February 2013 - Boost - lists.preview.boost.org

[gil] What is the status of the Gil extension numeric?
by Krzysztof Czainski 18 Mar '13

18 Mar '13

Hello, During my first steps wit Boost.Gil I bumped onto an example [1], that uses the numeric extension. For this extension, the the example [1] and a ling from Boost.Gil docs [4] point to [2], where I couldn't find any Gil extensions to download. Most Google links pointed to the same page, but I finally found [3]. So my questions are: a) Is there a plan to add the extension numeric to Boost? b) Is [3] the newest version? And could the Boost.Gil docs be updated to point to the right place? c) I corrected a few bugs in boost/gil/extension/numeric/sampler.hpp -- is this list the right place to discuss modifications to the numeric extension? Regards, Kris [1] http://www.boost.org/doc/libs/1_53_0/libs/gil/example/resize.cpp [2] http://opensource.adobe.com/gil [3] http://code.google.com/p/gil-contributions/ [4] http://www.boost.org/doc/libs/1_53_0/libs/gil/doc/index.html

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Help in setupping regression tests on ARM
by Antony Polukhin 16 Mar '13

16 Mar '13

I've successfully run nests on x86, but on ARM I've got the following message: # Running Boost.Build tests Traceback (most recent call last): File "run.py", line 60, in <module> runner(root) File "/home/pi/boost_maintain/run_trunk/tools_regression_src/regression.py", line 205, in __init__ self.main() File "/home/pi/boost_maintain/run_trunk/tools_regression_src/regression.py", line 566, in main getattr(self,action_m)() File "/home/pi/boost_maintain/run_trunk/tools_regression_src/regression.py", line 531, in command_regression self.command_test() File "/home/pi/boost_maintain/run_trunk/tools_regression_src/regression.py", line 329, in command_test self.command_test_boost_build() File "/home/pi/boost_maintain/run_trunk/tools_regression_src/regression.py", line 369, in command_test_boost_build "boost/bin.v2/libs/any/test/any_test.test")); OSError: [Errno 2] No such file or directory: '/home/pi/boost_maintain/run_trunk/results/boost/bin.v2/libs/any/test/any_test.test' I try to run tests on RaspberryPi, it is armhf. Compilller is GCC-4.6.3, 25Gb of free space on SD card. It looks strange, that I see only a few folders in /home/pi/boost_maintain/run_trunk/results/boost/bin.v2/libs/ (there are only 6 folders) -- Best regards, Antony Polukhin

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[type_traits] Some traits are missing
by Antony Polukhin 15 Mar '13

15 Mar '13

Hi all, Equivalents of following traits are in C++11 Standard, but missing in Boost.TypeTraits library: has_nothrow_move_assign has_nothrow_move_constructor has_trivial_move_assign has_trivial_move_constructor Extremely naive implementation of those functions exist in Boost.Variant, so as a start we can use them. Or am I missing something and there is a reason, why those traits are not included in Boost.TypeTraits? -- Best regards, Antony Polukhin

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

05 Mar '13

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

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[thread] C++11 once_flag enabled when constexpr is not available
by Andrey Semashev 05 Mar '13

05 Mar '13

Hi, Vicente! I see you applied my patch for call_once but you seem to forgot to disable the C++11 call_once interface when the compiler does not support constexpr. Was that intentional or you just missed it? Anyway, please find the patch attached.

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[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

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[thread] barrier::wait() not marked as interruption_point
by Oliver Kowalke 04 Mar '13

04 Mar '13

In the documentation (1.53 beta) barrier::wait() is not marked as interruption-point nor that it will throw thread_interrupted if thread blocked inside barrier::wait() if it gets interrupted. Because barrier::wait() calls condition_variable::wait() and condition_variable::wait() is a interruption-point barrier::wait() should it be too - or do I miss something? Oliver

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[persistent] Library preview: Persistent
by Stefan Strasser 04 Mar '13

04 Mar '13

Hi everyone, I'm thinking about finishing a library that was proposed a couple of years ago. It was pretty far along, and there is documentation available in the sandbox (somewhat outdated): https://svn.boost.org/svn/boost/sandbox/persistent/libs/persistent/doc/html… It is a library with the goal of storing C++ objects on disk, with an interface that is as close as possible to accessing regular C++ objects in memory. A very simple example could look like this: shared_loc<person> p=...; { transaction tx; p->name="..."; p->address="..."; tx.commit(); } It is based on Boost.Serialization, but automatically maintains a consistent state on disk (ACID transactions), which can be updated incrementally. Part of its code was moved to a library named Transact to work alongside other transactional resources (like memory) and is available in the sandbox: https://svn.boost.org/svn/boost/sandbox/transaction/boost/transact/ I'd like to know whether the boost community is still interested in such a library, and I suppose there are quite a few new people here so your comments are welcome as well. Thank You!

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[type traits] is_literal_type ?
by Robert Ramey 02 Mar '13

02 Mar '13

Any chance of a boost implementation for is_literal_type? Robert Ramey

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Git Conversion Schedule
by Sebastian Redl 02 Mar '13

02 Mar '13

Hi, According to the timeline linked from the svn.boost.org frontpage, we're already using Git: https://svn.boost.org/trac/boost/wiki/ModCvtSchedule But I'm pretty sure that's not the case, right? What is the current schedule? Sebastian

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[tweener] How to copy image files in documentation
by Julien Jorge 01 Mar '13

01 Mar '13

Hi, I wrote the documentation of Boost.Tweener in boostbook format. I have references to some images in the documentation but they are not copied in the target html directory when I type bjam html How can I make the image directory to be automatically copied in the target directory of the generated documentation? Since I am not familiar with the build process of Boost yet, I would accept a reason not to do this as an answer :) Regards, Julien Jorge

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[type_erasure] overloading macro
by Christophe Henry 28 Feb '13

