, but this is a >useful information from the user point of view. So for the 'impossible' case, what should the library do when there is an over/underflow? >>> 'modulus' makes >>> more sense for the fixed point class that it's being described for >>> than rational numbers. I'm not sure a useful definition can even be >>> made for rationals. >>You are right. modulus for rational has not a clear sense. >> 'Saturate' sounds like it might be useful, but gets problematic >> quickly when there is under/overflow within the largest/smallest >> range limits. >Could you clarify? 'Saturate' implies returning the max value when the computed result is larger than can be represented, and returning the min value when the computed is smaller (more negative) than can be represented, but rationals can underflow between those extremes. For example, what is 1/2 * 1/maxint? >> The point is that if a result of a calculation is not >> exactly representable, you will get an exception to notify you. And of >> course 'exception' is in the new implementation for just that purpose. >A user can be interested in overflow check without exceptions. The >saturate policy should be a good replacement in context where exceptions >are not allowed. I can't quite see a point for there being 3 possible results when there is an overflow: exception, undefined, and ???. Maybe if '???' is a wrong value, but as close as possible? If you don't need the exact answers, float or double would probably be better. Returning zero for ??? might work. >Anyway, you should replace the CamelCase use in the definition of this >new enumeration. I think that basing your definition on the preceding >one could be acceptable. Which ones? Please suggest the names you think would be appropriate. (I tried to pick names that had a low probability of ever being used anywhere else. Common single dictionary words are probably not good.) >>> >>>> BTW, I have no access to the link for the examples and the test. >>> I have not changed those files. The existing examples and test >>> are still valid for the original non-checked case. For the checked >>> case, I have tests which run for hours. The tests for rational >>> instantiated with signed char is exhaustive (there are only so >>> many normalized values. Pairing up each value with every >>> other value on the binary operators doesn't result in much more >>> that 2**32 combinations). For short/int/long long, sets of interesting >>> values are created, and each value is paired up with every other >>> value in the set. I can provide the test drivers if anyone is >>> interested. >>I was interested by the examples and test using the new facility. Could >>you commit them in the sandbox, please? Uploaded the test driver to: https://svn.boost.org/svn/boost/sandbox/rational/Test_Rationals > >Best, >Vicente Thanks Dan Searles

