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[serialization]-- serialize a std::vector<>?
by Rich Peters 15 Oct '07

15 Oct '07

Hello, sorry for the newbie questions... I have some sample serialization code where I serialize a container. if that container is std::list<sometype> it works fine. the same code with a std::vector<sometype> fails to compile. are vectors supported for serialization? I cant find any specific mention in the documentation or via searching. thanks

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[ptr_map]const_iterator does not represent value_type
by Bill Buklis 15 Oct '07

15 Oct '07

In ptr_map, const_iterator does not represent value_type. Given this map: typedef boost::ptr_map<DWORD, int> BOOSTMAP; BOOSTMAP::value_type equates to: boost::ptr_container_detail::ref_pair<DWORD, int* const> BOOSTMAP::iterator does return this, but const_iterator returns: boost::ptr_container_detail::ref_pair<DWORD, const int* const> which is unlike std::map which represents const value_type for const_iterator. Since this is a different structure, it's incompatible with BOOSTMAP::value_type. The following code works using std::map: typedef std::map<DWORD, int*> STDMAP; int sample = 5; STDMAP sm; sm.insert( STDMAP::value_type(10,&sample) ); STDMAP::iterator sfirst = sm.begin(); STDMAP::const_iterator scfirst = sm.begin(); STDMAP::value_type& svt = *sfirst; const STDMAP::value_type& scvt = *scfirst; But, the same fails on the last line with boost::ptr_map typedef boost::ptr_map<DWORD, int> BOOSTMAP; BOOSTMAP bm; DWORD key = 10; bm.insert( key, new int(5) ); BOOSTMAP::iterator bfirst = bm.begin(); BOOSTMAP::const_iterator bcfirst = bm.begin(); BOOSTMAP::value_type& bvt = *bfirst; const BOOSTMAP::value_type& bcvt = *bcfirst; Also, it is not possible to bind to one of the members BOOSTMAP::value_type. For example, this works with std::map, but fails with ptr_map: boost::bind( &BOOSTMAP::value_type::first, _1 ); -- Bill --

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[tools/regression] Directory reorganization
by Beman Dawes 15 Oct '07

15 Oct '07

There's some reorganization in progress in the trunk/tools/regression directory. This shouldn't affect most developers or users, since any of our Boost scripts that depend on these directory locations are being updated too. But if you've got any of your own scripts, make files, or IDE projects that depend on these directory locations, you will need to update them accordingly. Thanks to Rene Rivera for cleaning up this aspect of our tools directory structure! --Beman

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Build Problem: bjam + boost + python
by Michael Bradley Jr 15 Oct '07

15 Oct '07

Hi, I've done a svn check_out of the boost repository. I'm trying to build it with the underlaying options, but can't achieve that goal due to the underlaying error messages. Any help or hints will be appreciated Cheers Michael ps A couple of weeks ago, i was able to compile boost with the same options without a problem. "bin/bjam.exe" -d 0 stage --stagedir=. --toolset=msvc link=sta tic runtime-link=shared architecture=x86 release debug address-model=32 warning: Graph library does not contain optional GraphML reader. note: to enable GraphML support, set EXPAT_INCLUDE and EXPAT_LIBPATH to the note: directories containing the Expat headers and libraries, respectively. warning: skipping optional Message Passing Interface (MPI) library. note: to enable MPI support, add "using mpi ;" to user-config.jam. note: to suppress this message, pass "--without-mpi" to bjam. note: otherwise, you can safely ignore this message. Building Boost.Regex with the optional Unicode/ICU support disabled. Please refer to the Boost.Regex documentation for more information (don't panic: this is a strictly optional feature). error: Unable to find file or target named error: '/python//python_for_extensions' error: referred from project at error: 'libs/python/build'

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[boost-users][system] Mixing non-errors and errors (status_code vs. error_code)
by Darren Garvey 15 Oct '07

