May 2008 - Boost-users - lists.boost.org

boost::bind and shared pointers
by Alejandro Martínez 15 May '08

15 May '08

I have this problem. Im using boost::bind for programming the call-back mechanism for a gui system and to pass messages (possibly, delayed messages). My problem is, that when i bind member functions, if i specify the instance of the class as a shared_ptr, then i get memory leaks because the binding's shared_ptr to the instance keeps it alive, and it potentially produces cyclic references that in the current model, would be complicated to break. And of course, if i use raw pointers to the binding instances, then i'll get a crash if the instance has been destroyed and i try to execute the binding function. So what i would need, is to use bind with weak pointers, and just do nothing if locking it fails. I'm not sure how to do that, or how to assemble a good walkaround. I'd like it to be as automatic as possible. Thanks for your time, i appreciate any help :)

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Question on how to build Date_Time libraries to static linking
by Adolfo Jimenez 14 May '08

14 May '08

Hi list: After a couple years with success in using the Boost Date_Time library in Windows with minGW, now y need port the application to MS Visual C++ (actually using 2008 Express edition C++ 9.0). I downloaded the Boost 1.35.0 version, and generated the binary files with this command: bjam release debug threading=multi --toolset=msvc stage The documentation states that, in this case, the names for the libraries to static linking respond to the structure: "libboost_date_time-xxxx.lib" and that the definition libraries respond to the schema "boost_date-time-xxx.lib". In fact, along with some DLLs, I have obtained some .LIB files: boost_date_time-vc90-mt-1_35.lib boost_date_time-vc90-mt.lib boost_date_time-vc90-mt-gd-1_35.lib boost_date_time-vc90-mt-gd.lib but only four libboost_xxx.lib: libboost_test_exec_monitor-vc90-mt-1_35.lib libboost_test_exec_monitor-vc90-mt.lib libboost_test_exec_monitor-vc90-mt-gd-1_35.lib libboost_test_exec_monitor-vc90-mt-gd.lib I want use static linking with the library, so the compiler complain when looking for the file libboost_date_time-vc90-mt-gd-1_35.lib The question is: Some idea on how to get that file? Thanks.

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Problem compiling against boost on AIX using xlC
by Rich Cook 14 May '08

14 May '08

Hello, I have a need to try to compile boost_1_35_0 using xlC. I am getting the following error from my attempt, and I cannot find anything on google about it. Is there an environment variable or compiler flag I ought to be using with boost? Thank you. xlC -c -O2 -I../ -I/g/g0/rcook/aix_5_64_fed/include -I.. -I/usr/ gapps/visus/devel/rcook/visus/up-gcc/include -I../ -I/g/g0/rcook/ aix_5_64_fed/include -I.. -I/usr/gapps/visus/devel/rcook/visus/up- gcc/include -DNO_SETBUF -I../RC_cpp_lib/aix_5_64_fed/boost_1_35_0 - DDEBUG_TO_STDERR -O2 MirandaReader.C -o aix_5_64_fed/MirandaReader.o "../RC_cpp_lib/aix_5_64_fed/boost_1_35_0/boost/optional/ optional.hpp", line 434.66: 1540-0217 (S) "T" is not a member of "locale". "../RC_cpp_lib/aix_5_64_fed/boost_1_35_0/boost/optional/ optional.hpp", line 434.10: 1540-0700 (I) The previous message was produced while processing "boost::optional_detail::optional_base<std::locale>::destroy_impl (is_not_reference_tag)". "../RC_cpp_lib/aix_5_64_fed/boost_1_35_0/boost/optional/ optional.hpp", line 522.5: 1540-0700 (I) The previous message was produced while processing "boost::optional<std::locale>::~optional()". "../RC_cpp_lib/aix_5_64_fed/boost_1_35_0/boost/optional/ optional.hpp", line 454.7: 1540-0700 (I) The previous message was produced while processing "boost::optional<std::locale>::__dftdt()". "../RC_cpp_lib/aix_5_64_fed/boost_1_35_0/boost/format/ format_implementation.hpp", line 60.5: 1540-0700 (I) The previous message was produced while processing "boost::basic_format<char,std::char_traits<char>,std::allocator<char> >::basic_format(const string_type &)". "MirandaReader.C", line 382.6: 1540-0700 (I) The previous message was produced while processing "MirandaReader::GetGridOrigin(long, Point<double> &)". gmake: *** [aix_5_64_fed/MirandaReader.o] Error 1 -- ✐Richard Cook ✇ Lawrence Livermore National Laboratory Bldg-453 Rm-4037, Mail Stop L-557 7000 East Avenue, Livermore, CA, 94550, USA ☎ (office) (925) 423-9605 ☎ (fax) (925) 423-6961 --- Information Management & Graphics Grp., Services & Development Div., Integrated Computing & Communications Dept. (opinions expressed herein are mine and not those of LLNL)