2 1

[Review:Contract] Andrzej's review
by Andrzej Krzemienski 06 Sep '12

06 Sep '12

Hi, First, my vote is "YES": Contract should be accepted into Boost. Now for some details... === MOST IMPORTANT THINGS === (1) Let me start from the most important arguments. "Contract" enables us to use DbC design and tools in C++. This is the only library in C++ that I am aware of that takes DbC seriously, in every detail. In particular, unlike any "simple contract library," it observes that: (a) function pre- and post-conditions need to be part of declaration rather than function implementation, (b) a precondition is something different than a postcondition, (c) It is the execution of destructors of automatic objects that may (re)establish invariants or satisfy postconditions (thus, they need to be checked after destructors have been executed). "Contract" deals with things more detailed than my above list; but even this list is not always addressed in "simple contract libraries". This already gives me the confidence that Lorenzo has a very good understanding of the domain. I believe the community needs BbC framework: it is necessary in order to be able to program consciously. If the responsibilities and expectations are expressed clearly not only is it faster to track bugs, but also programmers would not plant (I think) some bugs from the outset. Of course, contract framework should ideally be provided as language extension; but in the absence of such support we are left with the attempts to implement it via a (possibly too clever) library. "Contract" may also enable and/or speed up the adoption of DbC as language feature in C++, as it will be possible to have a real-world implementation of the framework that people can play with, experiment and assess its usability. (2) An obvious and serious issue with the library is the burdensome syntax you have to use. Given the ambitious task of wrapping each function call with with tests executed before and after, and still leaving the bodies intact, I realize this is not avoidable. In fact I believe Lorenzo made the impossible to make the EDSL as close to normal declaration syntax as possible. Yet, all this may not be enough to call the interface "acceptable". There is a number of issues with it: you have to learn yet another language; compile times increase; if you mis-spell something you have horrible error messages; you cannot use some C++ constructs that you would otherwise use; your IDE and the debugger may be confused (if your contract fails, the bug may be either in your code or in the testing code). I cannot imagine telling my coworkers "from today on we are using Boost.Contract; start learning the new EDSL". I believe that it is not possible to significantly improve the current interface; its limitation is the natural consequence of the nature of the problem. The cost cannot be reduced any more, so the library can only offer even more value. And this is what it does, by (for instance) simplifying the integration with Boost.Concept or adding virtual specifiers. (3) I see it as a useful tool for personal projects, experimentation, learning, validation of usefulness of DbC, a proof of concept for proposal N1962. But the question is, should "Concept" be included into Boost. "Contract" needs inclusion into Boost to gain visibility and some sort of "attestation" and "certification". Only proposing "Contract" for addition to Boost brought attention to DbC: at least it prompted me to learn more. But does Boost need "Contract"? Similar questions have been asked during the review of Boost.LocalFunction. I am not aware of any objective criteria that would help decide in this case. Is this library of "high quality"? Can library with such interface be called "high quality"? But there is no other way to implement DbC in C++ (I believe)? But is it strong enough the argument? Perhaps we should treat some problems as "not implementable" and not include libraries only because there is no cleaner way to implement the tool. The decision to vote "yes" is not easily made. This is a subjective weighing between the offered value and the imposed cost. Personally, I would like to have this library available whenever I download Boost. === GENERAL OBSERVATIONS === (4) The library has very vast and very thorough documentation. It contains tutorials that teach you step by step how to use the library, the introduction into DbC, very detailed rationale, good reference, lots of examples. It is a good "reference documentation". (5) In order to define concept the library defines EDSL for declaring (and defining) classes and functions. This framework as the potential to do other useful things: enable support for concept definition and checking, base class aliases (see N2881), override control, named parameters, noexcept, simplified enable_if (or static if), etc... In fact, perhaps it could be used as a more general EDSL for declarations. This is my loose suggestion to change macro names from BOOST_CONCEPT_CLASS to BOOST_DECL_CLASS, etc, in case someone wants to use the framework for purposes other than contract enforcements. === ISSUES === Here I list a couple of random issues. I do not consider them critical for decision whether to adopt "Contract" to Boost or not. (6) Static assertions: is there any value in providing them, given that we already have this ability in Boost? I see that N1962 decided to abandon them; I am pretty sure the reason was that static_assert was already there. They somehow do not fit conceptually into the model of preconditions, postconditions and invariants. Precondition, for instance tries to detect a run-time condition occurring immediately before a function is called this time. Static assertion is not even executed then. What point is there in putting such assertion into the precondition? Documentation says " static assertions can be selectively disabled depending on where they are specified [...] so it is still important to logically associate them with preconditions, postconditions, etc." -- technically this sentence makes logical sense, but can you think of a single example where this selective disabling of assertions would be useful? What is the point in disabling such assertions at all, if they cost you nothing in run-time? I propose to remove them and give a sort of recommendation that software quality is assured by using a number of fairly independent tools: DbC, concepts, static assertions. (7) Loop variants: They are definitely a good thing to have (and I started using them immediately I learned about them in your documentation!). But they seem to have little to do with "contracts". A contract is (by definition -- I think) something that involves two parties. For instance, precondition implies two parties: one ensures something, the other expects something. Invariants are harder to explain this way, but to me they are like "automated postconditions" (I explain this later on). However with loop variants the situation is different: they are put inside the the code, so no-one expect function author knows about them. The programmer guarantees something only to himself. It is more like assertion (in the sense of C macro assert()), perhaps with better configuration. I only want to make an observation here that this could be proposed irrespectively of contracts (pre-, post-conditions, invariants and subcontracting) -- but I am not proposing this. (8) Block invariants: Same remark as above: they appear to be separate from contracts. Another question is, what is the difference between block invariant and an assertion (like C-style macro assert())? I know, I know: conditional assertion, requirements, selectively disabling them, customizing run-time behavior... But if this is superior to BOOST_ASSERT, would it be correct to say that with Boost.Contract BOOST_ASSERT is no longer needed (except for backward compatibility)? (9) Class invariants: I have an observation, not about yuor library but the way invariants are handled in DbC methodology. As a "contract" (involving two parties) they make sense when checked after any (public) function call: they are a sort of postcondition that is the same for every function: class implementer "ensures" and class user "expects". But when checked before any function execution they are more like a C-assert: the function "expects", but who is supposed to "ensure"? Only any other public function of that class -- but this is already verified by checking postconditions. Somehow checking invariants before function execution is checking the same thing twice. If you find my reasoning even a bit convincing, perhaps it is worth considering adding another config macro: CONTRACT_CONFIG_NO_CLASS_INVARIANTS_ON_FUNCTION_ENTRY, that would disable invariant checking before function or destructor call, but still check them after function or constructor call? (10) It looks that when I include header <contract/class.hpp>, I also include <boost/concept/requires.hpp> even if I do not intend to use concepts. Would it be possible to avoid this somehow? (An additional header that also allows me to use macros: like CONTRACT_FUNCTION, but does not include <contract/class.hpp>, and if I use keyword "requires" the compilation fails). (11) The library supports almost all of C++03's declaration syntax, but I suppose it may not support some essential declarations from C++11, e.g.: noexcept(condition) or trailing return types. I hope it is doable in the future? (12) In the documentation (Introduction) we read that "This library is implemented for the C++03 <http://en.wikipedia.org/wiki/C%2B%2B> standard and it does not require C++11 <http://en.wikipedia.org/wiki/C%2B%2B11>." I think it is a bit imprecise, because many examples in the docs silently assume that variadic macros, which are not part of C++03, are available. I believe something like this would be more accurate "This library is designed to work on C++03 compilers that support variadic macros; no other C++11 support is necessary. Additionally, if variadic macros are not supported, this library works in >>strict C++03<< mode with slightly different syntax." (13) The documentation says that you can use protected and private members in contracts because "C++ provides programmers ways around access level restrictions (e.g., friend and function pointers)". Next, we read that "only public member functions shall check class invariants. Private and protected member functions are allowed to brake class invariants because private and protected member are part of the class implementation and not of its specification". To me, these two statements appear incompatible: either we say that only public members constitute class'es interface, or even protected and private members constitute class interface, e.g. for befriended functions. And either we both contract-check only public functions and allow only public members in contracts, or we both contract-check all functions and allow all members in contract. I prefer the former. Or am I missing something? If there are some technical obstacles in checking member access in assertions, then I accept such library limitation, but the current argumentation in the docs appears inconsistent. (14) The docs say that in order to make disabling of nested assertions thread-safe in multi-threaded programs, the library needs to use a global lock. Sorry if I am talking nonsense now (I have no intuition of using DbC in multi-threaded apps), but is it not possible to use thread_local storage for this purpose? Is it possible that executing an assertion in one thread would cause the execution of another (nested) assertion in another thread? (15) Unfortunately, I will not have time to check it, so I will only ask you: are any special considerations required in contract-checking classes that inherit virtually (e.g. class hierarchies with diamond inheritance structure). Order of object layout and construction is very particular in those classes, perhaps the order of contract verification and subcontracting should be special a well? (16) Functions like set_precondition_broken() are defined with dynamic exception specification: throw(). Is this necessary? throw() is known to be causing problems, adds little value, and some compilers do not support it; some other issue warnings on dynamic exception specifications; and they are deprecated. (17) According to docs, the framework checks invariants on destructor throw. This is already tracked: https://sourceforge.net/apps/trac/contractpp/ticket/66 (18) "Duplicated globals" problem may cause failure to register custom contract failure handler. This is already tracked: https://sourceforge.net/apps/trac/contractpp/ticket/60 (19) Documentation sometimes uses name "Contract Programming" as though it was a framework. For instance, "This library implements Contract Programming" or "Contract Programing checks them". I think it is incorrect. I understand that "Contract Programming" is a philosophy or a paradigm, whereas what you mean should be called "Contract Programming Framework" or similar. (20) In "Contract Programming Overview" -> "Benefits", in the note we read, "However, the probability that programmers make a mistake twice (in both the body *and* the contract) is lower than the probability that the mistake is made just once (in either the body or the contract)". This implies that we write contracts in order that the code be duplicated because this reduces the probability of the bug. I believe that the mechanism of testing in general is somewhat different (contract-checking is similar to unit testing in this respect, I think): you want the tests to be much simpler then the code they test. Therefore when some test fails you know (although not for sure) that it is the code that is broken rather than the test. For instance: double sqrt(double v) postcondition{ close(return * return = v); }; Testing almost the same thing as function body makes sense because multiplication is conceptually much simpler than the logic to find the square root. Conversely, writing this: bool invert(bool b) postcondition{ b == !return; }; Would be of little practical value, and I believe if there is a chance I will implement such function incorrectly, duplicating the logic in the precondition does not in practice reduce by half the probability of leaving the bug in the code. (21) Contract failure handlers will likely be customized inside function main(). This means that it will be difficult (although not impossible) to customize these actions for contracts of constructors of global objects. This is a very small problem and N1962 also seems to suffer from it and in fact even C++ suffers from it, when it comes to installing terminate handler with set_terminate. (22) Some random type-os in the docs. (apologies that I bluntly paste my notes without editing them, but I am too tired to do it): * " In addition, the library implements" -- don't mention it in the first sentence. * " and increasing overall software quality" -- no meaning * "trailing column symbol :" -> "trailing colon symbol :" * "First, the class invariants and the function preconditions are checked." -> "First, the class invariants are checked, then the function preconditions are checked. "(split it) * "Differences with C++ Syntax" -> "differences from"?<http://contractpp.svn.sourceforge.net/viewvc/contractpp/releases/contractpp…> * "postconditions and class invariants cannot be weaken. " -> weakened * "This library implement this feature however" -> "This library implements this feature, however" * "A *free function* [8<http://contractpp.svn.sourceforge.net/viewvc/contractpp/releases/contractpp…> ] call executes the following steps: " -- mention throw * "Preconditions cannot access the object" -- "you shouldn't" or "it is not possible"? * "to ontract" in destructor tutorial === STANDARD REVIEW QUESTIONS === * What is your evaluation of the design? * What is your evaluation of the implementation? Unfortunately, the macro tricks are beyond my mental powers, so I am unable to evaluate the design and implementation. I could only try to break it or test if it behaves as documented on examples. I can see that the framework is customizable (broken contract handlers, disabling the compilation of handlers). One design flaw I can see is that it is a header-only library while it requires some globals to store the handlers. But this is already recorded as a confirmed bug: http://sourceforge.net/apps/trac/contractpp/ticket/60 * What is your evaluation of the documentation? Very, very good: easy intro for the beginners, very detailed, describes not only the library but also the problem domain, lots of examples. * What is your evaluation of the potential usefulness of the library? It may be disqualified from production code by many parties due to the unusual syntax. But it is definitely useful for learning DbC, experiments, personal projects (where you need not convince others to use the interface they do not like) * Did you try to use the library? With what compiler? Did you have any problems? * How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? I played with the library for three evenings, running basic tests and trying to break it. I read the documentation. I also had some conversations with Lorenzo as he was developing the library, and reviewed previous versions of the docs. I am using VisualStudio 2010. * Are you knowledgeable about the problem domain? I know Contract Programming from Meyer's book and ISO C++ proposals (N1613, N1669, N1773, N1866, N1962) and Lorenzo's documentation. I haven't used it in practice on a dig scale. === FINALLY === The work Lorenzo did for this library is incredible. He already contributed to the knowledge of the limits and the power of the preprocessor. Supporting contracts in C++ without language extensions appeared (at least to me) impossible. It is a great piece of work. Regards, &rzej