28 Feb '13

Hi all, I played a bit more with overloading and it started being annoying and error-prone to add more overloads of concept_map (with more arguments) so I wrote a small macro to 1) generate my overloads and 2) save myself the time reading compiler errors when I use BOOST_TYPE_ERASURE_MEMBER and make a mistake in the number of arguments. It's for C++11 (argument pack) as it's all I need at the moment but I suppose that with Boost.Preprocessor, it'd be for C++03 doable. Well, in case it'd be of any use to someone, here it is, with a small test (tested with g+ 4.5 with -std=c++0x). #include <boost/type_erasure/concept_interface.hpp> #include <boost/type_erasure/rebind_any.hpp> #include <boost/type_erasure/derived.hpp> #include <boost/type_erasure/is_placeholder.hpp> #include <boost/type_erasure/constructible.hpp> #include <boost/type_erasure/relaxed_match.hpp> #include <boost/type_erasure/any.hpp> #include <boost/type_erasure/builtin.hpp> #include <boost/type_erasure/any_cast.hpp> #include <boost/type_erasure/detail/macro.hpp> #include <boost/mpl/vector.hpp> #include <iostream> #ifndef BOOST_NO_CXX11_VARIADIC_TEMPLATES #define BOOST_TYPE_ERASURE_MEMBER_VARIADIC_I(qualname,concept_name,member) \ BOOST_TYPE_ERASURE_OPEN_NAMESPACE(qualname) \ template <typename T, typename... Args> \ struct concept_name{ \ static void apply(const T& t, const Args... a) { t.member(a...); } }; \ BOOST_TYPE_ERASURE_CLOSE_NAMESPACE(qualname) \ namespace boost { namespace type_erasure { \ template<class T, typename... U, class Base, class Enable> \ struct concept_interface< BOOST_TYPE_ERASURE_QUALIFIED_NAME(qualname)<T, U... >, Base, T, Enable> : Base { \ typedef void _fun_defined; \ void member(typename rebind_any<Base, U>::type... arg)const \ {call(BOOST_TYPE_ERASURE_QUALIFIED_NAME(qualname)<T, U...>(), *this, arg...);} }; \ template<class T, typename... U, class Base> \ struct concept_interface< BOOST_TYPE_ERASURE_QUALIFIED_NAME(qualname)<T, U...>, Base, T, typename Base::_fun_defined> : Base{ \ using Base::member; void member(typename rebind_any<Base, U >::type... arg)const \ {call(BOOST_TYPE_ERASURE_QUALIFIED_NAME(qualname)<T, U...>(), *this, arg...);} }; \ }} #endif #define BOOST_TYPE_ERASURE_MEMBER_VARIADIC(qualified_name,member) \ BOOST_TYPE_ERASURE_MEMBER_VARIADIC_I( \ qualified_name, \ BOOST_PP_SEQ_ELEM(BOOST_PP_DEC(BOOST_PP_SEQ_SIZE(qualified_name)), qualified_name), \ member) // supports overloading, does not require any number of arguments BOOST_TYPE_ERASURE_MEMBER_VARIADIC((n1)(n2)(foo),foo) namespace mpl = boost::mpl; using namespace boost::type_erasure; struct Test { void foo()const { std::cout << "foo() called" << std::endl; } void foo(int i)const { std::cout << "foo(int) called with: " << i << std::endl; } void foo(int i,char c)const { std::cout << "foo(int,char) called with: " << i << "," << c << std::endl; } void foo(double d)const { std::cout << "foo(double) called with: " << d << std::endl; } void foo(int i,double d)const { std::cout << "foo(int,double) called with: " << i << "," << d << std::endl; } void foo(int i,double d,char c)const { std::cout << "foo(int,double,char) called with: " << i << "," << d << "," << c << std::endl; } }; int main() { Test t; any< mpl::vector< n1::n2::foo<_self>, n1::n2::foo<_self, int>, n1::n2::foo<_self, double>, n1::n2::foo<_self, int, double>, n1::n2::foo<_self, int, char>, n1::n2::foo<_self, int, double, char>, copy_constructible<> > > x (t); x.foo(); // calls foo() x.foo(1); // calls foo(int) x.foo(1.0); // calls foo(double) x.foo(1,1.0); // calls foo(int, double) x.foo(1,'a'); // calls foo(int, char) x.foo(1,1.0,'a'); // calls foo(int, double,char) return 0; }

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[ptr_container, crc, format] Open tickets - code patches available
by Joachim Faulhaber 28 Feb '13

28 Feb '13

Hi, there are open tickets: https://svn.boost.org/trac/boost/ticket/7430 (ptr_container: warning fixes) https://svn.boost.org/trac/boost/ticket/7433 (crc: runtime check issue) https://svn.boost.org/trac/boost/ticket/7435 (format: crash) that we have submitted 5 months ago. Along with the bug reports there are code patches for the reported issues, that have been tested and used in production code on different platforms. We would kindly ask the maintainers to look at these issues and to apply the patches to the library code, so they can be integrated in the next release. In case the maintainers do not have time to fix these issues within say the next 2 weeks, I (Joachim) would like to ask for permission to apply the patches. Fixing the issues would be very helpful for us, so we don't have to patch the code locally for every new version. Thanks a lot, Joachim & Franz -- Interval Container Library [Boost.Icl] http://www.joachim-faulhaber.de

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Releasing gil::io
by Christian Henning 28 Feb '13

28 Feb '13

Hi all, I have taken a look at the requirements to release a new library. There is some points I like to discuss. Technically speaking gil::io is a replacement of the older gil io extension. So, it's not really a new library. But of course, I don't mind fulfilling all the requirements. Here are the requirements before merging: * root/libs/libraries.htm entry is OK, both in the alphabetic list and in the category lists. Should I add a gil::io entry? * root/libs/maintainers.txt entry is OK. Should I add a gil::io entry? * The library's root/libs/xxx directory contains an index.html file with either the main docs or a redirection to the main docs. Done * The primary docs pages meet Boost requirements and guidelines. Don't leave this until too late; it has turned up lots of issues in the past. I'm using boostbook and the default templates. * Trunk inspection report is clean. I would need some help here to hook up gil::io test with general boost testing. * Trunk regression tests are reasonably clean or marked up. TODO Thanks, Christian

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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

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[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

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[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

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Proposed interface change to boost::algorithm::copy_while
by Marshall Clow 26 Feb '13

