January 2013 - Boost-users - lists.preview.boost.org

[Container] --begin() on empty deque crashes
by TONGARI 20 Jan '13

20 Jan '13

Hi there, The code below would simply crash on g++ 4.7.1/MinGW with default optimization level, it doesn't shown with -O/1/2/3 ---------------------------------------- boost::container::deque<int> d; --d.begin(); ---------------------------------------- I took a look into the impl, seems that it dereferences from (this->m_node - 1) which is invalid at the time. I guess it's the problem. Thoughts?

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[asio] How do you fake the time for boost timers?
by Josh Quigley 20 Jan '13

20 Jan '13

(For those interested this question is also at http://stackoverflow.com/questions/14191855/how-do-you-fake-the-time-for-bo… ) Hi all, If possible, how do you fake the time for the purpose of triggering boost timers in a unit test? For example, is it possible to achieve something like the following: #include <iostream>#include <boost/asio.hpp>#include <boost/date_time/posix_time/posix_time.hpp> void print(const boost::system::error_code& /*e*/){ std::cout << "… [View More]

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[MultiIndex] more on key extractor issues
by John M. Dlugosz 19 Jan '13

19 Jan '13

I think my problem stems from the use of 'const' in the underlying element with pointer traversal. Consider: typedef multi_index_container< shared_ptr< const ItemBase >, indexed_by< ordered_non_unique< member< const ItemBase, // <<--- here const unsigned long, // <<--- here &ItemBase::some_member > >, // ordered_non_unique ordered_unique< … [View More] tag<S2>, member< ItemBase, const S2, &ItemBase::another_member > > // ordered_unique > // indexed_by > ItemList_type_base; I added the two 'const' occurrences on the lines marked with "here", and it behaved better. I think it worked with the second index originally because one of those const's was originally there. The member in question was originally const, so I had included const as part of the type there. Basically, what is happening on Windows VS10 is: template<class Class,typename Type,Type Class::*PtrToMember> struct non_const_member_base { typedef Type result_type; template<typename ChainedPtr> #if !defined(BOOST_NO_SFINAE) typename disable_if< is_convertible<const ChainedPtr&,const Class&>,Type&>::type #else Type& #endif operator()(const ChainedPtr& x)const { return operator()(*x); // <<-- HERE } const Type& operator()(const Class& x,int=0)const { return x.*PtrToMember; } Type& operator()(Class& x)const { return x.*PtrToMember; } }; The ChainedPointer form unpeels a const-qualified type with (*x), and that matches the middle form, not the third. But the signature on the first form is looking for Type, which is exactly what I put in the member<...> index directive. So, I suggest that a quick note concerning constant types inside chained pointer following could be added to the tutorial section. Meanwhile, a stranger problem occured on the Mac, using the Clang compiler. I got an error saying that none of the operator() candidates were viable for overloading, with the error indicating that the type of thing being passed in was the shared_ptr<const ItemBase>. It said the first form was ignored because of instantiation failure, but that is exactly contrary to the disable_if. I'm suspecting that the is_convertable itself somehow choked rather than producing false_type...? Naturally none of the other overloads matched, as a shared_ptr<T> cannot be passed where a T is expected, and that's exactly when the first form would be switched in! —John [View Less]

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[MultiIndex] is ordered_non_unique stable?
by John M. Dlugosz 19 Jan '13

19 Jan '13

Will equivalent elements in a ordered_non_unique index be "stable" and maintain their relative ordering based on the order in which they were inserted? Or do I need to use a complex key, adding my own sequence number, to ensure the desired ordering? —John

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Re: [Boost-users] [serialization] Serializing derived
by Brown, Matt 18 Jan '13

18 Jan '13

Hi Daniel, You may have already considered this option, but what if you were to require a template argument for which the user could pass a serialization behavior class ... much like an allocator for STL containers. I.E. YOUR CODE: template <typename T, typename serialize_T> struct container { void serialize(unsigned version) {serialize_T::do(data, version);} virtual ~container() = default; T data; }; USER'S CODE: struct my_serialize { static void do(SOME_TYPE data, unsigned … [View More]

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[Phoenix][Range] What's wrong here...
by Robert Jones 18 Jan '13

18 Jan '13

Hi All Can anyone tell me what's wrong with this? The error message is so huge I'm a bit overwhelmed! I suspect type deduction is failing, but none of my efforts to correct it have worked. Thx, Rob. #include <boost/phoenix/bind.hpp> #include <boost/phoenix/bind/bind_function_object.hpp> #include <boost/phoenix/core.hpp> #include <boost/phoenix/operator.hpp> #include <boost/range/adaptor/adjacent_filtered.hpp> #include <boost/range/algorithm/for_each.hpp> … [View More]

