July 2008 - Boost-users - lists.preview.boost.org

Re: [Boost-users] Boost spirit: overlapping inner struct result
by Kesseli Pascal 31 Jul '08

31 Jul '08

Hi Joel Thanks for your reply. That simple example you stated compiles fine, though. Is it possible that the templates might have ane impact here? "Joel de Guzman" <joel(a)boost-consulting.com> schrieb im Newsbeitrag news:<g6pu9q$r4b$1(a)ger.gmane.org>... > Pascal Kesseli wrote: > > Hi everyone > > > > When trying to compile the serialization library for my Montavista embedded > > computer, I am getting a strange error message concerning boost > > spirit/core/primitives/numerics.hpp stating that struct result in > > sign_parser has already been defined before. > > > > Back then, I couldn't deny that fact, as result is already defined in > > sign_parser's superclass parser, so I renamed the struct in the subclass to > > tresult and the library compiled fine. > > > > Currently, I am asking myself what influence such a change might have on > > the > > running program. I am having unexplainable SIGABRT signals appearing and > > killing my program, thus I suspect my change was not that mere after all. > > > > Is there a better workaround I could use to solve this problem? > > > > Thanks in advance for your replies and best regards > > I don't quite understand what's happening here. It shouldn't be > an error if a base class and a subclass share the same result > struct. Try this short example: > > struct x > { > struct result { typedef int type; }; > }; > > struct y : x > { > struct result { typedef double type; }; > }; > > Regards, > -- > Joel de Guzman > http://www.boostpro.com > http://spirit.sf.net

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is BOOST_STATIC_WARNING part of boost public interface?
by frederic.bron＠alcan.com 31 Jul '08

31 Jul '08

I cannot find any documentation about BOOST_STATIC_WARNING, is it intended to be used by users or only internal to the library? F. Bron Avis : Ce message et toute pièce jointe sont la propriété d'Alcan et sont destinés seulement aux personnes ou à l'entité à qui le message est adressé. Si vous avez reçu ce message par erreur, veuillez le détruire et en aviser l'expéditeur par courriel. Si vous n'êtes pas le destinataire du message, vous n'êtes pas autorisé à utiliser, à copier ou à divulguer le contenu du message ou ses pièces jointes en tout ou en partie. Notice: This message and any attachments are the property of Alcan and are intended solely for the named recipients or entity to whom this message is addressed. If you have received this message in error please inform the sender via e-mail and destroy the message. If you are not the intended recipient you are not allowed to use, copy or disclose the contents or attachments in whole or in part.

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[boost.thread] destruction of condition variables
by Vladimir Pozdyaev 31 Jul '08

31 Jul '08

Hello. Is it feasible to make CVs' destructors thread-safe? Consider the code below. It causes a failed assertion in basic_condition_variable::dispose_entry(...) when cv's destructor kicks in while notify_all() is still cleaning up. The problem is easily resolved by adding another mutex, but it would just look nicer if we could rely on cv's own features for that. Another alternative would be to make wait() return only after notify_xxx() has really finished its job. (Yes, I guess this code is not exactly a Good Practice :) , but it's not exactly logically inconsistent either. Or is it?) [ Boost 1.35.0, MSVC2008, Win32 Debug configuration Actually, it's not easy to make this particular code fail; adding a short sleep() in the beginning of dispose_entry(...) helps. This problem managed to appear quite systematically in a more complex program though. ] ---- Vladimir :::CODE::: #include <boost/thread.hpp> #include <boost/bind.hpp> class C { private: boost::mutex m; boost::condition_variable cv; public: ~C() { boost::mutex::scoped_lock l( m ); cv.wait( l ); } void fn() { boost::this_thread::sleep( boost::posix_time::milliseconds( 500 ) ); cv.notify_all(); } }; int main() { C c; boost::thread t( boost::bind( &C::fn, &c ) ); return 0; }

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Boost with gcc 3.4.3?
by Karthick Gururaj 31 Jul '08