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[Review] Boost.Contract Review Period Extended
by Dave Abrahams 06 Sep '12

06 Sep '12

We've had lots of good discussion, and gotten three votes so far, but for a library of this scope I would like to see more. Therefore, we're extending the review period through Sept 7th. Please take the time to look at it, and *please vote for or against acceptance*. As noted below, everyone who looks at the library is qualified to vote, and every vote is valuable. Thanks, Dave ,----[ Important Notes ] | - Please post your review to the Boost Developers' list | (http://lists.boost.org/mailman/listinfo.cgi/boost) | - Please begin your review's subject line with "[Review:Contract]" | - Please do not post your review or discussion as a reply to this | message. | - Please feel free to note any individual issues in the issue | tracker at https://sourceforge.net/apps/trac/contractpp/report/3 | (you'll need to log in at Sourceforge to add a ticket) and make | reference to them from your review. | - Please see below for *further* important notes `---- THE LIBRARY Boost.Contract implements Contract Programming (a.k.a., Design by Contracts) for C++. In addition, the library implements virtual specifiers, concept checking, and named parameters. Documentation: http://contractpp.sourceforge.net Source: http://sourceforge.net/projects/contractpp/files/latest/download All N1962 requirements and Eiffel features are supported by the library, among others: 1) Support for preconditions, postconditions, class invariants, block invariants, and loop variants. 2) Subcontract derived classes (with support for pure virtual functions and multiple inheritance). 3) Access expression old values and function return value in postconditions. 4) Optional compilation and checking of preconditions, postconditions, class invariants, block invariants, and loop variants. 5) Customizable actions on contract assertion failure (terminate by default but it can throw, exit, etc). This library is implemented for C++03 and it does not require C++11. Obviously, if the library is accepted, all macros will be prefixed by BOOST_... and other symbols will go under the boost::... namespace. Potential Interactions with Existing Boost Libraries ==================================================== This submission potentially interacts with the following existing Boost libraries: * parameter - http://boost.org/libs/parameter * static_assert - http://www.boost.org/libs/static_assert * MPL - http://www.boost.org/libs/mpl * Concept - http://www.boost.org/libs/concept_check Reviewers should consider these potential interactions. What to include in Review Comments ================================== - Keep your criticism constructive. Constructive criticism usually comes with specific suggestions for improvement. - If you identify problems along the way, please note if they are minor, serious, or showstoppers. - Please *do* vote on whether the library should be accepted. Everyone who takes the time to look at the library is qualified to vote, and every vote is valuable. - Other questions you might want to answer in your review: * What is your evaluation of the design? * What is your evaluation of the implementation? * What is your evaluation of the documentation? * What is your evaluation of the potential usefulness of the library? * Did you try to use the library? With what compiler? Did you have any problems? * How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? * Are you knowledgeable about the problem domain? -- Dave Abrahams BoostPro Computing Software Development Training http://www.boostpro.com Clang/LLVM/EDG Compilers C++ Boost

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[asio]New feature: timeout for poll()
by Max Che 06 Sep '12

06 Sep '12

Hello. I want to use win_iocp_io_service::poll() with timeout. poll() + timeout = poll() functional and free waitable timer! GetQueuedCompletionStatus() (and epoll(), kqueue()) allows to use that. Somebody can add this feature?