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[serialization] Serializing derived template class via base pointer
by Daniel Mitchell 18 Jan '13

18 Jan '13

Hi everyone, has any progress has been made on a general solution for this problem? Given classes like these, struct base { template<typename Archive> void serialize(Archive& ar, unsigned version) { } virtual ~base() = default; }; template<typename T> struct derived : base { template<typename Archive> void serialize(Archive& ar, unsigned version) { ar & data; } T data; }; is it possible to serialize the derived type (with T unknown) via a base … [View More]

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[MultiIndex] strange problem with simple use of member key extractor
by John M. Dlugosz 18 Jan '13

18 Jan '13

namespace bmi = boost::multi_index; .... bmi::ordered_non_unique< bmi::member< ItemBase, unsigned, &ItemBase::my_member > >, // ordered_non_unique .... I'm getting a compiler error on VS10 from template<class Class,typename Type,Type Class::*PtrToMember> struct non_const_member_base { .... Type& operator()(const ChainedPtr& x)const { return operator()(*x); } … [View More]

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[BGL] Limited depth search without O(number_of_verices) complexity?
by Ilja Honkonen 18 Jan '13

18 Jan '13

Hello Is it possible to do a limited depth depth first search without using O(N) additional memory? The following code seems to visit only a part of the graph but it still requires O(N) memory for the external color map. Could that be avoided with an internal color map? I didn't manage to get depth_first_visit(...) to use an internal color map. Would the solution work also with other graph types besides <vecS, vecS, ...>? #include <iostream> #include <boost/graph/… [View More]

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[MultiIndex] stable? Please help
by John M. Dlugosz 17 Jan '13

17 Jan '13

earlier I posted a question as to whether a non-unique index in MultiIndex is "stable" with regards to insertion order. Can anyone speak to this?

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boost::range RangeConcept problem.
by Hurcan Solter 17 Jan '13

17 Jan '13

The following snippet is the mock-up of the problem I am having in order to be able to reproduce. -------------------------------------------------------------------------------- #include <iostream> #include <boost/range.hpp> #include <boost/range/adaptors.hpp> #include <boost/range/algorithm.hpp> #include <boost/bind.hpp> #include <boost/assign.hpp> using namespace boost::assign; struct wxSize { wxSize(int height=0,int width=0):m_height(height),… [View More]

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[thread][move] compiling move(thread) with Android NDK GCC4.7
by Igor R 17 Jan '13

17 Jan '13

Hello, I'm building my project with Android NDK toolchain (Boost1.51, GCC4.6 or GCC4.7), and I get the following error when trying to move thread. Is there any workaround for this issue? //... vector_.push_back(boost::move(thread(&func, arg))); //... try.cpp:86:62: error: no matching function for call to 'move(boost::thread)' try.cpp:86:62: note: candidates are: In file included from boost/thread/detail/move.hpp:20:0, from boost/thread/locks.hpp:11, from … [View More]boost/thread/pthread/mutex.hpp:12, from boost/thread/mutex.hpp:16, from boost/thread/pthread/thread_data.hpp:13, from boost/thread/thread.hpp:17, from boost/thread.hpp:13, from try.h:3, from try.cpp:6: boost/move/move.hpp:324:97: note: template<class T> typename boost::move_detail::disable_if<boost::has_move_emulation_enabled_aux<T>, T&>::type boost::move(T&) boost/move/move.hpp:324:97: note: template argument deduction/substitution failed: boost/move/move.hpp: In substitution of 'template<class T> typename boost::move_detail::disable_if<boost::has_move_emulation_enabled_aux<T>, T&>::type boost::move(T&) [with T = boost::thread]': try.cpp:86:62: required from here boost/move/move.hpp:324:97: error: no type named 'type' in 'struct boost::move_detail::disable_if<boost::has_move_emulation_enabled_aux<boost::thread>, boost::thread&>' boost/move/move.hpp:330:96: note: template<class T> typename boost::move_detail::enable_if<boost::has_move_emulation_enabled<T>, boost::rv<T>&>::type boost::move(T&) boost/move/move.hpp:330:96: note: template argument deduction/substitution failed: boost/move/move.hpp: In substitution of 'template<class T> typename boost::move_detail::enable_if<boost::has_move_emulation_enabled<T>, boost::rv<T>&>::type boost::move(T&) [with T = boost::thread]': try.cpp:86:62: required from here boost/move/move.hpp:330:96: error: no type named 'type' in 'struct boost::move_detail::enable_if<boost::has_move_emulation_enabled<boost::thread>, boost::rv<boost::thread>&>' boost/move/move.hpp:336:96: note: template<class T> typename boost::move_detail::enable_if<boost::has_move_emulation_enabled<T>, boost::rv<T>&>::type boost::move(boost::rv<T>&) boost/move/move.hpp:336:96: note: template argument deduction/substitution failed: try.cpp:86:62: note: 'boost::thread' is not derived from 'boost::rv<T>' In file included from boost/thread/detail/move.hpp:20:0, from boost/thread/locks.hpp:11, from boost/thread/pthread/mutex.hpp:12, from boost/thread/mutex.hpp:16, from boost/thread/pthread/thread_data.hpp:13, from boost/thread/thread.hpp:17, from boost/thread.hpp:13, from try.h:3, from try.cpp:6: boost/move/move.hpp:943:6: note: template<class I, class O> O boost::move(I, I, O) boost/move/move.hpp:943:6: note: template argument deduction/substitution failed: try.cpp:86:62: note: candidate expects 3 arguments, 1 provided In file included from boost/thread/locks.hpp:11:0, from boost/thread/pthread/mutex.hpp:12, from boost/thread/mutex.hpp:16, from boost/thread/pthread/thread_data.hpp:13, from boost/thread/thread.hpp:17, from boost/thread.hpp:13, from try.h:3, from try.cpp:6: boost/thread/detail/move.hpp:55:124: note: typename boost::enable_if<boost::is_convertible<T&, boost::detail::thread_move_t<T> >, boost::detail::thread_move_t<T> >::type boost::move(T&) [with T = boost::thread; typename boost::enable_if<boost::is_convertible<T&, boost::detail::thread_move_t<T> >, boost::detail::thread_move_t<T> >::type = boost::detail::thread_move_t<boost::thread>] boost/thread/detail/move.hpp:55:124: note: no known conversion for argument 1 from 'boost::thread' to 'boost::thread&' In file included from boost/thread/locks.hpp:11:0, from boost/thread/pthread/mutex.hpp:12, from boost/thread/mutex.hpp:16, from boost/thread/pthread/thread_data.hpp:13, from boost/thread/thread.hpp:17, from boost/thread.hpp:13, from try.h:3, from try.cpp:6: boost/thread/detail/move.hpp:62:37: note: template<class T> boost::detail::thread_move_t<T> boost::move(boost::detail::thread_move_t<T>) boost/thread/detail/move.hpp:62:37: note: template argument deduction/substitution failed: try.cpp:86:62: note: 'boost::thread' is not derived from 'boost::detail::thread_move_t<T>' [View Less]