26 Feb '13

In 1.50, I introduced: template<typename InputIterator, typename OutputIterator, typename Predicate> OutputIterator copy_while ( InputIterator first, InputIterator last, OutputIterator result, Predicate p ); (and copy_until), which do pretty much what you would expect: copy items from the input to the output as long as the predicate holds. Sean Parent has convinced me that this is wrong; that I have to return the modified input iterator as well. When I wrote these, I was thinking (if I actually was thinking) of actual input iterators, and since they're all the same, so the caller can pick up on the input sequence after the call returns. However, if you're processing (say) a list, it would be kind of useful to know how far in the list the call advanced. I'm proposing to change the interface to: template<typename InputIterator, typename OutputIterator, typename Predicate> std::pair<InputIterator, OutputIterator> copy_while ( InputIterator first, InputIterator last, OutputIterator result, Predicate p ); i.e, changing the return type to return both iterators. What this means: * If you're not calling copy_while (or copy_until), then this change won't affect you. * If you're not using the return value, then this change won't affect you. * If you are using the return value, then you will have to change your code thus: Old foo = copy_while ( first, last, out, p ); New: foo = copy_while ( first, last, out, p ).second; * if you were not using these calls because they didn't return the input iterator, now you can. Questions? Comments? (Except for the "How could you miss that when you wrote those routines?" - I've already asked myself that) Improvements? -- 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

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[context][iostreams] Cygwin Boost 1.53 error building some libraries.
by Mostafa 26 Feb '13

26 Feb '13

On Windows 7, cygwin 2.7, trying to build Boost 1.53 with the following options fails: ./b2.exe --layout=system --variant=release --link=static,shared --threading=single,multi install -j4 with the following errors: gcc.compile.asm bin.v2/libs/context/build/gcc-4.5.3/release/link-static/threading-multi/asm/make_i386_sysv_elf_gas.o libs/context/src/asm/make_i386_sysv_elf_gas.S: Assembler messages: libs/context/src/asm/make_i386_sysv_elf_gas.S:37: Warning: .type pseudo-op used outside of .def/.endef ignored. libs/context/src/asm/make_i386_sysv_elf_gas.S:37: Error: junk at end of line, first unrecognized character is `m' libs/context/src/asm/make_i386_sysv_elf_gas.S:77: Warning: .size pseudo-op used outside of .def/.endef ignored. libs/context/src/asm/make_i386_sysv_elf_gas.S:77: Error: junk at end of line, first unrecognized character is `m' gcc.archive bin.v2/libs/atomic/build/gcc-4.5.3/release/link-static/threading-multi/libboost_atomic.a "g++" -x assembler-with-cpp -O3 -finline-functions -Wno-inline -Wall -DBOOST_ALL_NO_LIB=1 -DNDEBUG -I"." -c -o "bin.v2/libs/context/build/gcc-4.5.3/release/link-static/threading-multi/asm/make_i386_sysv_elf_gas.o" "libs/context/src/asm/make_i386_sysv_elf_gas.S" ...failed gcc.compile.asm bin.v2/libs/context/build/gcc-4.5.3/release/link-static/threading-multi/asm/make_i386_sysv_elf_gas.o... common.copy /home/HPC/boost/v1_53_0/lib/libboost_atomic.a gcc.archive bin.v2/libs/system/build/gcc-4.5.3/release/link-static/threading-multi/libboost_system.a ... common.mkdir bin.v2/libs/date_time/build/gcc-4.5.3/release/link-static gcc.compile.asm bin.v2/libs/context/build/gcc-4.5.3/release/link-static/threading-multi/asm/jump_i386_sysv_elf_gas.o libs/context/src/asm/jump_i386_sysv_elf_gas.S: Assembler messages: libs/context/src/asm/jump_i386_sysv_elf_gas.S:37: Warning: .type pseudo-op used outside of .def/.endef ignored. libs/context/src/asm/jump_i386_sysv_elf_gas.S:37: Error: junk at end of line, first unrecognized character is `j' libs/context/src/asm/jump_i386_sysv_elf_gas.S:72: Warning: .size pseudo-op used outside of .def/.endef ignored. libs/context/src/asm/jump_i386_sysv_elf_gas.S:72: Error: junk at end of line, first unrecognized character is `j' "g++" -x assembler-with-cpp -O3 -finline-functions -Wno-inline -Wall -DBOOST_ALL_NO_LIB=1 -DNDEBUG -I"." -c -o "bin.v2/libs/context/build/gcc-4.5.3/release/link-static/threading-multi/asm/jump_i386_sysv_elf_gas.o" "libs/context/src/asm/jump_i386_sysv_elf_gas.S" ...failed gcc.compile.asm bin.v2/libs/context/build/gcc-4.5.3/release/link-static/threading-multi/asm/jump_i386_sysv_elf_gas.o... ...skipped <pbin.v2/libs/context/build/gcc-4.5.3/release/link-static/threading-multi>libboost_context.a(clean) for lack of <pbin.v2/libs/context/build/gcc-4.5.3/release/link-static/threading-multi>asm/make_i386_sysv_elf_gas.o... ...skipped <pbin.v2/libs/context/build/gcc-4.5.3/release/link-static/threading-multi>libboost_context.a for lack of <pbin.v2/libs/context/build/gcc-4.5.3/release/link-static/threading-multi>asm/make_i386_sysv_elf_gas.o... ... common.mkdir bin.v2/libs/locale/build/gcc-4.5.3/release/link-static common.mkdir bin.v2/libs/locale/build/gcc-4.5.3/release/link-static/threading-multi gcc.compile.c++ bin.v2/libs/iostreams/build/gcc-4.5.3/release/link-static/threading-multi/bzip2.o libs\iostreams\src\bzip2.cpp:20:56: fatal error: bzlib.h: No such file or directory compilation terminated. "g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -mthreads -DBOOST_ALL_NO_LIB=1 -DBOOST_IOSTREAMS_USE_DEPRECATED -DNDEBUG -I"." -c -o "bin.v2\libs\iostreams\build\gcc-4.5.3\release\link-static\threading-multi\bzip2.o" "libs\iostreams\src\bzip2.cpp" ...failed gcc.compile.c++ bin.v2/libs/iostreams/build/gcc-4.5.3/release/link-static/threading-multi/bzip2.o... ...skipped <pbin.v2/libs/iostreams/build/gcc-4.5.3/release/link-static/threading-multi>libboost_iostreams.a(clean) for lack of <pbin.v2/libs/iostreams/build/gcc-4.5.3/release/link-static/threading-multi>bzip2.o... ...skipped <pbin.v2/libs/iostreams/build/gcc-4.5.3/release/link-static/threading-multi>libboost_iostreams.a for lack of <pbin.v2/libs/iostreams/build/gcc-4.5.3/release/link-static/threading-multi>bzip2.o... ... ...failed updating 6 targets... ...skipped 14 targets... ...updated 3818 targets...