31 Jul '08

Hello, I am porting code which compiles with gcc 3.2.3 and uses boost, to compile for gcc 3.4.3. I get the following compilation errors. Also there are a lot of erros regarding scope, which can be fixed. Can anybody suggest what I should be looking at to resolve this. Regards Karthick /inc/boost/integer_fwd.hpp:70: error: `long_long_type' is not a member of `boost' /inc/boost/integer_fwd.hpp:70: error: `long_long_type' is not a member of `boost' /inc/boost/integer_fwd.hpp:70: error: template argument 1 is invalid /inc/boost/integer_fwd.hpp:73: error: `ulong_long_type' is not a member of `boost' /inc/boost/integer_fwd.hpp:73: error: `ulong_long_type' is not a member of `boost' /inc/boost/integer_fwd.hpp:73: error: template argument 1 is invalid /inc/boost/integer.hpp:20, inc/word_includes.hpp:34, /inc/word.hpp:34, /inc/boost/integer_traits.hpp:162: error: `long_long_type' is not a member of `boost' /boost/integer_traits.hpp:162: error: `long_long_type' is not a member of `boost' /inc/boost/integer_traits.hpp:163: error: template argument 1 is invalid /boost/integer_traits.hpp:163: error: explicit specialization of non-template `<type error>' /inc/boost/integer_traits.hpp:163: error: `long_long_type' is not a member of `boost' /inc/boost/integer_traits.hpp:163: error: `long_long_type' is not a member of `boost' /inc/boost/integer_traits.hpp:163: error: template argument 1 is invalid /inc/boost/integer_traits.hpp:164: error: `long_long_type' is not a member of `boost' /inc/boost/integer_traits.hpp:164: error: `long_long_type' is not a member of `boost' /inc/boost/integer_traits.hpp:165: error: template argument 1 is invalid /inc/boost/integer_traits.hpp:165: error: `<type error>' is not a valid type for a template constant parameter /inc/boost/integer_traits.hpp:165: error: `<type error>' is not a valid type for a template constant parameter /inc/boost/integer_traits.hpp:168: error: `ulong_long_type' is not a member of `boost' //inc/boost/integer_traits.hpp:168: error: `ulong_long_type' is not a member of `boost' /inc/boost/integer_traits.hpp:169: error: template argument 1 is invalid /inc/boost/integer_traits.hpp:169: error: explicit specialization of non-template `<type error>'

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boost program options future plans
by Aljaz 31 Jul '08

31 Jul '08

Hello Having an option to save-back configuration files would be a great feature of program option library. I've been wondering if there are any future plans for this? Also I have came across website http://code.google.com/p/clipo/ where idea for Clipo : Command Line Interpreter library based on the boost Program Option library is mentioned. This would be very useful as well. What do you think? Thanks for responses! Aljaz

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about shared_ptr and object_pool
by Ken zhang 31 Jul '08

31 Jul '08

Hi dear all. I have a class named "session" look like below code: class session : public boost::enable_shared_from_this< session >, private boost::noncopyable { public: session(boost::asio::io_service& io_service); ..... }; I want use boost::object_pool for allocate memory for session. class host { public: typedef boost::object_pool<session> session_pool; host() : new_session_( session_pool_.construct(), boost::bind(&session_pool::destroy, &session_pool_)) { } public: boost::shared_ptr< session > new_session_; session_pool session_pool_; }; but there has a compiler error was occured: 1> d:\development\boost_1_35_0\boost\bind.hpp(1613) : warning C4180: qualifier applied to function type has no meaning; ignored 1> d:\development\boost_1_35_0\boost\bind.hpp(1647) : see reference to class template instantiation 'boost::_bi::add_cref<Pm,I>' being compiled 1> with 1> [ 1> Pm=void (__thiscall boost::object_pool<session>::* )(session *), 1> I=1 1> ] 1> d:\development\coreframework\portal\src\portal_server.cpp(16) : see reference to class template instantiation 'boost::_bi::dm_result<Pm,A1>' being compiled 1> with 1> [ 1> Pm=void (__thiscall boost::object_pool<session>::* )(session *), 1> A1=portal_server::session_pool *__w64 1> ] 1>d:\development\boost_1_35_0\boost\mem_fn.hpp(318) : warning C4180: qualifier applied to function type has no meaning; ignored 1> d:\development\boost_1_35_0\boost\bind\bind_template.hpp(344) : see reference to class template instantiation 'boost::_mfi::dm<R,T>' being compiled 1> with 1> [ 1> R=void (session *), 1> T=boost::object_pool<session> 1> ] 1>Project : error PRJ0002 : Error result 1 returned from 'C:\Program Files\Microsoft Visual Studio 8\VC\bin\cl.exe'. I use Microsoft visual studio 8 (vs2005). Thanks all Best regards. Yours Kenneth.Sh

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boost::function, using undefined class?
by Erzengel Des Lichtes 31 Jul '08