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FW: ASIO io_service performance under single or multiple io_services questions
by Bryan Fok 17 Jan '13

17 Jan '13

To asio users, I am confused by the results from my experiments with asio recently. Firstly, am I correct that, when OS I/O buffer is ready to be read, io_service will only pick an available thread from its thread pool to notify the socket's complete handler? For example, if I have a single io_service with 1 thread, and 100 udp sockets executed async_read_from. Hypothetically, if they all simultaneously ready to read from OS kernel buffer, would the io_service notify each socket's … [View More]

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[asio][chrono] using steady_timer portably
by Igor R 17 Jan '13

17 Jan '13

Hello, There's some use of asio::steady_timer in my code (1.51): asio::steady_timer timer_; //....... timer_.expires_from_now(boost::chrono::milliseconds(100)); //...... However, the above appears to be non-portable, as under c++11 steady_timer uses std::chrono, while boost::chrono doesn't seem to "forward" its types to std::chrono. I know I can use asio::basic_waitable_timer<boost::chrono::steady_clock> explicitly, but maybe there's some more straightforward solution (eg. boost::chrono configuration)? Thanks.

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Why is boost::format::operator% not declared const?
by Chris Stankevitz 17 Jan '13

17 Jan '13

Hello, I use boost::format to convert a float to a string: void CalledThousandsOfTimesPerSecond(float f) { GetStream() << boost::format("%0.3f") % f << GetSomeOtherContent(); } I normally would deal with something like this by adding a static const variable: void CalledThousandsOfTimesPerSecondFromManyThreads(float f) { static const boost::format Formatter("%0.3f"); GetStream() << Formatter % f << GetSomeOtherContent(); } But this does not work. boost::… [View More]

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Re: [Boost-users] shared memory between 32b and 64b
by Dave Dyer 17 Jan '13

17 Jan '13

Thanks, this pair of definitions gets off the ground. typedef offset_ptr< void , boost::int32_t , boost::uint64_t > my_offset_ptr; typedef basic_managed_shared_memory <char ,rbtree_best_fit<mutex_family, my_offset_ptr> ,iset_index> compat32_shared_memory;

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shared memory between 32b and 64b
by Dave Dyer 16 Jan '13