2 2

bjam compiler error
by Christian Henning 26 Feb '13

26 Feb '13

Hi, I'm getting an compiler error when I try to build gil::io documentation. ...patience... ...patience... ...found 1737 targets... ...updating 5 targets... compile-c-c++ ..\..\..\..\bin.v2\tools\quickbook\src\msvc-10.0\release\link-static\threading-multi\values.obj values.cpp C:\boost\tools\quickbook\src\values.cpp(444) : error C2593: 'operator ==' is ambiguous ..\..\..\..\boost/utility/string_ref.hpp(275): could be 'bool boost::operator ==<char,std::char_traits<char>>(boost::basic_string_ref<charT,traits>,boost::basic_string_ref<charT,traits>)' [found using argument-dependent lookup] with [ charT=char, traits=std::char_traits<char> ] ..\..\..\..\boost/utility/string_ref.hpp(270): or 'bool boost::operator ==<char,std::char_traits<char>>(boost::basic_string_ref<charT,traits>,boost::basic_string_ref<charT,traits>)' [found using argument-dependent lookup] with [ charT=char, traits=std::char_traits<char> ] ..\..\..\..\boost/utility/string_ref.hpp(265): or 'bool boost::operator ==<char,std::char_traits<char>>(boost::basic_string_ref<charT,traits>,boost::basic_string_ref<charT,traits>)' [found using argument-dependent lookup] with [ charT=char, traits=std::char_traits<char> ] while trying to match the argument list '(boost::string_ref, boost::string_ref)' C:\boost\tools\quickbook\src\values.cpp(499) : error C2593: 'operator ==' is ambiguous ..\..\..\..\boost/utility/string_ref.hpp(275): could be 'bool boost::operator ==<char,std::char_traits<char>>(boost::basic_string_ref<charT,traits>,boost::basic_string_ref<charT,traits>)' [found using argument-dependent lookup] with [ charT=char, traits=std::char_traits<char> ] ..\..\..\..\boost/utility/string_ref.hpp(270): or 'bool boost::operator ==<char,std::char_traits<char>>(boost::basic_string_ref<charT,traits>,boost::basic_string_ref<charT,traits>)' [found using argument-dependent lookup] with [ charT=char, traits=std::char_traits<char> ] ..\..\..\..\boost/utility/string_ref.hpp(265): or 'bool boost::operator ==<char,std::char_traits<char>>(boost::basic_string_ref<charT,traits>,boost::basic_string_ref<charT,traits>)' [found using argument-dependent lookup] with [ charT=char, traits=std::char_traits<char> ] while trying to match the argument list '(boost::string_ref, boost::string_ref)' call "C:\program files (x86)\microsoft visual studio 10.0\VC\vcvarsall.bat" x86 >nul cl /Zm800 -nologo @"..\..\..\..\bin.v2\tools\quickbook\src\msvc-10.0\release\link-static\threading-multi\values.obj.rsp" ...failed compile-c-c++ ..\..\..\..\bin.v2\tools\quickbook\src\msvc-10.0\release\link-static\threading-multi\values.obj... ...skipped <p..\..\..\..\bin.v2\tools\quickbook\src\msvc-10.0\release\link-static\threading-multi>quickbook.exe for lack of <p..\..\..\..\bin.v2\tools\quickbook\src\msvc-10.0\release\link-static\threading-multi>values.obj... ...skipped <p..\..\..\..\bin.v2\libs\gil\io\doc\msvc-10.0\debug\threading-multi>io.xml for lack of <p..\..\..\..\bin.v2\tools\quickbook\src\msvc-10.0\release\link-static\threading-multi>quickbook.exe... ...skipped <p..\..\..\..\bin.v2\libs\gil\io\doc\msvc-10.0\debug\threading-multi>io.docbook for lack of <p..\..\..\..\bin.v2\libs\gil\io\doc\msvc-10.0\debug\threading-multi-object(xinclude-scanner)@1505>io.xml... ...skipped <phtml>standalone_HTML.manifest for lack of <p..\..\..\..\bin.v2\libs\gil\io\doc\msvc-10.0\debug\threading-multi>io.docbook... ...failed updating 1 target... ...skipped 4 targets... Regards, Christian

