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simple_ls compile error
by Tord Holmqvist 31 May '05

31 May '05

Just tried to install boost on my laptop and I can't seem to get it to work. (slack 10.1) installed it with bjam "-sTOOLS=gcc" install and it seems to have added itself in /usr/local/include and so on. but when I try to build simple_ls.cpp I only get: todelod@todelod2:~/hemma/my_little_project$ gcc simple_ls.cpp -lboost_filesystem /usr/lib/gcc-lib/i486-slackware-linux/3.3.4/../../../../i486-slackware-linux/bin/ld: cannot find -lboost_filesystem collect2: ld returned 1 exit status what am I doing wrong?? (going mad...) /t

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numeric/conversion library question
by Toon Knapen 31 May '05

31 May '05

Following small program does not give the expected result. It prints some big negative value if compiled with my gcc 3.4.3 on linux or intel-linux 8.1. However commenting out either (one suffices) of the commented out lines makes it work correctly. I don't understand what is happening here, can anybody what is wrong with this function 'convert' or is the use of the conversion library wrong? <code> #include <boost/numeric/conversion/cast.hpp> #include <iostream> template<typename Target, typename Source> inline typename ::boost::numeric::converter<Target,Source>::result_type //convert ( const Source& arg ) // using this signatures makes it work convert ( Source arg ) { return ::boost::numeric::converter< Target, Source >::convert( arg ) ; } // { Target temp = ::boost::numeric::converter< Target, Source >::convert( arg ) ; return temp ; } int main() { int big = 900 ; ptrdiff_t diff = 16 ; std::cout << std::min( big, convert< int >( diff ) ) << std::endl ; return 0 ; } </code>

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Questions about Boost.ProgramOptions
by Elisha Berns 31 May '05

31 May '05

Hi, I have a few questions about Boost.ProgramOptions pertaining to parsing an argv that is of wchar_t data type. The first thing that isn't clear from the examples is whether it's possible at all. The second thing that isn't clear is how to do it and store string values in std::wstring variables. Here are the specifics: 1) How do you use program_options with an argv argument that is a wchar_t data type? Like this? variables_map vm; store(parse_command_line<wchar_t>(argc, argv, desc), vm); but then the question is how do you store any of the command line values in wstring variables? Like this? options_description desc("allowed options"); desc.add_options() // First parameter describes option name/short name // The second is parameter to option // The third is description ("help,h", "print usage message") ("validate,v", value(&strFile), "validate xml file"); // strFile is a wstring Well that doesn't work. 2) I am getting 3 link errors when trying the above: ToolsTest.obj : error LNK2019: unresolved external symbol "void __cdecl boost::program_options::store(class boost::program_options::basic_parsed_options<unsigned short> const &,class boost::program_options::variables_map &)" (?store@program_options@boost@@YAXABV?$basic_parsed_options@G@12@AAVvari ables_map@12@@Z) referenced in function _main ToolsTest.obj : error LNK2019: unresolved external symbol "public: __thiscall boost::program_options::basic_parsed_options<unsigned short>::basic_parsed_options<unsigned short>(class boost::program_options::basic_parsed_options<char> const &)" (??0?$basic_parsed_options@G@program_options@boost@@QAE@ABV?$basic_parse d_options@D@12@@Z) referenced in function "public: class boost::program_options::basic_parsed_options<unsigned short> __thiscall boost::program_options::basic_command_line_parser<unsigned short>::run(void)const " (?run@?$basic_command_line_parser@G@program_options@boost@@QBE?AV?$basic _parsed_options@G@23@XZ) ToolsTest.obj : error LNK2019: unresolved external symbol "class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > __cdecl boost::program_options::to_internal(class std::basic_string<unsigned short,struct std::char_traits<unsigned short>,class std::allocator<unsigned short> > const &)" (?to_internal@program_options@boost@@YA?AV?$basic_string@DU?$char_traits @D@std@@V?$allocator@D@2@@std@@ABV?$basic_string@GU?$char_traits@G@std@@ V?$allocator@G@2@@4@@Z) referenced in function "class std::vector<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,class std::allocator<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > > > __cdecl boost::program_options::to_internal<class std::basic_string<unsigned short,struct std::char_traits<unsigned short>,class std::allocator<unsigned short> > >(class std::vector<class std::basic_string<unsigned short,struct std::char_traits<unsigned short>,class std::allocator<unsigned short> >,class std::allocator<class std::basic_string<unsigned short,struct std::char_traits<unsigned short>,class std::allocator<unsigned short> > > > const &)" (??$to_internal@V?$basic_string@GU?$char_traits@G@std@@V?$allocator@G@2@ @std@@@program_options@boost@@YA?AV?$vector@V?$basic_string@DU?$char_tra its@D@std@@V?$allocator@D@2@@std@@V?$allocator@V?$basic_string@DU?$char_ traits@D@std@@V?$allocator@D@2@@std@@@2@@std@@ABV?$vector@V?$basic_strin g@GU?$char_traits@G@std@@V?$allocator@G@2@@std@@V?$allocator@V?$basic_st ring@GU?$char_traits@G@std@@V?$allocator@G@2@@std@@@2@@3@@Z) Thanks for any help here, Elisha Berns e.berns(a)computer.org tel. (310) 556 - 8332 fax (310) 556 - 2839