16 Jan '13

Looked promising, but not quite good enough. I dedined: typedef offset_ptr<class T, std::ptrdiff_t, unsigned long long>my_offset_ptr; typedef basic_managed_shared_memory <char ,rbtree_best_fit<mutex_family, my_offset_ptr> ,iset_index> compat32_shared_memory; in the win64 process I do compat32_shared_memory segment(create_only, SEGMENT_NAME, SEGMENT_SIZE); comm *command = segment.construct<comm>("CommandBlock")(); in the win32 … [View More]

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statechart] [gcc-4.7.2] a template state inherited from statechart::state results in compiler error
by Nikiforov Anatoly 15 Jan '13

15 Jan '13

Hi, I'm using Boost.Statechart and have come across a strange gcc-4.7.2 behavior on the attached sample code. The error is: cpp-lab/boost/statechart/main.cpp:89:23: error: expected ')' before 'ctx' If outermost_context() isn't used in Inner3() constructor and statechart::simple_state is used instead of statechart::state everything is OK. If Inner3 is not a template then everything is OK The problem occurs only if a state template class is inherited from statechart::state. Is there any … [View More]

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[Property Tree] Debugger visualizer for property tree
by Elizabeta 15 Jan '13

15 Jan '13

Hi I need debugger visualizer for property tree. Can't find it here https://svn.boost.org/svn/boost/sandbox/boost_docs/subprojects/DebuggerVisu…, I guess it doesn't exist. Any plans for making it in near future ?

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64 bits migration problems
by simone pilozzi 15 Jan '13

15 Jan '13

Dear Users, I am experiencing a lot of issues in compiling my VC 2010 projects with a 64 bits machin (while they work happily witha 32 bits). I downloaded the 1_51 version of boost for 64bits and I obtained the following error with the serialization library: Error 495 error LNK1104: cannot open file 'libboost_serialization-vc100-mt-gd-1_51.lib Then I tried some older version ( 1_47, i ) but I received this series of compiling errors related again to the xml archive. Error 493 error LNK2019: … [View More]

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Runtime Library Error in C++ called boost.python and custom module
by simon zhang 12 Jan '13

12 Jan '13

I have called some python in C++,then python will called a custom module that was writed by c++. This problem occured when I track, python call custom module. Error: Microsoft Visual C++ Runtime Library Runtime Error!Program:xxxxx.exe R6034An application has made an attempt to load the C runtime library incorrectly.Please contact the application's support team for more information. Detailed descriptions： Environment：　　　winxp,Mingw4.7+MSYS,Library：　　　wxwidgets2.8 static compile (called … [View More]

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[thread] Can Boost.Thread use Boost.Atomic without falling on a compatibility issue?
by Vicente J. Botet Escriba 12 Jan '13

12 Jan '13

Hi, in order to fix this issue, https://svn.boost.org/trac/boost/ticket/5752 : "boost::call_once() is unreliable on some platforms", I would like to use Boost.Atomic as suggested on the ticket. As Boost.Atomic is not a header-only library the user would need to link with boost_atomic. Is this an acceptable change? I'm requesting this as recently there were some people reactive to some changes in Boost.Thread. Would this be considered an compatibility issue? If yes should the fix for the … [View More]

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Newbie Question
by Walker.Kyle 12 Jan '13

12 Jan '13

It appears the following code has a warning detected by GCC4.7.2: /boost/include/boost-1_52/boost/property_tree/detail/ptree_utils.hpp: In instantiation of 'std::string boost::property_tree::detail::narrow(const Ch*) [with Ch = wchar_t; std::string = std::basic_string<char, std::char_traits<char>, std::allocator<char> >]': /boost/include/boost-1_52/boost/property_tree/string_path.hpp:64:36: required from here /boost/include/boost-1_52/boost/property_tree/detail/ptree_utils.… [View More]

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Boost and -fvisibility=hidden
by Dániel Varga 11 Jan '13

11 Jan '13

Hi, I would like to add symbol visibility support to my library. Using -fvisibility=hidden option I compared the changed symbols, boost::bad_function_call typeinfo was visible previously but with hidden default visibility it is hidden. It compiles just fine, but according to gcc wiki (http://gcc.gnu.org/wiki/Visibility) exceptions must be visible as runtime error might happen because of missing typeinfo. I found bug report (https://svn.boost.org/trac/boost/ticket/2309) that exception class not … [View More]

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Re: [Boost-users] mixed 32 bit and 54 bit
by Dave Dyer 11 Jan '13

11 Jan '13

> > >You need to define an offset_ptr with 64 bit OffsetType > >typedef offset_ptr<T, std::ptrdiff_t, unsigned long long> my_offset_ptr; > >and instantiate all interprocess managed resources like >(basic_managed_shared_memory) like this: > > >typedef basic_managed_shared_memory > <char > ,rbtree_best_fit<mutex_family, my_offset_ptr> > ,iset_index> >managed_shared_memory; > >Again, this is not supported and it's still … [View More]

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