5 5

[type_erasure] Some issues
by Fabio Fracassi 25 Feb '13

25 Feb '13

Hi Steven, I recently gave a presentation about type erasure in general, and your library in particular, at our local C++ UG (see here http://prezi.com/kg6d82f-_yky/type-erasure/ or the examples at https://github.com/CppUGBerlin/Talks/tree/master/2013_02_19_TypeErasure if you are interested). During the preparation I discovered some issues I'd like to ask you about. First I think I discovered a bug either in your lib or in clang(with libc++) when compiling one of the documentation examples in C++11 mode. #include <boost/type_erasure/any.hpp> #include <boost/type_erasure/any_cast.hpp> #include <boost/type_erasure/builtin.hpp> #include <boost/type_erasure/operators.hpp> #include <boost/type_erasure/tuple.hpp> #include <iostream> namespace bte = boost::type_erasure; namespace mpl = boost::mpl; int main() { typedef bte::any< mpl::vector< bte::copy_constructible<>, bte::typeid_<>, bte::addable<>, bte::ostreamable<> > > any_type; any_type x(10); any_type y(7); any_type z(x + y); std::cout << z << std::endl; } Compiling this in C++03 mode is fine, in C++11 mode it fails with this error: In file included from te_multi03.cpp:5: ../../Staging/type_erasure/boost/type_erasure/operators.hpp:187:1: error: no matching function for call to 'call' BOOST_TYPE_ERASURE_BINARY_OPERATOR(addable, +) see [1] below for full error. The next are some things which I didn't get to work, and the documentation is silent on any pitfalls. I tried to implement Sean Parent's example from his Value Semantics talk and failed to write a concept that calls free functions instead of members. Here is what I tried (full code and error at [2] below): template<class OBJ, class T> struct drawable { static void apply(const OBJ& obj, T& os, size_t pos) { draw(obj, os, pos); } }; I get an error like: error call to function 'draw' that is neither visible in the template definition nor found by argument-dependent lookup I worked around this problem by defining a concept map, but that is not realy a good solution. On researching a better solution I saw that you already added the convenience macros BOOST_TYPE_ERASURE_MEMBER and BOOST_TYPE_ERASURE_FREE, but didn't have much luck with them. Is there a compileable example where they are used somewhere? Best regards Fabio **** [1] *************************************************************** [1] full error docu example: In file included from te_multi03.cpp:5: ../../Staging/type_erasure/boost/type_erasure/operators.hpp:187:1: error: no matching function for call to 'call' BOOST_TYPE_ERASURE_BINARY_OPERATOR(addable, +) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ../../Staging/type_erasure/boost/type_erasure/operators.hpp:166:20: note: expanded from macro 'BOOST_TYPE_ERASURE_BINARY_OPERATOR' return ::boost::type_erasure::call(name<T, U, R>(), lhs, rhs); \ ^~~~~~~~~~~~~~~~~~~~~~~~~~~ te_multi03.cpp:25:17: note: in instantiation of member function 'boost::type_erasure::operator+' requested here any_type z(x + y); ^ ../../Staging/type_erasure/boost/type_erasure/call.hpp:323:1: note: candidate template ignored: failed template argument deduction call( ^ ../../Staging/type_erasure/boost/type_erasure/call.hpp:356:1: note: candidate template ignored: substitution failure [with Op = boost::type_erasure::addable<boost::type_erasure::_self, boost::type_erasure::_self, boost::type_erasure::_self>, U = <const boost::type_erasure::any<boost::mpl::vector<boost::type_erasure::copy_constructible<boost::type_erasure::_self>, boost::type_erasure::typeid_<boost::type_erasure::_self>, boost::type_erasure::addable<boost::type_erasure::_self, boost::type_erasure::_self, boost::type_erasure::_self>, boost::type_erasure::ostreamable<std::__1::basic_ostream<char>, boost::type_erasure::_self>, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::type_erasure::_self>, boost::type_erasure::param<boost::mpl::vector<boost::type_erasure::copy_constructible<boost::type_erasure::_self>, boost::type_erasure::typeid_<boost::type_erasure::_self>, boost::type_erasure::addable<boost::type_erasure::_self, boost::type_erasure::_self, boost::type_erasure::_self>, boost::type_erasure::ostreamable<std::__1::basic_ostream<char>, boost::type_erasure::_self>, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, const boost::type_erasure::_self &>>]: no type named 'type' in 'boost::type_erasure::detail::call_result<boost::type_erasure::addable<boost::type_erasure::_self, boost::type_erasure::_self, boost::type_erasure::_self>, void (const boost::type_erasure::any<boost::mpl::vector<boost::type_erasure::copy_constructible<boost::type_erasure::_self>, boost::type_erasure::typeid_<boost::type_erasure::_self>, boost::type_erasure::addable<boost::type_erasure::_self, boost::type_erasure::_self, boost::type_erasure::_self>, boost::type_erasure::ostreamable<std::__1::basic_ostream<char>, boost::type_erasure::_self>, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::type_erasure::_self> &, boost::type_erasure::param<boost::mpl::vector<boost::type_erasure::copy_constructible<boost::type_erasure::_self>, boost::type_erasure::typeid_<boost::type_erasure::_self>, boost::type_erasure::addable<boost::type_erasure::_self, boost::type_erasure::_self, boost::type_erasure::_self>, boost::type_erasure::ostreamable<std::__1::basic_ostream<char>, boost::type_erasure::_self>, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, const boost::type_erasure::_self &> &), void>' call( ^ 1 error generated. **** [2] *************************************************************** [2] Code and error for Value semantic example: #include <boost/type_erasure/any.hpp> #include <boost/type_erasure/concept_interface.hpp> #include <boost/type_erasure/rebind_any.hpp> #include <boost/type_erasure/free.hpp> #include <vector> namespace bte = boost::type_erasure; namespace mpl = boost::mpl; //-------------------------------------------------------------------------------------------------- template<class OBJ, class T> struct drawable { static void apply(const OBJ& obj, T& os, size_t pos) { draw(obj, os, pos); } }; namespace boost { namespace type_erasure { template<class OBJ, class T, class Base> struct concept_interface< ::drawable<OBJ, T>, Base, OBJ> : Base { void draw(typename rebind_any<Base, T&>::type os, size_t pos) const { call(::drawable<OBJ, T>(), *this, os, pos); } }; } } using object_t = bte::any< mpl::vector< bte::copy_constructible<>, drawable<bte::_self, std::ostream> >>; //-------------------------------------------------------------------------------------------------- void draw(const int& value, std::ostream& out, size_t position) { out << std::string(position, ' ') << "int = " << value << std::endl; } void draw(const std::string& value, std::ostream& out, size_t position) { out << std::string(position, ' ') << "string = " << value << std::endl; } struct my_class_t {}; void draw(const my_class_t&, std::ostream& out, size_t position) { out << std::string(position, ' ') << "my_class_t" << std::endl; } //-------------------------------------------------------------------------------------------------- using document_t = std::vector<object_t>; // or std::vector<copy_on_write<object_t>>; void draw(const document_t& x, std::ostream& out, size_t position) { out << std::string(position, ' ') << "<document>" << std::endl; for (auto& e : x) { e.draw(out, position + 2); } out << std::string(position, ' ') << "</document>" << std::endl; } //-------------------------------------------------------------------------------------------------- using history_t = std::vector<document_t>; void commit(history_t& x) { assert(x.size()); x.push_back(x.back()); } void undo(history_t& x) { assert(x.size()); x.pop_back(); } document_t& current(history_t& x) { assert(x.size()); return x.back(); } //-------------------------------------------------------------------------------------------------- int main () { history_t h(1); current(h).emplace_back(0); current(h).emplace_back(std::string("Hello!")); draw(current(h), std::cout, 0); std::cout << "--------------------------" << std::endl; commit(h); current(h).emplace_back(current(h)); current(h).emplace_back(my_class_t()); draw(current(h), std::cout, 0); std::cout << "--------------------------" << std::endl; undo(h); draw(current(h), std::cout, 0); } **** Error: ************************************************************ te_sp_copy.cpp:14:59: error: call to function 'draw' that is neither visible in the template definition nor found by argument-dependent lookup static void apply(const OBJ& obj, T& os, size_t pos) { draw(obj, os, pos); } ^ ../../Staging/type_erasure/boost/type_erasure/detail/instantiate.hpp:91:28: note: in instantiation of member function 'drawable<int, std::__1::basic_ostream<char> >::apply' requested here BOOST_PP_REPEAT(N, BOOST_TYPE_ERASURE_INSTANTIATE_IMPL, concept_sequence) ^ /usr/local/include/boost/preprocessor/repetition/repeat.hpp:38:60: note: expanded from macro 'BOOST_PP_REPEAT_1' # define BOOST_PP_REPEAT_1(c, m, d) BOOST_PP_REPEAT_1_I(c, m, d) ^ /usr/local/include/boost/preprocessor/repetition/repeat.hpp:43:63: note: expanded from macro 'BOOST_PP_REPEAT_1_I' # define BOOST_PP_REPEAT_1_I(c, m, d) BOOST_PP_REPEAT_1_ ## c(m, d) ^ /usr/local/include/boost/preprocessor/repetition/repeat.hpp:54:62: note: expanded from macro 'BOOST_PP_REPEAT_1_3' # define BOOST_PP_REPEAT_1_3(m, d) BOOST_PP_REPEAT_1_2(m, d) m(2, 2, d) ^ ../../Staging/type_erasure/boost/type_erasure/detail/instantiate.hpp:70:47: note: expanded from macro 'BOOST_TYPE_ERASURE_INSTANTIATE_IMPL' (void)&::boost::mpl::at_c<data, n>::type::apply; ^ ../../Staging/type_erasure/boost/type_erasure/any.hpp:182:13: note: in instantiation of function template specialization 'boost::type_erasure::detail::instantiate_concept3::apply<boost::mpl::vector<boost::type_erasure::copy_constructible<boost::type_erasure::_self>, drawable<boost::type_erasure::_self, std::__1::basic_ostream<char> >, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::mpl::map1<boost::mpl::pair<boost::type_erasure::_self, int> > >' requested here BOOST_TYPE_ERASURE_INSTANTIATE1(Concept, T, U), ^ ../../Staging/type_erasure/boost/type_erasure/detail/instantiate.hpp:51:14: note: expanded from macro 'BOOST_TYPE_ERASURE_INSTANTIATE1' >::type::apply( \ ^ /usr/bin/../lib/c++/v1/memory:1681:31: note: in instantiation of function template specialization 'boost::type_erasure::any<boost::mpl::vector<boost::type_erasure::copy_constructible<boost::type_erasure::_self>, drawable<boost::type_erasure::_self, std::__1::basic_ostream<char> >, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::type_erasure::_self>::any<int>' requested here ::new((void*)__p) _Up(_VSTD::forward<_Args>(__args)...); ^ /usr/bin/../lib/c++/v1/memory:1608:18: note: in instantiation of function template specialization 'std::__1::allocator<boost::type_erasure::any<boost::mpl::vector<boost::type_erasure::copy_constructible<boost::type_erasure::_self>, drawable<boost::type_erasure::_self, std::__1::basic_ostream<char> >, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::type_erasure::_self> >::construct<boost::type_erasure::any<boost::mpl::vector<boost::type_erasure::copy_constructible<boost::type_erasure::_self>, drawable<boost::type_erasure::_self, std::__1::basic_ostream<char> >, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::type_erasure::_self>, int>' requested here {__a.construct(__p, _VSTD::forward<_Args>(__args)...);} ^ /usr/bin/../lib/c++/v1/memory:1492:14: note: in instantiation of function template specialization 'std::__1::allocator_traits<std::__1::allocator<boost::type_erasure::any<boost::mpl::vector<boost::type_erasure::copy_constructible<boost::type_erasure::_self>, drawable<boost::type_erasure::_self, std::__1::basic_ostream<char> >, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::type_erasure::_self> > >::__construct<boost::type_erasure::any<boost::mpl::vector<boost::type_erasure::copy_constructible<boost::type_erasure::_self>, drawable<boost::type_erasure::_self, std::__1::basic_ostream<char> >, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::type_erasure::_self>, int>' requested here {__construct(__has_construct<allocator_type, pointer, _Args...