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[rational] Over/underflow checked update ready for comments
by Dan Searles 06 Sep '12

06 Sep '12

>> For those interested in the rational number class, see: >> https://svn.boost.org/svn/boost/sandbox/rational >> >> Requesting comments on the code, and review for >> inclusion in the next release. >> >> > >Hi, > >the enum type could follow the one defined in >http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2012/n3352.html >"When an overflow does occur, the desirable behavior depends on the >application, so programmers may specify the overflow mode with a value >of type |enum class overflow|. The possible values are: > >|impossible| > Programmer analysis of the program has determined that overflow > cannot occur. Uses of this mode should be accompanied by an argument > supporting the conclusion. >|undefined| > Programmers are willing to accept undefined behavior in the event of > an overflow. >|modulus| > The assigned value is the dynamic value mod the range of the > variable. This mode makes sense only with unsigned numbers. It is > useful for angular measures. >|saturate| > If the dynamic value exceeds the range of the variable, assign the > nearest representable value. >|exception| > If the dynamic value exceeds the range of the variable, throw an > exception of type |std::overflow_error|. 'impossible' and 'undefined' are effectively the same thing, and equivalent to the 'no check' currently implemented. 'modulus' makes more sense for the fixed point class that it's being described for than rational numbers. I'm not sure a useful definition can even be made for rationals. 'Saturate' sounds like it might be useful, but gets problematic quickly when there is under/overflow within the largest/smallest range limits. The point is that if a result of a calculation is not exactly representable, you will get an exception to notify you. And of course 'exception' is in the new implementation for just that purpose. > >BTW, I have no access to the link for the examples and the test. I have not changed those files. The existing examples and test are still valid for the original non-checked case. For the checked case, I have tests which run for hours. The tests for rational instantiated with signed char is exhaustive (there are only so many normalized values. Pairing up each value with every other value on the binary operators doesn't result in much more that 2**32 combinations). For short/int/long long, sets of interesting values are created, and each value is paired up with every other value in the set. I can provide the test drivers if anyone is interested. > >Could you update the History section? The history section is missing about 6 earlier updates. It also has the problem that it's written in the 1st person by the original author. It might be best to leave that section alone, and just update the main doc body and the revision history of the header file (already done). > >In order to avoid breaking the existing interface, you could define a >class basic_rational that has the new template and define the current >rational using this basic_rational. > >template <typename Integer, overflow Ov> class basic_rational; > >template <typename Integer> class rational : >basic_rational<Integer,overflow::undefined> {...} The new implementation doesn't break the existing interface of the original rational class/header. > >Best, >Vicente Thanks > >P.S A link to a standard proposal >* http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2012/n3363.html. There are some interesting things in there to consider... My current goal, however, is to add over/underflow checking to the original implementation, rather than add new capabilities beyond that. Comments?

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[coroutine] new location
by Oliver Kowalke 05 Sep '12

05 Sep '12

Hi, because some of the community members have had some problems to access the archive I've uploaded the library to a new location. docu: http://ok73.ok.funpic.de/boost/libs/coroutine/doc/html/ src: http://ok73.ok.funpic.de/boost.coroutine.zip I'd like to remember that the review starts at September 3, 2012. The library contains one example using boost.asio together with a stream reading from a socket (without blocking the application if newline was not received). regards, Oliver

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[context] Why does boost::ctx::minimum_stacksize() on Windows return 65536
by Hartmut Kaiser 05 Sep '12

05 Sep '12

Hey all, Why is the minimally possible stack size in Boost.Context on Windows set to be 64k? This seems to be way too high for applications where only a minimal amount of stack is required. I assume, that since Boost.Context allocates the stack using VirtualAlloc the minimum possible value should be equal to the page size (see http://msdn.microsoft.com/en-us/library/windows/desktop/aa366887(v=vs.85).as px). Regards Hartmut --------------- http://boost-spirit.com http://stellar.cct.lsu.edu

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Mail moderated?
by Klaim - Joël Lamotte 05 Sep '12

05 Sep '12

Hi I sent an email to this list this morning that apparently got into moderation because it contained some text files with logs. I'm just not sure it's been noticed by moderators, as it might have been marked spam or something? Joel Lamotte

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Re: [boost] [Review.Coroutine] Some comments
by Oliver Kowalke 05 Sep '12

05 Sep '12

> * I don't know if showing the signature in the documentation will be > more informative. OK > * Could you add the following noexcept specifier? OK > * As the template class Allocator is not used to allocate internal > memory of the coroutine class. Could the Allocator parameter be renamed > StackAllocator? OK > * Could you add an standard Allocator parameter as e.g. the one of > packaged_task? > > C++ International Standard > > * I understand that the Boost.Context Allocator parameter is part od the > class, as context is a low-level class, but coroutine is more high > level. Is there a possibility to type erase the StackAllocator (and > preceding Allocator) template parameter, as packaged_task do? This will > allow to store coroutines (and generators) with the same signature in a > container even if they don't share the Allocator. You mean coroutine would have two allocators - one for allocating internal memory and one for allocating the stack? Removing the StackAllocator from the template arguments of coroutine should not that problem (would require an internal pointer to an internal interface - maybe detail::context_exec is a candidate). I've some concerns about having two allocator objects in coroutine's ctor . > * Parameters and move semantics. Could the signature parameters be > rvalue references? > > R operator()(A0 a0, ..., A9 a9); Hmmm - this would require a second version of opertor() and all arguments are moveable?! R operator()(BOOST_RV_REF( A0) a0, ..., BOOST_RV_REF( A)) a9); > I'm asking this because I think that Boost.Tuple has not implemented yet > move semantics. don't know - would that be an issue > * What about moving some of the coroutine/generator optional parameters > to a coro::attributes class > > std::size_t size = ctx::default_stacksize(), > flag_unwind_t do_unwind = stack_unwind, > bool preserve_fpu = true, instead of passing those threee params as args to coroutine ctor? good point > * Usually (at least in the C++ standard) a function doesn't throws > because of its preconditions are not satisfied. then assert? pre-conditions should be checked but how should I react if I get garbage from the user? > This should be coherent with > > > |Result operator()()| > > Preconditions: > > |*this| is not a /not-a-generator/, |! is_complete()|. > > which doesn't throws any specific exception if the preconditions are not > satisfied. does an assert - OK the I'll replace throwing excpetions be assertions > Documentation > ========= > > coroutine.html > > s/it can migrated between threads/it can migrate between threads/ OK > s/yield_return/yield_break/ > > * documentation for the following constructor is missing in the reference > > template< typename Fn > > coroutine( Fn && fn, > std::size_t size = ctx::default_stacksize(), > flag_unwind_t do_unwind = stack_unwind, > bool preserve_fpu = true, > Allocator alloc = Allocator() ); OK I think it will be easy to incorporate your suggestions - but during the boost.context review I was told not to modify the reviewd library (if the review is still on-going). regards, Oliver

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[rational] Over/underflow checked update ready for comments
by Dan Searles 05 Sep '12

05 Sep '12

>>> Quick overview of the update: the original usage and >>> code of the template class remains mostly as before, ie >>> boost::rational<int> RationalVar; should work as >>> in the original version. Adding 'true' as a second >>> template parameter, however, allows an exception to >>> be raised if an operation with a class variable results >>> in a value that can't accurately be represented >>I haven't looked at anything else, but I dislike using true/false as the template argument. I'd prefer meaningful names. _____ >>Rob Stewart robert.stewart(a)sig.com >>Software Engineer using std::disclaimer; >>Dev Tools & Components >>Susquehanna International Group, LLP http://www.sig.com >Replaced the bool template parameter with an enum: >enum RationalChecktype {RationalNoChecking, RationalCheckforOverflow}; For those interested in the rational number class, see: https://svn.boost.org/svn/boost/sandbox/rational Requesting comments on the code, and review for inclusion in the next release. Dan Searles