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Boost.Python: Wrapping functions with std::ostream & and std::istream & arguments
by Bilokon, Paul 14 May '08

14 May '08

Hi, I reckon the subject expresses my question pretty well. Is it possible to wrap C++ functions that take std::ostream & and std::istream & arguments? How can I convert the corresponding Python objects? Are there any examples? Many thanks! Best wishes, Paul - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - This message is intended only for the personal and confidential use of the designated recipient(s) named above. If you are not the intended recipient of this message you are hereby notified that any review, dissemination, distribution or copying of this message is strictly prohibited. This communication is for information purposes only and should not be regarded as an offer to sell or as a solicitation of an offer to buy any financial product, an official confirmation of any transaction, or as an official statement of Lehman Brothers. Email transmission cannot be guaranteed to be secure or error-free. Therefore, we do not represent that this information is complete or accurate and it should not be relied upon as such. All information is subject to change without notice.

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Dynamic parser?
by Hansi 14 May '08

14 May '08

Hello, I have a question. I need a parser which i can generate dynamically. e.g. I have to parse a xml or header file which I get from someone. Now I want to read this file (e.g. with spirit) and generate inside the running program an parser (it should be used to display information which is send and received over different I/O) Is this possible with spirit? Is there somewhere an example? Best regards Hansjörg

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Re: [Boost-users] boost.bind: nested bind fails
by gfsdjkgf＠Safe-mail.net 14 May '08