31 Jul '08

Hello, I'm having an issue with boost::function in Visual Studio.NET 2005. In the following program: #include <boost/function.hpp> void SomeFunc(int* Blah) { //DoSomething } int __cdecl main(int argc, char* argv[], char* envp[]) { boost::function<void(*)(int*)> MyFunc; } I get the following error message: (Project Directory)\boostfunctest.cpp(11) : error C2079: 'MyFunc' uses undefined class 'boost::function' with [ Signature=void (__stdcall *)(int *) ] If I leave off the "(*)" it will compile, but this is just a simplified version of my real problem. The main reason this is a concern is I have a templated function that looks like this: template<typename Signature> boost::function<Signature> GetFunction(Signature ToCall); Which I intend to use to record and "play back" certain function calls. However, when it sees the signiture from the function pointer, it ALWAYS sees it as 'void(*)(int*)' (for example), rather than 'void(int*)' and fails to compile. For example, the following program: #include <boost/function.hpp> void SomeFunc(int* Blah) { //DoSomething } template<typename Signature> boost::function<Signature> GetFunction(Signature ToCall) { //TODO: Check if function is in list, add it to list, etc. return boost::function<Signature>(ToCall); } int __cdecl main(int argc, char* argv[], char* envp[]) { GetFunction(SomeFunc); } I get: (Project Directory)\boostfunctest.cpp(17) : error C2027: use of undefined type 'boost::function' with [ Signature=void (__stdcall *)(int *), Allocator=std::allocator ] So, anyone have any idea what's wrong and how to fix it? Thanks for any help. Note: I am compiling with /Gz, but compiling with /Gd and /Gr merely changes the "__stdcall" to "__cdecl" and "__fastcall" in the error messages, respectively, so it does not seem to matter which calling convention is used. -- Erzengel des Lichtes 光の大天使 (Hikari no Daitenshi) Archangel of Light

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Passing Mutexes
by Simon Pickles 31 Jul '08

31 Jul '08

Hi, I am trying to implement a simple producer/consumer system with two or more threads. The main thread has a consumer class which creates producers. These producers perform synchronous blocking operations then post their outcome into a std::vector of results which was passed from the main consumer. class consumer { public: consumer() { m_results = boost::shared_ptr<std::vector<result> >( new std::vector<result> ); new producer( m_results, m_mutex ); // do a single task and put result in m_results } void Process() { result r; { boost::mutex::scoped_lock lock(m_mutex); r = m_results.pop.front(); } // Do stuff with r } private: boost::mutex m_mutex; boost::shared_ptr<std::vector<result> > m_results; }; class producer { producer( boost::shared_ptr<std::vector<result> > results, boost::mutex& mtx ) { boost::thread( boost::bind( &DoInThread, this, results, mtx ) ); // actually uses a threadpool but not relevant here. } void DoInThread( boost::shared_ptr<std::vector<result> > results, boost::mutex& mtx ) { result r; // do long async op and store in r boost::mutex::scoped_lock lock(mtx); results->push_back(r); } }; /////////////// I am trying to share a single mutex with both producer and consumer. However I get a noncopyable error, even if I pass a reference. Can anyone point out what the correct approach is? Thanks Simon

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Re: [Boost-users] Array to List
by noman javed 31 Jul '08

31 Jul '08

Actually I am working on numerical data.

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Xpressive and line breaks
by Simon Steele 30 Jul '08

30 Jul '08

Hi, I think there's a bug in Xpressive in Boost 1.35 with newline handling. Here is a very simple example: Subject: abc\ndef\nghi Regex: ^.+$ I'm looking for "abc". The following xpressive-based code has odd results: string text(argv[1]); sregex rex = sregex::compile(text, regex_constants::not_dot_newline); smatch match; string subject("abc\ndef\nghi"); if (regex_search(subject.begin(), subject.end(), match, rex, regex_constants::match_default)) { std::cout << "Match at: " << match.position(0) << " length: " << match.length(0); } ^.+$: Match at: 8 length: 3 $: Match at: 4 length: 0 .$: Match at: 10 length: 1 These definitely aren't right, it appears that the only place where end-of-line is matching is at end-of-string. Things get even stranger if I try to use Windows or Mac style end-of-line characters which I need to support too. If I use boost::regex instead then I get these results: ^.+$: Match at: 0 length: 3 $: Match at: 3 length: 0 .$: Match at: 2 length: 1 These are the results I'd expect. It appears in Xpressive that the check in assert_line_base::is_line_break is broken, the following line: if(traits_cast<Traits>(state).isctype(ch, this->newline_)) checks the previous character to see if it's a line break. I believe this should check the current character: if(traits_cast<Traits>(state).isctype(*state.cur_, this->newline_)) This then gets me sane results: ^.+$: Match at: 0 length: 3 $: Match at: 3 length: 0 .$: Match at: 2 length: 1 Is this a known bug? Thanks, Simon.

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