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very simple implementation of Andrei Alexandrescu's ScopeGuard idiom
by Sergey Radionov 04 Sep '12

04 Sep '12

https://github.com/RSATom/finally_execute/blob/master/finally_execute.h based on http://www.drdobbs.com/cpp/generic-change-the-way-you-write-excepti/1844037… I know about http://sourceforge.net/projects/loki-lib/ but with boost::bind this can be much simpler: https://github.com/RSATom/finally_execute/blob/master/README I've used this in many of my projects, and found it very usefull.... don't understand, why this simple solution does not contributed already to Boost by someone else... :)

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[graph] property_value no longer valid for bgl_named_parameters
by Alex Hagen-Zanker 04 Sep '12

04 Sep '12

The transition from Boost 1.49 to 1.51 gave me a breaking change in the graph library: Originally I used the property_value struct to get the type of a named parameter, like this: property_value<bgl_params, Tag>::type; This no longer works and the current use seems to be: get_param_type<Tag, bgl_params>::type; Is this a regression? Or was I just using the library in the wrong way? Thanks, Alex

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Enum Conversion
by Roland Bock 04 Sep '12

04 Sep '12

Hi, In a lot of projects in the company I work for we use Ice middleware which allows to define nice interfaces for services. The IDL also allows to define enums, but I cannot set specific values for the enum items. We also need to store some of these values in databases. We use int to represent the enumerations. Since we might feel the need to add more items to an enum or delete an unused one, we cannot just cast enum to int and vice versa when writing to or reading from the database. We need methods that translate enum to int and back in a stable way that won't change for an individual enum item, even if its position in the enum changes. I found a way to do this, which provides enum<->int and enum<->string. It is used like this: typedef enum { Alpha, Beta, Gamma, Delta, Epsilon } Greek; CREATE_CONVERTER_METHODS(Greek, (Alpha, 5), (Beta, 3), (Gamma, 7), (Delta, 1), (Epsilon, 6)); std::cout << GreekToString(IntToGreek(1)) << std::endl; std::cout << GreekToString(IntToGreek(6)) << std::endl; std::cout << GreekToInt(Alpha) << std::endl; std::cout << GreekToString(Alpha) << std::endl; std::cout << IntToGreek(17) << std::endl; ------ $ ./a.out Delta Epsilon 5 Alpha terminate called after throwing an instance of 'std::invalid_argument' what(): unexpected Greek value My questions are: a) Is this something that might be interesting for others as well? (Or does boost even offer something like that already?) b) I'd really like to be able to write this instead: CREATE_CONVERTER_METHODS(Greek, Alpha = 5, Beta = 3, Gamma = 7, Delta = 1, Epsilon = 6); Obviously, if I could use the preprocessor to translate Alpha = 5 -> (Alpha, 5) I'd be done. But I have no idea how to do that. Any suggestions? Thanks and regards, Roland

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[Contract] noexcept and custom contract violation handlers
by Andrzej Krzemienski 04 Sep '12

04 Sep '12

Hi, I have just realized that there is an interesting interaction between "noexcept" and Contract Programming framework. Not only Lorenzo's library, but even if contracts were a language feature. N3248 ("noexcept prevents library validation", http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2011/n3248.pdf) recommends that functions with any preconditions should not be declared noexcept(true) in case someone wants to report precondition failures via exceptions. If preconditions become part of declaration syntax, declaring both precondition and noexcept(true) could (and should?) be recognized as compile-time error. But now also invariants and postconditions come into play: if a function declares a postcondition, or our class defines an invariant, should we be allowed to declare our function noexcept? What if someone wants to report an invariant or postcondition failure via special exception? (I do not have a good answer for it.) Regards, &rzej

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[contract] invariant checking after destructor throw
by Andrzej Krzemienski 04 Sep '12

04 Sep '12

I have found a potential issue while reading the documentation. (The documentation is very good BTW). It says that the non-static invariant is still checked if object's destructor throws an exception. Am I reading it right? If so, I believe this is not correct. I have two problems with it: 1. According to the standard, an object is considered destroyed (its life-time has ended) when its destructor *starts*. Even if it throws an exception, it is considered destroyed, so accessing its members (in order to check for the invariant) may be illegal (an undefined behavior). 2. Why such an object (that threw on destruction) would need to preserve the invariant? You cannot access it or use it or even destroy it the second time, because it has already been destroyed. No-one will notice it anyway. Or am I missing something? Regards, &rzej

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[Review:Contract] Late review
by Steven Watanabe 03 Sep '12