14 May '08

> > Wrap Handler in boost::protect. For lambda use boost::lambda::protect > > bind(&Test2<Handler_t>, boost::protect(Handler))(); > > Sorry, but this does not work. 1>d:\projekte\libs\boost_1_35\build\x86\include\boost-1_35\boost\bind.hpp(232) : error C2664: 'void (Handler_t)' : cannot convert parameter 1 from 'boost::_bi::protected_bind_t<F>' to 'boost::_bi::bind_t<R,F,L>' 1> with 1> [ 1> Handler_t=boost::_bi::bind_t<void,void (__cdecl *)(int),boost::_bi::list1<boost::_bi::value<int>>> 1> ] 1> and 1> [ 1> F=boost::_bi::bind_t<void,void (__cdecl *)(int),boost::_bi::list1<boost::_bi::value<int>>> 1> ] 1> and 1> [ 1> R=void, 1> F=void (__cdecl *)(int), 1> L=boost::_bi::list1<boost::_bi::value<int>> 1> ] 1> No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called 1> d:\projekte\libs\boost_1_35\build\x86\include\boost-1_35\boost\bind\bind_template.hpp(20) : see reference to function template instantiation 'void boost::_bi::list1<A1>::operator ()<void(__cdecl *)(Handler_t),boost::_bi::list0>(boost::_bi::type<T>,F &,A &,int)' being compiled 1> with 1> [ 1> A1=boost::_bi::value<boost::_bi::protected_bind_t<boost::_bi::bind_t<void,void (__cdecl *)(int),boost::_bi::list1<boost::_bi::value<int>>>>>, 1> Handler_t=boost::_bi::bind_t<void,void (__cdecl *)(int),boost::_bi::list1<boost::_bi::value<int>>>, 1> T=void, 1> F=void (__cdecl *)(boost::_bi::bind_t<void,void (__cdecl *)(int),boost::_bi::list1<boost::_bi::value<int>>>), 1> A=boost::_bi::list0 1> ] 1> d:\projekte\libs\boost_1_35\build\x86\include\boost-1_35\boost\bind\bind_template.hpp(18) : while compiling class template member function 'void boost::_bi::bind_t<R,F,L>::operator ()(void)' 1> with 1> [ 1> R=void, 1> F=void (__cdecl *)(boost::_bi::bind_t<void,void (__cdecl *)(int),boost::_bi::list1<boost::_bi::value<int>>>), 1> L=boost::_bi::list1<boost::_bi::value<boost::_bi::protected_bind_t<boost::_bi::bind_t<void,void (__cdecl *)(int),boost::_bi::list1<boost::_bi::value<int>>>>>> 1> ] 1> d:\projekte\test2\main.cpp(14) : see reference to class template instantiation 'boost::_bi::bind_t<R,F,L>' being compiled 1> with 1> [ 1> R=void, 1> F=void (__cdecl *)(boost::_bi::bind_t<void,void (__cdecl *)(int),boost::_bi::list1<boost::_bi::value<int>>>), 1> L=boost::_bi::list1<boost::_bi::value<boost::_bi::protected_bind_t<boost::_bi::bind_t<void,void (__cdecl *)(int),boost::_bi::list1<boost::_bi::value<int>>>>>> 1> ] 1> d:\projekte\test2\main.cpp(23) : see reference to function template instantiation 'void Test1<boost::_bi::bind_t<R,F,L>>(Handler_t)' being compiled 1> with 1> [ 1> R=void, 1> F=void (__cdecl *)(int), 1> L=boost::_bi::list1<boost::_bi::value<int>>, 1> Handler_t=boost::_bi::bind_t<void,void (__cdecl *)(int),boost::_bi::list1<boost::_bi::value<int>>> 1> ]

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boost.bind: nested bind fails
by gfsdjkgf＠Safe-mail.net 14 May '08

14 May '08

Hello, let's come straight to the code. I am not sure why it fails (both boost::bind and boost::lambda::bind fail). I use Visual Studio 9 (2008, x86) and boost 1.35 (retail). What's wrong? #include <boost/bind.hpp> using boost::bind; //#include <boost/lambda/bind.hpp> //using boost::lambda; template<class Handler_t>void Test2(Handler_t Handler) { } template<class Handler_t>void Test1(Handler_t Handler) { bind(&Test2<Handler_t>, Handler)(); } void TestFunc(int i) { } int main() { Test1(bind(TestFunc,0)); } 1>d:\projekte\libs\boost_1_35\build\x86\include\boost-1_35\boost\bind.hpp(232) : error C2664: 'void (Handler_t)' : cannot convert parameter 1 from 'void' to 'boost::_bi::bind_t<R,F,L>' 1> with 1> [ 1> Handler_t=boost::_bi::bind_t<void,void (__cdecl *)(int),boost::_bi::list1<boost::_bi::value<int>>> 1> ] 1> and 1> [ 1> R=void, 1> F=void (__cdecl *)(int), 1> L=boost::_bi::list1<boost::_bi::value<int>> 1> ] 1> Expressions of type void cannot be converted to other types 1> d:\projekte\libs\boost_1_35\build\x86\include\boost-1_35\boost\bind\bind_template.hpp(20) : see reference to function template instantiation 'void boost::_bi::list1<A1>::operator ()<void(__cdecl *)(Handler_t),boost::_bi::list0>(boost::_bi::type<T>,F &,A &,int)' being compiled 1> with 1> [ 1> A1=boost::_bi::bind_t<void,void (__cdecl *)(int),boost::_bi::list1<boost::_bi::value<int>>>, 1> Handler_t=boost::_bi::bind_t<void,void (__cdecl *)(int),boost::_bi::list1<boost::_bi::value<int>>>, 1> T=void, 1> F=void (__cdecl *)(boost::_bi::bind_t<void,void (__cdecl *)(int),boost::_bi::list1<boost::_bi::value<int>>>), 1> A=boost::_bi::list0 1> ] 1> d:\projekte\libs\boost_1_35\build\x86\include\boost-1_35\boost\bind\bind_template.hpp(18) : while compiling class template member function 'void boost::_bi::bind_t<R,F,L>::operator ()(void)' 1> with 1> [ 1> R=void, 1> F=void (__cdecl *)(boost::_bi::bind_t<void,void (__cdecl *)(int),boost::_bi::list1<boost::_bi::value<int>>>), 1> L=boost::_bi::list1<boost::_bi::bind_t<void,void (__cdecl *)(int),boost::_bi::list1<boost::_bi::value<int>>>> 1> ] 1> d:\projekte\test2\main.cpp(13) : see reference to class template instantiation 'boost::_bi::bind_t<R,F,L>' being compiled 1> with 1> [ 1> R=void, 1> F=void (__cdecl *)(boost::_bi::bind_t<void,void (__cdecl *)(int),boost::_bi::list1<boost::_bi::value<int>>>), 1> L=boost::_bi::list1<boost::_bi::bind_t<void,void (__cdecl *)(int),boost::_bi::list1<boost::_bi::value<int>>>> 1> ] 1> d:\projekte\test2\main.cpp(22) : see reference to function template instantiation 'void Test1<boost::_bi::bind_t<R,F,L>>(Handler_t)' being compiled 1> with 1> [ 1> R=void, 1> F=void (__cdecl *)(int), 1> L=boost::_bi::list1<boost::_bi::value<int>>, 1> Handler_t=boost::_bi::bind_t<void,void (__cdecl *)(int),boost::_bi::list1<boost::_bi::value<int>>> 1> ]

