March 2005 - Boost-users - lists.boost.org

when to use libboost_xxx-mt ?
by Oliver Kowalke 11 Mar '05

11 Mar '05

Hello, afaik '-mt' stands for multithreading. Do I've to link against the '-mt' version of a boost library if my application is single threaded but uses external libs which internally span threads? Could you be so kind to give me a generall guideline? thx Oliver -- SMS bei wichtigen e-mails und Ihre Gedanken sind frei ... Alle Infos zur SMS-Benachrichtigung: http://www.gmx.net/de/go/sms

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Serialization, multiple inheritance, bad cast at smart_cast.hpp:202
by Zoltan Szatmary 11 Mar '05

11 Mar '05

Dear all I use the serialization library of boost, and I am very satisfied with it except one annoying issue. It turns out, that in many cases (not always!!!) when there is a multiple inheritance structure in the class hierarchy I am trying to serialize I get a std::bad_cast exception at line 202 in smart_cast.hpp. The corresponding boost code is: template<class U> static T cast(U * u){ T tmp = dynamic_cast<T>(u); #ifndef NDEBUG if ( tmp == 0 ) throw std::bad_cast(); #endif return tmp; } I have debugged it, and I could not really find out what the problem was. For example I have a class hierarchy similar to this: class A class B : public A class C : public virtual B class D : public virtual B class E : public C, public D so, a classic diamond inheritance which the serialization lib is supposed to be able to tackle with. Now, if I have a piece of code like this boost::serialization::xml_oarchive oa(somestream); A *a = new E(); oa << BOOST_SERIALIZATION_NVP(a); it throws exception at the aforementioned line. Examining the template substitutions, template class T is substituted with const B* and template class U is substituted with const A. So, the program should do a downcast on a const A* to const B* which is ought to be possible. The funny thing is, that the error does not always appear! I could put together a simple example code demonstrating this effect, but I am not sure that attachments to this mail get through the list server, so anybody kind enough to take a look at this problem can ask me to send him/her the example code. I have tested the example code both with Intel C++ compiler v8.1 and G++, so I concluded this may not be a compiler error but rather some boost flaw. Any help is warmly welcome and thanked in advance! Cheers Zoltan

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PC-Lint and boost 1.32.0
by Jarl Lindrud 10 Mar '05

10 Mar '05

Hi! Is anyone here running PC-Lint successfully on projects using Boost 1.32.0 ? When I run it (PC-Lint 8.00q), it winds up in an infinite loop while processing some headers from boost/mpl. There's a note about it on Gimpel's discussion boards, but no responses from them, unfortunately... Is anyone else having this problem? TIA! /Jarl

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Boost threads libraries? linking problem and question
by Roger Wilco 10 Mar '05

10 Mar '05

I have a large (at least non-trivial) C++ application that uses Boost threads. I am now trying to get it building as a Managed C++ (aka C++ .NET) application. The original unmanaged MFC application used the following import library: ..\boost\boost_1_32_0\bin\boost\libs\thread\build\boost_thread.dll\vc-7_1\release\threading-multi\boost_thread-vc71-mt-gd-1_32.lib The managed C++ Forms application requires that AND a second library which seems to be a static library and not an import library for a DLL: ..\boost\boost_1_32_0\bin\boost\libs\thread\build\libboost_thread.lib\vc-7_1\debug\runtime-link-static\threading-multi\libboost_thread-vc71-mt-sgd-1_32.lib It seems wrong that I need two Boost thread libraries to build with. Hoewver, my project won't build without both. There are apparently some #pragma-like instructions in the Boost source that trigger the linking of these libraries. If I do link with both Boost thread libraries, the project builds but gets bizarre exceptions at runtime that are buried in non-debuggable code. What is the difference between those Boost libraries? Which one is the one that I want? How can I stop the linker directives in the code from including the library that I shouldn't be using?

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Re: boost::bind problems with __cdecl and MSVC
by Daniel Boelzle 10 Mar '05

10 Mar '05

Hello Peter, > This can only happen if your default calling convention is something > other than __cdecl. This is very rare and boost::bind does not provide > explicit support for __cdecl, relying on it being the default. I am not forcing any specific calling convention: no /Gz (stdcall), /Gr (fastcall), nor /Gd (__cdecl) on my command line. MSDN documents that __cdecl is the default for vararg member functions, but thiscall for non-vararg member functions. The reason for decorating member functions with __cdecl is to get independent of the above mentioned switches when including those header files (thiscall cannot be specified, no keyword). regards, --Daniel

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Boost Unit Test with VC 7.1
by DrJekyll 09 Mar '05