03 Sep '12

AMDG First of all, *Yes, Contract should be accepted into Boost* I've only really looked at part of the documentation so far. Here's my comments from that. I may have more later depending on how much time I have. index.html: - "Contract Programming (CP) allows to specify" Use a gerund (specifying) instead of an infinitive. An infinitive here needs a subject. - "... allowing to find bugs ..." Same problem, although it can't be fixed in the same way, since the participle + gerund would sound awkward. It could be handled with a passive infinitive. (allowing bugs to be found) - "and it was first introduced by the Eiffel programming language " You can leave out the "it." It sounds awkward to me. - "Eiffel programming language" Using this repeatedly sounds a bit pedantic. You can just say "Eiffel" after the first occurance. - The side by side code in the example gets a bit wide. This will definitely be a problem if you want the documentation to be generated as a PDF. - I don't understand why the library needs to deal with access control. Why can't the user just use public: private: protected: as usual? - CONTRACT_OLDOF kind of sticks out at me. I don't really like the way it looks having it a macro when everything else is keywords that are parsed by the top level macros. - "...if there is a bug in the function caller for which push_back is called when size is equal to max_size ..." This clause is somewhat confusing. - "...with the assertion number to uniquely identity..." s/identity/identify/. Also don't split infinitives. - "This library suffers of two limitations" s/of/from/ getting_started.html: - "This section explains how to setup..." "set up" should be two words. "setup" as one word is a noun. - "... failure of the checked condition does not abort the program, instead ..." Run on sentence. - "The implementation of this library uses..., templates with partial specializations and function pointers (similarly to Boost.Function), ..." I don't understand the connection between partial specialization and function pointers. Why are they grouped together? contract_programming_overview.html: - "It is assumed that programmes" s/programmes/programmers/ - "...to formally program specifications". Don't split the infinitive. "to program specifications formally" - "Then, this library aims to be ..." "Then" doesn't sound right here. "Then" is usually used for conditions ("if... then") or sequences (e.g. First.... Then...), but there's nothing for it to connect to here. - "Contract Programming is characterized by the following type of assertion mechanisms." s/type/types/ - "before the body execution." I think it would sound better to use the possesive "body's execution" or "execution of the body". rather than apposition. - "Preconditions cannot be strengthen, postconditions and class invariants cannot be weaken. " s/strengthen/strengthened/, s/weaken/weakened/ - I'm not sure that I would consider Subcontracting to be an assertion mechanism. - "Block Invariants | These are logical conditions that programmers except ..." s/except/expect/ - "...while a contract assertions is ..." s/assertions/assertion/ - "This library implement this feature however it should be noted ..." Run on sentence. - "protect such a global variable from racing conditions " It's called a "race condition." - "but that will effectively introduce a global lock in the program" This seems like a classic use case for thread specific storage. - "Furhtermore," s/Furhtermore/Furthermore/ - "Contracts are part of the source code, they are..." Run on sentence (comma splice) - "detailed error messages that greatly helps debugging" "helps" needs to agree with "messages." - "Contract Programming benefits come to the cost of performance " "to" is the wrong preposition. Try "at." - "The run-time performances are negatively ..." "performance" should be singular. Plural doesn't really make sense for abstract nouns like this. - "1. The extra processing required to check the assertions. 2. The extra processing required by the additional function calls (additional functions are invoked to check preconditions, postconditions, class invariants, etc)." How is (2) different from (1)? - "checking function arguments using postconditions " I think you mean /pre/conditions. - "so that these initializations can relay" s/relay/rely/ - "C++ object construction mechanism ..." You need an article. "The C++..." - "Check the non-static class invariants, but only if the body threw an exception." This could use a rationale. Destructors are generally not supposed to throw at all. - "Contracts are only responsible to check the " "for checking" instead of "to check." - "...to only use public members, Eiffel instead ..." Split infinitive, run-on sentence. - "...are allowed to brake class invariants..." s/brake/break/ - "Arbitrary code in contracts | No, assertions only." This is a bit misleading, since assertions can execute arbitrary code. tutorial.html: - "complete guide on this library syntax" s/library/library's/ - result == oldof valule s/valule/value/ - "int const" IIRC, you can't have a const rvalue of a built-in type. - "parameter names can instead by omitted " s/by/be/ - params_postinc You didn't update the pre/post conditions when you copied this from the last example. - "Function and array types cannot be directly used as function parameter types within the contract macros but extra typedef declarations can be used to workaround this limitation " This workaround doesn't work in function templates where the array element or dimension is deduced. - "the maximum number of supported array dimensions is specified by the CONTRACT_CONFIG_ARRAY_DIMENSION_MAX macro" I don't understand the reason for this limitation. - "...evaluates all contract conditions in constant-correct context" Add an article "a" before "const-correct." - "the type of value type" Delete the second "type." - ConstantCopyConstructible You're definitition of CopyConstructible is wrong. A type that only defines T(T&) is not CopyConstructible. - "However, it is still necessary to ontract" s/ontract/contract/ - unique_identifiers I think it's worth pointing out that the postcondition can't assume that the precondition was true in the face of subcontracting. I did a double take when I saw old_found. - "Wakened inherited preconditions ..." s/Wakened/Weakened/ oldof.hpp: The definition of CONCEPT_OLDOF is a bit dangerous. It can't safely be passed as a macro argument. What do you think of this bit of PP magic: #define TEST_EXPAND_EXPAND_OLDOF(x) CONTRACT_OLDOF #define TEST_EXPAND_NOTHING(x) oldof #define TEST_EXPAND_I(x) TEST_EXPAND_ ## x #define TEST_EXPAND(x) TEST_EXPAND_I(x) #define oldof TEST_EXPAND(EXPAND_OLDOF(NOTHING(z))) #define EXPAND_OLDOF(expr) expr oldof -> expands to itself EXPAND_OLDOF(random text oldof more random text) -> expands to random text CONTRACT_OLDOF more random text General: - Are ellipsis parameters allowed? - Just say "parentheses," not "round parentheses." Parentheses without any qualification always means (). In Christ, Steven Watanabe

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mpi compile bug
by 陈立红 03 Sep '12

03 Sep '12

Hi guys, I have installed the OpenMPI_v1.6.1 and want to make use of boost mpi. But I cannot compile it with msvc10.0 successfully. The error message is like below. I found similar bug Ticket #5465 (new Bugs), but there's no one comment on it. Please help. E:\soft\boost_1_49_0>bjam stage --toolset=msvc-9.0 --with-mpi --stagedir="E:\sof t\boost_1_49_0\Debug\lib10" link=static runtime-link=shared runtime-link=static ָ��줿�ѥ��Ҋ�Ĥ��ޤ�� ָ��줿�ѥ��Ҋ�Ĥ��ޤ�� ָ��줿�ѥ��Ҋ�Ĥ��ޤ�� ָ��줿�ѥ��Ҋ�Ĥ��ޤ�� MPI auto-detection failed: unknown wrapper compiler mpic++ Please report this error to the Boost mailing list: http://www.boost.org You will need to manually configure MPI support. warning: skipping optional Message Passing Interface (MPI) library. note: to enable MPI support, add "using mpi ;" to user-config.jam. note: to suppress this message, pass "--without-mpi" to bjam. note: otherwise, you can safely ignore this message. Component configuration: - chrono : not building - date_time : not building - exception : not building - filesystem : not building - graph : not building - graph_parallel : not building - iostreams : not building - locale : not building - math : not building - mpi : building - program_options : not building - python : not building - random : not building - regex : not building - serialization : not building - signals : not building - system : not building - test : not building - thread : not building - timer : not building - wave : not building ...found 1 target... Regards, Lihong Chen

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[trac] Library components: ATTENTION LIBRARY AUTHORS
by Rene Rivera 03 Sep '12

03 Sep '12

If you are the author of an accepted library please remember to ask to add the library to the trac bug system. It's important that others have a component to assign to bugs. In order to add the library component we need to know the trac *account* name you are using. Please check in trac to see if your library has a component (with this report <https://svn.boost.org/trac/boost/report/15>). If not, or if there are errors, please reply here with the new, or corrected, information. And if you don't happen to have a trac account please ask for one (<https://svn.boost.org/trac/boost/wiki#GettingaTracSVNUserid>). Thank you. -- -- Grafik - Don't Assume Anything -- Redshift Software, Inc. - http://redshift-software.com -- rrivera/acm.org (msn) - grafik/redshift-software.com -- 102708583/icq - grafikrobot/aim,yahoo,skype,efnet,gmail