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Re: Re: Serialization when using virtual inheritance
by Eric 30 May '05

30 May '05

Thanks Robert. This partially worked... Your comment about putting the BOOST_CLASS_EXPORT macro into the header keyed me into something. I am using the BOOST_CLASS_EXPORT(derived) macro, but I've been placing them into the source (cpp) file instead of the header (h) file. With my system, when I put BOOST_CLASS_EXPORT(derived) into the header file, I get a multiply-defined error at link time (the offending code is boost::archive::detail::guid_initializer<class,...> since the header is included multiple times when I use the class. As a test, I setup a sandbox with a stripped down system and was able to get it to work when I put the BOOST_CLASS_EXPORT in the header, but not when it is in the cpp file. Q: Why does the location of the BOOST_CLASS_EXPORT matter? Is it doing order-depended initialization upon bringing up the system? Q: How do I avoid the mutiple defined error in the linker? Thanks again for your help and the library :) -Eric

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Re: date time library question !!
by Saurabh Sood 30 May '05

30 May '05

thanks. Both work but i might finally decide in favor lexical_cast -ss

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Serialization when using virtual inheritance
by Eric 29 May '05

29 May '05

Boost version: 1.32.0 I am trying to use the serialization class to serialize data pointed to by the virtual base class. Note that the code works great if I don't use virtual inheritance off of the base class. Here is a quick run-down of the hierarchy and code: class Base { virtual void OneOfManyVirtuals() = 0; // Serialization Interface template<class Archive> void serialize(Archive &ar, const unsigned int version) { //empty } }; BOOST_IS_ABSTRACT(Base); class Derived : virtual public Base { virtual void OneOfManyVirtuals() { } // Serialization Interface template<class Archive> void serialize(Archive &ar, const unsigned int version) { //empty ar & BOOST_SERIALIZATION_BASE_OBJECT_NVP(Base); } } // later in the main code Base* pBase = new Derived; boost::archive::xml_oarchive oa(ofs); // doesn't work oa << BOOST_SERIALIZATION_NVP(pBase); // works oa << BOOST_SERIALIZATION_NVP(*pBase); When if fails, it fails in the oseralizer.hpp at line 419 with the comment: // convert pointer to more derived type. if this is thrown // it means that the base/derived relationship hasn't be registered I tried registering the pairs with void_cast_register, but I wasn't successful. Any real examples of how to use this method would be appreciated. So, does anyone know why the pointer to the base doesn't work when using virtual inheritance? It works find when I remove the virtual from the inheritance. Unfortunately, with the software architecture that I have, there are several cases when the virtual inheritance off of interfaces is required. Any help with the matter is greatly appreciated. -Eric

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date time library question !!
by Saurabh Sood 29 May '05

29 May '05

Hi all, i am totally new to boost but more i am feeling good and bad at same time ... good coz boost is cross-platform and powerful .. however sometimes its hard to do simple things ... Take following for instance .. ------------------------------------------------------------------------------------- using namespace boost::posix_time; ptime p = = microsec_clock::local_time(); ... ... (some calculations) ... time_duration td = microsec_clock::local_time() - p; std::cout << std::string(" Total Milliseconds: ") << td.total_milliseconds() << std::endl; // Works fine ------------------------------------------------------------------------------------- But how can the value present in td.total_milliseconds() could be put inside a std::string ? It might sound simple but i guess its tricky . ... thanks for the reply in advance. cheers saurabh