>(), ^ /usr/bin/../lib/c++/v1/vector:1519:25: note: in instantiation of function template specialization 'std::__1::allocator_traits<std::__1::allocator<boost::type_erasure::any<boost::mpl::vector<boost::type_erasure::copy_constructible<boost::type_erasure::_self>, drawable<boost::type_erasure::_self, std::__1::basic_ostream<char> >, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::type_erasure::_self> > >::construct<boost::type_erasure::any<boost::mpl::vector<boost::type_erasure::copy_constructible<boost::type_erasure::_self>, drawable<boost::type_erasure::_self, std::__1::basic_ostream<char> >, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::type_erasure::_self>, int>' requested here __alloc_traits::construct(this->__alloc(), ^ te_sp_copy.cpp:71:15: note: in instantiation of function template specialization 'std::__1::vector<boost::type_erasure::any<boost::mpl::vector<boost::type_erasure::copy_constructible<boost::type_erasure::_self>, drawable<boost::type_erasure::_self, std::__1::basic_ostream<char> >, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::type_erasure::_self>, std::__1::allocator<boost::type_erasure::any<boost::mpl::vector<boost::type_erasure::copy_constructible<boost::type_erasure::_self>, drawable<boost::type_erasure::_self, std::__1::basic_ostream<char> >, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::type_erasure::_self> > >::emplace_back<int>' requested here current(h).emplace_back(0); ^ te_sp_copy.cpp:33:6: note: 'draw' should be declared prior to the call site void draw(const int& value, std::ostream& out, size_t position) { ^ te_sp_copy.cpp:14:59: error: call to function 'draw' that is neither visible in the template definition nor found by argument-dependent lookup static void apply(const OBJ& obj, T& os, size_t pos) { draw(obj, os, pos); } ^ ../../Staging/type_erasure/boost/type_erasure/detail/instantiate.hpp:91:28: note: in instantiation of member function 'drawable<std::__1::basic_string<char>, std::__1::basic_ostream<char> >::apply' requested here BOOST_PP_REPEAT(N, BOOST_TYPE_ERASURE_INSTANTIATE_IMPL, concept_sequence) ^ /usr/local/include/boost/preprocessor/repetition/repeat.hpp:38:60: note: expanded from macro 'BOOST_PP_REPEAT_1' # define BOOST_PP_REPEAT_1(c, m, d) BOOST_PP_REPEAT_1_I(c, m, d) ^ /usr/local/include/boost/preprocessor/repetition/repeat.hpp:43:63: note: expanded from macro 'BOOST_PP_REPEAT_1_I' # define BOOST_PP_REPEAT_1_I(c, m, d) BOOST_PP_REPEAT_1_ ## c(m, d) ^ /usr/local/include/boost/preprocessor/repetition/repeat.hpp:54:62: note: expanded from macro 'BOOST_PP_REPEAT_1_3' # define BOOST_PP_REPEAT_1_3(m, d) BOOST_PP_REPEAT_1_2(m, d) m(2, 2, d) ^ ../../Staging/type_erasure/boost/type_erasure/detail/instantiate.hpp:70:47: note: expanded from macro 'BOOST_TYPE_ERASURE_INSTANTIATE_IMPL' (void)&::boost::mpl::at_c<data, n>::type::apply; ^ ../../Staging/type_erasure/boost/type_erasure/any.hpp:182:13: note: in instantiation of function template specialization 'boost::type_erasure::detail::instantiate_concept3::apply<boost::mpl::vector<boost::type_erasure::copy_constructible<boost::type_erasure::_self>, drawable<boost::type_erasure::_self, std::__1::basic_ostream<char> >, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::mpl::map1<boost::mpl::pair<boost::type_erasure::_self, std::__1::basic_string<char> > > >' requested here BOOST_TYPE_ERASURE_INSTANTIATE1(Concept, T, U), ^ ../../Staging/type_erasure/boost/type_erasure/detail/instantiate.hpp:51:14: note: expanded from macro 'BOOST_TYPE_ERASURE_INSTANTIATE1' >::type::apply( \ ^ /usr/bin/../lib/c++/v1/memory:1681:31: note: in instantiation of function template specialization 'boost::type_erasure::any<boost::mpl::vector<boost::type_erasure::copy_constructible<boost::type_erasure::_self>, drawable<boost::type_erasure::_self, std::__1::basic_ostream<char> >, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::type_erasure::_self>::any<std::__1::basic_string<char> >' requested here ::new((void*)__p) _Up(_VSTD::forward<_Args>(__args)...); ^ /usr/bin/../lib/c++/v1/memory:1608:18: note: in instantiation of function template specialization 'std::__1::allocator<boost::type_erasure::any<boost::mpl::vector<boost::type_erasure::copy_constructible<boost::type_erasure::_self>, drawable<boost::type_erasure::_self, std::__1::basic_ostream<char> >, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::type_erasure::_self> >::construct<boost::type_erasure::any<boost::mpl::vector<boost::type_erasure::copy_constructible<boost::type_erasure::_self>, drawable<boost::type_erasure::_self, std::__1::basic_ostream<char> >, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::type_erasure::_self>, std::__1::basic_string<char> >' requested here {__a.construct(__p, _VSTD::forward<_Args>(__args)...);} ^ /usr/bin/../lib/c++/v1/memory:1492:14: note: in instantiation of function template specialization 'std::__1::allocator_traits<std::__1::allocator<boost::type_erasure::any<boost::mpl::vector<boost::type_erasure::copy_constructible<boost::type_erasure::_self>, drawable<boost::type_erasure::_self, std::__1::basic_ostream<char> >, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::type_erasure::_self> > >::__construct<boost::type_erasure::any<boost::mpl::vector<boost::type_erasure::copy_constructible<boost::type_erasure::_self>, drawable<boost::type_erasure::_self, std::__1::basic_ostream<char> >, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::type_erasure::_self>, std::__1::basic_string<char> >' requested here {__construct(__has_construct<allocator_type, pointer, _Args...>(), ^ /usr/bin/../lib/c++/v1/vector:1519:25: note: in instantiation of function template specialization 'std::__1::allocator_traits<std::__1::allocator<boost::type_erasure::any<boost::mpl::vector<boost::type_erasure::copy_constructible<boost::type_erasure::_self>, drawable<boost::type_erasure::_self, std::__1::basic_ostream<char> >, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::type_erasure::_self> > >::construct<boost::type_erasure::any<boost::mpl::vector<boost::type_erasure::copy_constructible<boost::type_erasure::_self>, drawable<boost::type_erasure::_self, std::__1::basic_ostream<char> >, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::type_erasure::_self>, std::__1::basic_string<char> >' requested here __alloc_traits::construct(this->__alloc(), ^ te_sp_copy.cpp:72:15: note: in instantiation of function template specialization 'std::__1::vector<boost::type_erasure::any<boost::mpl::vector<boost::type_erasure::copy_constructible<boost::type_erasure::_self>, drawable<boost::type_erasure::_self, std::__1::basic_ostream<char> >, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::type_erasure::_self>, std::__1::allocator<boost::type_erasure::any<boost::mpl::vector<boost::type_erasure::copy_constructible<boost::type_erasure::_self>, drawable<boost::type_erasure::_self, std::__1::basic_ostream<char> >, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::type_erasure::_self> > >::emplace_back<std::__1::basic_string<char> >' requested here current(h).emplace_back(std::string("Hello!")); ^ te_sp_copy.cpp:37:6: note: 'draw' should be declared prior to the call site void draw(const std::string& value, std::ostream& out, size_t position) { ^ 2 errors generated.