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[lockfree] Faulty (?) static assert
by Hartmut Kaiser 03 Sep '12

03 Sep '12

Hey, The lockfree::queue constructors raise a static assert if no capacity is specified. This contradicts the member initialization code close to the assert, for instance: queue(void): head_(tagged_node_handle(0, 0)), tail_(tagged_node_handle(0, 0)), pool(node_allocator(), has_capacity ? capacity : 0) { BOOST_STATIC_ASSERT(has_capacity); initialize(); } which implies that 'has_capacity' is allowed to be false. From what I can see 'has_capacity' could be false, indeed, in particular if the queue is not bounded in size. Would changing this to queue(void): head_(tagged_node_handle(0, 0)), tail_(tagged_node_handle(0, 0)), pool(node_allocator(), has_capacity ? capacity : 0) { BOOST_STATIC_ASSERT(has_capacity || capacity); initialize(); } reflect the actual intention? Regards Hartmut --------------- http://boost-spirit.com http://stellar.cct.lsu.edu

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[lockfree] Type conversion warnings
by Hartmut Kaiser 03 Sep '12

03 Sep '12

Hey all, The attached patch fixes a couple of warnings about possible loss of precision caused by integral type conversions for MSVC. Ok to commit? Regards Hartmut --------------- http://boost-spirit.com http://stellar.cct.lsu.edu

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[lockfree] freelist_stack::allocate and freelist_stack::deallocate should not be private
by Hartmut Kaiser 03 Sep '12

03 Sep '12

Hey all, Currently, the allocate/deallocate functions et.al. in lockfree::detail::freelist_stack are private. This inhibits reusing this class for implementing other lock-free datastructures as it's not possible to allocate anything which has not a constructor taking 0, 1, or 2 arguments (those are supported explicitly by exposing overloads for freelist_stack::construct). Would it be possible to make the mentioned functions 'protected' instead? Regards Hartmut --------------- http://boost-spirit.com http://stellar.cct.lsu.edu

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Please create a category for atomic, context, and lockfree in trac
by Hartmut Kaiser 02 Sep '12

02 Sep '12

Please create a category for atomic, context, and lockfree in trac. Thanks! Regards Hartmut --------------- http://boost-spirit.com http://stellar.cct.lsu.edu

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[Review:Contract] Some questions
by Vicente J. Botet Escriba 02 Sep '12

02 Sep '12

Hi, First of all, thanks Lorenzo for your work on pre-processor programming. With this library, you have showed to me how far the pre-processing can go in terms of expressiveness. I have some questions before doing a complete the review: = C++11 compatibility = * Does the library use c++11 features when available? I was thinking e.g. on the emulated virtual specifiers. BTW, I think the "new" virtual specifier was removed from the standard, but maybe I'm wrong. * I think the library don't allow to declare C++11 specific classes/function. E.g * variadic templates * noexcept functions * constexpr functions * class/function attributes BTW, I have not see any example using exception specifications using 'throws'. Does the library support them? Could you confirm? and if not, could you tell us if you have a plan to support them? = Postconditions result = "Postconditions can access the function return value by declaring a variable of type |auto| and assigning it to the |return| keyword (the variable name is arbitrary but |result| is often used)." What prevent the library to the use of return instead of an auto variable postcondition( // Postconditions. auto old_value = CONTRACT_OLDOF value, // Old value(s). value == old_value + 1, // Assertion(s)... return == old_value ) instead of postcondition( // Postconditions. auto result = return, // Result value. auto old_value = CONTRACT_OLDOF value, // Old value(s). value == old_value + 1, // Assertion(s)... result == old_value ) =Constant assertions = I would expect that the old are always const so the following postcondition( auto old_even = CONTRACT_OLDOF even, auto old_odd = CONTRACT_OLDOF odd, // `[old_]even` and `[old_]odd` all `const&` within assertions. const( even, old_even ) even == old_even + 2, const( odd, old_odd ) odd == old_odd + 2 ) should be rewritten without loss of semantics as postcondition( auto old_even = CONTRACT_OLDOF even, auto old_odd = CONTRACT_OLDOF odd, // `[old_]even` and `[old_]odd` all `const&` within assertions. const( even ) even == old_even + 2, const( odd ) odd == old_odd + 2 ) = Oldof = As the old of value must be declared using a variable, using a specif oldof keyword that will replace auto old_size = CONTRACT_OLDOF size(), by oldofold_size = size(), could simplify the syntax. What do you think? Some minor points: * Why do you use( void ) instead of () in the functions without parameters? e.g. public: bool empty ( void ) const { return vector_.empty(); } Some suggestions: * Use 2 spaces indentation instead of 4 could reduce the width of the page, in particular when you use several columns. * The use of'int const' as return type is verbose and could be replaced by just int. Best, Vicente

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[context] Recent changes (rev. 80363) break compilation
by Hartmut Kaiser 02 Sep '12

02 Sep '12

Hey all, The latest commit to trunk (rev. 80363) breaks compilation of Boost.Context on Windows. I'm attaching a patch fixing the issue. Ok to commit? Regards Hartmut --------------- http://boost-spirit.com http://stellar.cct.lsu.edu

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[Review:Contract] Base class preconditions not checked
by Steven Watanabe 02 Sep '12

02 Sep '12

AMDG Test case attached. The problem is that the precondition test is executed when initializing a virtual base. Virtual bases are always initialized by the most derived class, so the preconditions of base class constructors are never checked. In Christ, Steven Watanabe

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[lockfree] Inconsistent typedef tag_t in tagged_ptr
by Hartmut Kaiser 02 Sep '12

02 Sep '12

Hey all, The embedded typedef <...> tag_t has inconsistent visibility in the two implementations of tagged_ptr. In tagged_ptr.hpp this typedef is 'public', while in the file tagged_ptr_ptrcompression.hpp this typedef is 'private'. Would it be possible to make it public in both cases (patch attached)? Regards Hartmut --------------- http://boost-spirit.com http://stellar.cct.lsu.edu

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[context] Windows ctx::maximum_stacksize() runtime asserts
by Hartmut Kaiser 02 Sep '12

02 Sep '12

Hey all, The Windows implementation of boost::ctx::maximum_stacksize() does always assert: std::size_t maximum_stacksize() { BOOST_ASSERT( ! is_stack_unbound() ); static std::size_t stacksize = 8 * 1024 * 1024; return stacksize; } That is because is_stack_unbound() will unconditionally return true. Patch is attached - ok to commit? Regards Hartmut --------------- http://boost-spirit.com http://stellar.cct.lsu.edu

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MPI maintainer?
by Ralf Grosse-Kunstleve 02 Sep '12

02 Sep '12

Who is currently maintaining Boost MPI? We have two trac items I'd like to assign to the MPI maintainer. The first one has been sitting there for a long time already. https://svn.boost.org/trac/boost/ticket/6123 https://svn.boost.org/trac/boost/ticket/7316 Ralf

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[test] Boost.Test unreleased since November 2009 ?
by Mathieu Champlon 02 Sep '12

02 Sep '12

Hi, I've noticed that no merge has been made from trunk to the release branch for Boost.Test since November 2009, meaning that a lot of bug fixes and features have remained unreleased. Is it on purpose ? Thanks, MAT.