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boost::thread() calls destructor!!
by Ricky Corsi 28 May '05

28 May '05

Hello, I tried to modify the sample code from Bill Kempf for boost.thread, listing 4 that I got at the following link http://www.cuj.com/documents/s=8470/cuj0205kempf/list4.htm to embed the write function in a writeClass function-object. That is a test because in a program I need to pass a function object to one thread, and not a global function. I simply wrote this code: class writerClass { public: ~writerClass() { // for Debug std::cout << "writerClass dtor" << std::endl; } void operator() () { for (int n = 0; n < ITERS; ++n) { { boost::mutex::scoped_lock lock(io_mutex); std::cout << "sending: " << n << std::endl; } buf.put(n); } } }; and changed in the main() --> boost::thread thrd2(&writer); with --> boost::thread thrd2((writerClass())); Everything works the same, but I have the destructor of wirterClass called 4 times, when constructing thrd2!!! That's weird to me, but it's annoying because in my other program, the dtor destroys some member data, and the program crashes because of it. Why is the ~writerClass() called? is there maybe some exception thrown?? how can I solve the problem? thank you ricky P.S. if it can be useful, during the compilation I get a warning (MSVC 7.1), but I read that it can be safely ignored: warning C4275: non dll interface class "boost::noncopyable_::noncopyable" used as a base for dll interface class "boost::mutex" [...]\boost\noncopyable.hpp(22): see declaration of "boost::noncopyable_::noncopyable" [...]\boost\thread\mutex.hpp(33): see declaration of "boost::mutex"

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date serialization fails with non-standard locales
by Paolo Coletta 28 May '05

28 May '05

I'm not sure if this is a bug or if I'm misusing the library. It seems that serializing boost::posix_time_ptime fails when using non-standard locale (Windows Xp OS - vc 7.1 compiler - boost updated from CVS few days ago). As an example, try adding std::locale::global( std::locale( "en" ) ); as the first line of the testtime_serialize.cpp; this causes the test to fail when doing ia >> pt2; I tried to understand what was happening, and it seems to me that the problem is in keeping into account locale when serializing, while ignoring it while unserializing. In greg_serialize.hpp to_iso_string(d) may generate something like "2,0050527"; the method from_undelimited_string(ds) used to load the serialized date, expects a 4,2,2 format. Paolo

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Re: [Boost-users] Re: building and installing boost
by TBoafo＠aol.com 28 May '05

28 May '05

Hi Dave, 1. I dont have BOOST_ROOT defined in my environment. 2. I still get messages with loading jam files when I try C:\temp\boost_1_32_0>bjam -sBOOST_ROOT=."-sTOOLS=vc-7_1" install --------------------------------------------------------------------- skipping Boost.Python library build due to missing or incorrect configuration couldn't find Python.h in "c:/tools/python/include" You can configure the location of your python installation by setting: PYTHON_ROOT - currently "c:/tools/python" PYTHON_VERSION - The 2-part python Major.Minor version number (e.g. "2.2", NOT "2.2.1") - currently "2.2" The following are automatically configured from PYTHON_ROOT if not otherwise set: PYTHON_LIB_PATH - path to Python library object; currently "c:/tools/python/libs" --------------------------------------------------------------------- Jamfile:247: in load-jamfiles *** argument error * rule stage ( name : sources + : requirements * : local-build * ) * called with: ( include/boost-1_32 : : <locate>C:\Boost <tree-subdirs>C:\temp\ boost_1_32_0 <target>install : ) * missing argument sources C:\temp\boost_1_32_0\tools/build/v1\boost-base.jam:2306:see definition of rule ' stage' being called C:\temp\boost_1_32_0\tools\build\v1\bootstrap.jam:21: in boost-build C:\temp\boost_1_32_0\boost-build.jam:16: in module scope 3. I can't see any files as per your instructions in c:\boost. cd boost DIR compatibility\cpp_c_headers\c* DIR *.hpp *.ipp *.h *.inc 4. If I try to download a fresh boost download which version should I download for this to work with vc 7.1? Regards Theo

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