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How to obtain vertex pointer (not descriptor) of vertex created with add_vertex.
by Ananth Durbha 14 May '08

14 May '08

Hi, I am trying to modify a set of file parser callback functions (for a custom file format) to populate a Boost graph. The callbacks provide a (void*) pointer style parameter passing. But Boost graph method add_vertex(graph) will return a vertex descriptor. How do I obtain the pointer information for this newly added vertex so that the pointer can be cast as (void*) and passed to the appropriate call back? Thanks, Ananth

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using boost.regex on submatches.
by Dan Smithers 14 May '08

14 May '08

Hi, I have a problem using boost.regex to parse a message. The message contains an unknown number of handles terminated by a tab. Each handle has four hex digits. To find the block of handles I use a regex search and then I want to use an iterator to split up the block. #include <iostream> #include <boost/regex.hpp> #include <string> int main (int argc, char *argv[]) { std::string input("HEAD123456789abcdef0\t"); try { std::cout << "creating regex" << std::endl; boost::regex reg("^HEAD(([a-fA-F0-9]{4})+)\\t"); boost::smatch sm; std::cout << "searching " << input << std::endl; boost::regex_search(input, sm, reg); boost::sregex_iterator end; boost::regex handles("([a-fA-F0-9]{4})"); boost::sregex_iterator it(sm[1].str().begin(), sm[1].str().end(), handles); while (it != end) { std::cout << *it++ << std::endl; } } catch (...) { std::cout << "Exception" << std::endl; } } I get a segmentation fault if I run this - sometimes with a memory exhausted notice. If I replace the iterator line boost::sregex_iterator it(sm[1].str().begin(), sm[1].str().end(), handles); with const string& hs(sm[1].str()); boost::sregex_iterator it(hs.begin(), hs.end(), handles); then everything seems to work. What's going on here? Is there a simpler way of achieving this? thanks dan

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Tribool issue with logical operators && and ||
by Jean-Pierre Bergamin 14 May '08

14 May '08

Hello boost-users I just ran into quite a bad issue with boost::tribool. The overloaded operators && and || may (and normally do) evaluate the righthand side of logical expressions although not needed/permitted. They i.e. evaluate the rhs expression in a conjunction where the first term is false. This leads of course to very surprising results. IMHO, the provided operators should be removed or should honor normal semantics. Shall I issue a bug-report? I think the current situation is quite unconvincingly. Regards James

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