09 Mar '05

Dear list member I have the problem with Unit Test. I am just creat new project file and copy the code from the start page http://www.boost.org/libs/test/doc/components/utf/getting_started/index.html but it does not compiled. I think the problem come from the work space configuration but I dont know exactly which point. Could someone share with me his experience on this matter? Best regards XS

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[Foreach] Trouble iterating over Boost.MultiIndex containers
by Eelis van der Weegen 09 Mar '05

09 Mar '05

I'm having trouble using BOOST_FOREACH to iterate over Boost.MultiIndex containers. I've attached a testcase, which fails to compile because of what looks like an ADL collision between range_iterator's end() and boost::mpl::end. I'm using GCC 3.4.2 with foreach.hpp revision 1.22 from the sandbox. Others have reported that GCC 4.0.0 20050130 is also affected. (I'm aware that BOOST_FOREACH isn't part of Boost yet, but it's in the review queue so I thought posting this here was appropriate.) Regards, Eelis #include <boost/multi_index/sequenced_index.hpp> #include <boost/multi_index_container.hpp> #include <boost/foreach.hpp> namespace mi = boost::multi_index; typedef boost::multi_index_container<int, mi::indexed_by<mi::sequenced<> > > C; void f (C const & c) { for (C::const_iterator i = c.begin(); i != c.end(); ++i) { int r = *i; } // ok BOOST_FOREACH(int r, c) {} // errors }

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boost::bind problems with __cdecl and MSVC
by Daniel Boelzle 09 Mar '05

09 Mar '05

Hello, I have problems using wonderful boost::bind with __cdecl member functions like the following: #include <boost/bind.hpp> struct S { void __cdecl foo( int ); }; void bar() { S s; int const n = 5; boost::bind( &S::foo, &s, _1 )( n ); } ... error C2825: 'F::result_type': cannot form a qualified name ... I am using MSVC Version 13.10.3077 and boost 1.32.0. I know there is already a way to use stdcall, so does anybody see a solution for __cdecl? thanks for any help, regards, --Daniel

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[filesystem] VC 8.0, AMD64
by Cory Nelson 09 Mar '05

09 Mar '05

I'm using the March 2005 CTP beta of VS2005, and building for AMD64. I'm getting these errors with filesystem (fresh from CVS): boost\config\abi_prefix.hpp(19) : error C2220: warning treated as error - no 'object' file generated boost\config\abi_prefix.hpp(19) : warning C4103: 'boost\config\abi_prefix.hpp' : alignment changed after including header, may be due to missing #pragma pack(pop) boost\filesystem\path.hpp(20) : warning C4103: 'boost\filesystem\path.hpp' : alignment changed after including header, may be due to missing #pragma pack(pop) boost\config\abi_suffix.hpp(20) : warning C4103: 'boost\config\abi_suffix.hpp' : alignment changed after including header, may be due to missing #pragma pack(pop) boost\filesystem\path.hpp(170) : warning C4103: 'boost\filesystem\path.hpp' : alignment changed after including header, may be due to missing #pragma pack(pop) boost\config\abi_prefix.hpp(19) : warning C4103: 'boost\config\abi_prefix.hpp' : alignment changed after including header, may be due to missing #pragma pack(pop) boost\filesystem\fstream.hpp(21) : warning C4103: 'boost\filesystem\fstream.hpp' : alignment changed after including header, may be due to missing #pragma pack(pop) boost\config\abi_suffix.hpp(20) : warning C4103: 'boost\config\abi_suffix.hpp' : alignment changed after including header, may be due to missing #pragma pack(pop) boost\filesystem\fstream.hpp(190) : warning C4103: 'boost\filesystem\fstream.hpp' : alignment changed after including header, may be due to missing #pragma pack(pop) -- Cory Nelson http://www.int64.org

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Re: Re: boost::program options question. Implicit()
by Alexis H. Rivera-Rios 09 Mar '05

09 Mar '05

>I think it's the library. But in any case, I plan to >remove the >'implicit' >flag in 1.33. Why do you want it? What about: > > desc.add_options() > ("debug", bool_option(), "enable debugging") > >? >- Volodya Why do I wanted? No special reason, I was learning to use the library and got stuck on that one. The code didn't do what the documentation said it should do. I wasn't aware of the bool_option. Will that let me do something like myprogram --debug or will I have to do something like myprogram --debug=1 ? Thanks, Alexis Programming Tutorial: In Python: To do this, do this In Perl: To do this, do this or this or this or this... In C: To do this, do this, but be careful In C++: To do this, do this, but don't do this, be careful of this, watch out for this, and whatever you do, don't do this __________________________________ Celebrate Yahoo!'s 10th Birthday! Yahoo! Netrospective: 100 Moments of the Web http://birthday.yahoo.com/netrospective/

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