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[test] Where should I put replacement functions for WinCE?
by Jan Hudec 02 Sep '12

02 Sep '12

Hello Folks, Windows CE don't have time and clock functions, getenv function and errno.h (though they seem to have _errno function). I needed to define these things to get Boost.Test to build for WinCE. Now it would be nice to have this work by default. I can provide the definitions (they are quite simple), but I am not sure where would be correct place for them. Should I add them to config/platform/win32.hpp, create config/platform/wince.hpp or put them just in test? Thanks, Jan -- Jan 'Bulb' Hudec <bulb(a)ucw.cz>

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[test] sigaltstack does not work on older Android
by Jan Hudec 02 Sep '12

02 Sep '12

Hello Folks, Android NDK contains several "platforms", depending on which release one desires to be compatible with. Boost test compiles fine with android-8 and newer, but the older versions have incomplete definition of sigaltstack (they define the structure, but not the function), causing compilation error in boost/test/detail/impl/execution_monitor.ipp. I have fixed it locally by adjusting the condition for defining BOOST_TEST_USE_ALT_STACK, but I am not sure which level of fix would be best suited for integrating in boost. I see 3 options: 1. Leaving it as is and simply saying android is only supported from API level 8 (that's 2.2; we are still compiling for 2.1 (which has no changes in native since 2.0)) 2. Simply disabling BOOST_TEST_USE_ALT_STACK in Android; it's not necessary after all. 3. Being really precise and reading the API version, but that requires including extra header. It would be nice, but I am not sure what is the correct place to include it. Here is a simple patch that just disables sigaltstack for Android: --- a/boost/test/impl/execution_monitor.ipp +++ b/boost/test/impl/execution_monitor.ipp @@ -173,7 +173,7 @@ namespace { void _set_se_translator( void* ) {} } # endif # endif -# if !defined(__CYGWIN__) && !defined(__QNXNTO__) +# if !defined(__CYGWIN__) && !defined(__QNXNTO__) && !defined(__ANDROID__) # define BOOST_TEST_USE_ALT_STACK # endif And here is a more complex patch that on android (the __ANDROID__ macro is predefined by the compiler in Android NDK) reads the api-level and uses it to decide: --- a/boost/test/impl/execution_monitor.ipp +++ b/boost/test/impl/execution_monitor.ipp @@ -173,7 +173,11 @@ namespace { void _set_se_translator( void* ) {} } # endif # endif -# if !defined(__CYGWIN__) && !defined(__QNXNTO__) +# if defined(__ANDROID__) +# include <android/api-level.h> +# endif + +# if !defined(__CYGWIN__) && !defined(__QNXNTO__) && (!defined(__ANDROID__) || __ANDROID_API__ >= 8) # define BOOST_TEST_USE_ALT_STACK # endif -- Jan 'Bulb' Hudec <bulb(a)ucw.cz>

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[test] Fix WinCE workaround
by Jan Hudec 02 Sep '12

02 Sep '12

Hello Folks, boost/test/impl/execution_monitor.ipp has workaround for older MSVC++ and assumes WinCE version need it too. However the WinCE compiler caught up in next version. Here is a proposed patch: --- a/boost/test/impl/execution_monitor.ipp +++ b/boost/test/impl/execution_monitor.ipp @@ -84,7 +84,7 @@ using std::va_list; typedef unsigned uintptr_t; # endif -# if BOOST_WORKAROUND(_MSC_VER, < 1300 ) || defined(UNDER_CE) +# if BOOST_WORKAROUND(_MSC_VER, < 1300 ) || (defined(UNDER_CE) && BOOST_WORKAROUND(_MSC_VER, < 1500 )) typedef void* uintptr_t; # endif -- Jan 'Bulb' Hudec <bulb(a)ucw.cz>

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[test] Interest in gtest-like output?
by Jared Grubb 02 Sep '12

02 Sep '12

I really like the Boost.Test framework, however, I cant help but have a bit of envy over how great the output from googletest looks. I've been playing around with writing a formatter/outputter that emulates the output style of googletest, and I am willing to spend some time to pretty it up and generate a patch if there's interest. Does anyone think this would be a worthy submission to boost? For an example of what the output looks like, this site has some great examples: http://www.ibm.com/developerworks/aix/library/au-googletestingframework.html (just to clarify: I'm not suggesting changing any BOOST_TEST syntax, just adding a new optional way to format the test progress and results to stdout) Jared

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Re: [boost] [lockfree] Faulty (?) static assert
by Hartmut Kaiser 01 Sep '12

01 Sep '12

> The lockfree::queue constructors raise a static assert if no capacity is > specified. This contradicts the member initialization code close to the > assert, for instance: > > queue(void): > head_(tagged_node_handle(0, 0)), > tail_(tagged_node_handle(0, 0)), > pool(node_allocator(), has_capacity ? capacity : 0) > { > BOOST_STATIC_ASSERT(has_capacity); > initialize(); > } > > which implies that 'has_capacity' is allowed to be false. From what I can > see 'has_capacity' could be false, indeed, in particular if the queue is > not bounded in size. > > Would changing this to > > queue(void): > head_(tagged_node_handle(0, 0)), > tail_(tagged_node_handle(0, 0)), > pool(node_allocator(), has_capacity ? capacity : 0) > { > BOOST_STATIC_ASSERT(has_capacity || capacity); > initialize(); > } > > reflect the actual intention? Sorry, I meant: > BOOST_STATIC_ASSERT(has_capacity || !capacity); Regards Hartmut --------------- http://boost-spirit.com http://stellar.cct.lsu.edu > > Regards Hartmut > --------------- > http://boost-spirit.com > http://stellar.cct.lsu.edu > >

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[atomic] Windows autolinking and longlong patches
by Hartmut Kaiser 01 Sep '12

01 Sep '12

Hey, Please find attached two patches for Boost.Atomic (trunk, rev. 80334) adding auto-linking for MSVC, fixing symbol visibility, and fixing a long long problem. Ok to commit? Regards Hartmut --------------- http://boost-spirit.com http://stellar.cct.lsu.edu

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