2 3

[gil::io] Feedback for scanline_read_iterator
by Christian Henning 25 Feb '13

25 Feb '13

Hi all, I'm getting close to finally commit the new io extension for boost::gil. As it was required from the boost review I have implemented a basic image_read_iterator to read large images. I would like to get some feedback on my interface and maybe on the actual implementation, as well. I must admit this is my first iterator that I have designed and implemented from scratch with some help by other people. The latest io code can be found here via svn: http://code.google.com/p/gil-contributions/source/browse/#svn%2Ftrunk%2Fgil… A basic usage of the code is here: http://pastebin.com/3E7KpfwE Thanks! Christian

7 51

[utility]proposal for a small utility of namespace
by law chrono 25 Feb '13

25 Feb '13

I like c++ and boost，but write namespace is a boring work for brace-matching. So I write a small util with boost.preprocessor, like below: #ifndef BOOST_NAMESPACE_UTILITY_HPP_ #define BOOST_NAMESPACE_UTILITY_HPP_ #include <boost/preprocessor/seq/for_each.hpp> #define _PP_NS_BEGIN_FUNC(r,data,elem) namespace elem { #define _PP_NS_END_FUNC(r,data,elem) } #define BOOST_BEGIN_NAMESPACE(SEQ) \ BOOST_PP_SEQ_FOR_EACH(_PP_NS_BEGIN_FUNC, ~, SEQ) #define BOOST_ END_ NAMESPACE (SEQ) \ BOOST_PP_SEQ_FOR_EACH(_PP_NS_END_FUNC, ~, SEQ) #endif //BOOST_NAMESPACE_UTILITY_HPP_ Then the code can be more clear and easy-reading: BOOST_BEGIN_NAMESPACE((boost)(asio)(ip)) //namespace boost{namespace asio{namespace ip{ ... //to something BOOST_END_NAMESPACE((boost)(asio)(ip)) //}}} c++11 inline namespace also can work: inline BOOST_BEGIN_NAMESPACE((detail)) ... //to something BOOST_END_NAMESPACE((detail)) I wander to know whether this util could be a part of boost. Thanks a lot.

3 2

[thread|shared_ptr|atomic] segmentation fault in exception_ptr assignment
by Oliver Kowalke 24 Feb '13

24 Feb '13

I've replaced shared_ptr<> by intrusive_ptr<> + atomic< std::size_t > in boost.thread's future implementation. atomic< std::size_t > use_count; // initialized with '0' in ctor friend inline void intrusive_ptr_add_ref( future_continuation_base * p) BOOST_NOEXCEPT { ++p->use_count; // should be seq_cst } friend inline void intrusive_ptr_release( future_continuation_base * p) { if ( 0 == --p->use_count) // should be seq_cst delete p; } I get an error if I compile the code with gcc-4.7.2 on x86_64: segmentation fault backtrace: 0x0000000000426a96 in boost::detail::atomic_exchange_and_add (pw=0x436a40, dv=-1) at ../../../boost/smart_ptr/detail/sp_counted_base_gcc_x86.hpp:50 50 ); (gdb) bt #0 0x0000000000426a96 in boost::detail::atomic_exchange_and_add (pw=0x436a40, dv=-1) at ../../../boost/smart_ptr/detail/sp_counted_base_gcc_x86.hpp:50 #1 0x0000000000426ba7 in boost::detail::sp_counted_base::release (this=0x436a38) at ../../../boost/smart_ptr/detail/sp_counted_base_gcc_x86.hpp:143 #2 0x0000000000426c57 in boost::detail::shared_count::~shared_count (this=0x7fffffffc868, __in_chrg=<optimized out>) at ../../../boost/smart_ptr/detail/shared_count.hpp:368 #3 0x0000000000427c3e in boost::shared_ptr<boost::exception_detail::clone_base const>::~shared_ptr (this=0x7fffffffc860, __in_chrg=<optimized out>) at ../../../boost/smart_ptr/shared_ptr.hpp:316 #4 0x000000000042b2cd in boost::shared_ptr<boost::exception_detail::clone_base const>::operator= (this=0x75df00, r=...) at ../../../boost/smart_ptr/shared_ptr.hpp:485 #5 0x0000000000427d6f in boost::exception_ptr::operator= (this=0x75df00, other=...) at ../../../boost/exception/detail/exception_ptr.hpp:73 #6 0x0000000000429a2f in boost::fibers::detail::future_object_base::mark_exceptional_finish_internal (this=0x75def0, e=..., lock=...) at ../../../boost/fiber/future.hpp:278 #7 0x000000000043749a in boost::fibers::detail::task_base<int>::owner_destroyed (this=0x75def0) at ../../../boost/fiber/future.hpp:1241 #8 0x000000000042e768 in boost::fibers::packaged_task<int>::~packaged_task (this=0x7fffffffc9b0, __in_chrg=<optimized out>) at ../../../boost/fiber/future.hpp:1341 called funtions: ~packaged_task() -> task_base::owner_destroyed() -> future_object_base::mark_exceptional_finish_internal() -> exception_ptr::operator=(excepton_ptr const&) -> shared_ptr -> shared_count -> sp_counted_base_gcc_x86 -> boost::detail::atomic_exchange_and_add() I'm wondering why a simple assignement of excpetion_ptr causes a segmentation fault if future's implementation uses intrusive_ptr + atomic + sequential - consistent ops instead of shared_ptr. Does someone have an explanation?

2 1

[thread] ~condition_variable_any verifications
by Tim Blechmann 24 Feb '13

24 Feb '13

hi, one of my project uses exit() to terminate the program. this is sometimes called while some threads are waiting on a global condition_variable_any. when calling exit(), this global variable is destroyed while other threads are still waiting on it, which causes BOOST_VERIFY to fire an assertion failure !pthread_cond_destroy(&cond). this scares the hell out of my users. i know that these verifications can be really useful in many case, but in my use case, it makes exit() rather unusable, and i'd have to redesign some of the internal logic to avoid this assertion failure. thoughts? thnx, tim

4 5