15 Oct '07

Hello, I've been wondering for a while if it's sensible to use Boost.System for transporting status_codes, rather than strictly error_codes. I'm aware than I *may* be trying to misuse the system library here, so I'll get straight to an example: If I had an HTTP library that retrieved remote pages, I might want to use, as (a very crude) example: template<typename MutableBufferSequence> void get_page(http::connection& conn, MutableBufferSequence& buf) { boost::system::error_code ec; conn.get_page(buf, ec); if (ec) throw ec; } The problem with relying on error_code to carry the errors is that the various success codes (eg. 200 OK, 201 ACCEPTED, 202 CREATED, etc.) seem to get lost, unless you class them as errors. Then you'd need something like: - if (ec) throw ec; + if (ec >= http::ok || ec <= http::multi_status) throw ec; It's not a massive pain, but having `ec == true` even when you don't have an error isn't helpful. AFAICT, any non-zero error value is an error that'll give `ec == true`. I feel like I'm missing something here, please tell me if I am. Regards, Darren PS. I'm trying to avoid having to make something that lies on top of boost::system::error_code, like a status_code class.

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[Serialization] Example for Boost.Any
by Joseph Lisee 15 Oct '07

15 Oct '07

Hello, 2 years ago on this list there was a discussion on how to serialize/deserialize a Boost.Any variable. I read through and found some proposals, but never any implementations. I was wondering whether anyone had ever gotten around to implementing it? I have no qualms about using a custom Boost.Any with serialization support coded in. -Joe

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what::runtime_error::std already defined
by Lars Schouw 15 Oct '07

15 Oct '07

I am getting these linking errors and can't figure out where it comes from. 4>libboost_regex-vc80-mt-gd-1_34_1.lib(instances.obj) : error LNK2005: "public: virtual char const * __thiscall std::runtime_error::what(void)const " (?what@runtime_error@std@@UBEPBDXZ) already defined in Curve.obj I am using Visual Studio 2005 SP1 and Windows XP Lars ____________________________________________________________________________________ Moody friends. Drama queens. Your life? Nope! - their life, your story. Play Sims Stories at Yahoo! Games. http://sims.yahoo.com/

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[program_options] Dynamic linking broken with VS7.1
by Robert Brueckmann 15 Oct '07

15 Oct '07

I tried to compile a simple test program, but it doesn't link dynamically. Any suggestions, what I'm doing wrong? I'm using boost 1.34.1 prebuilt libs from boost-consulting and MSVC 7.1. The test code which fails: #include <boost/program_options.hpp> namespace po = boost::program_options; int main(int argc, char** argv) { unsigned int i1; po::options_description normal_options("parameters"); normal_options.add_options() ("test,t", po::value<unsigned int>(&i1)->default_value(0), "test") ; return 0; } I compile using the following command: cl /TP /EHsc /nologo /GR /WL /W2 /Od /MDd /GS /Z7 /DBOOST_ALL_NO_LIB /Ih:\repos\trunk\3rd\include\common\boost\1_34_1 /c main.cpp /Fomain.obj The linker command link /nologo /OUT:test.exe /LIBPATH:h:\repos\trunk\3rd\lib\win32\cl\13.10\boost\1_34_1 boost_program_options-vc71-mt-gd-1_34_1.lib /DEBUG main.obj fails with the error message main.obj : error LNK2001: unresolved external symbol "class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > boost::program_options::arg" (?arg@program_options@boost@@3V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@A) However, when linking statically using link /nologo /OUT:test.exe /LIBPATH:h:\repos\trunk\3rd\lib\win32\cl\13.10\boost\1_34_1 libboost_program_options-vc71-mt-gd-1_34_1.lib /DEBUG main.obj then everything is working... Any ideas? Thank you in advance, Robert

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[Iostreams] stream not clearing state
by Benjamin Collins 14 Oct '07

14 Oct '07

I'm trying to use a stream and open/close the underlying device on the fly. Here's my test code: #include <iostream> #include <boost/filesystem.hpp> namespace fs = boost::filesystem; #include <boost/iostreams/device/mapped_file.hpp> #include <boost/iostreams/stream.hpp> namespace io = boost::iostreams; namespace { const uint32_t block_size = io::mapped_file_source::alignment(); } bool test1() { io::mapped_file_params mfp("rand.bin"); mfp.mode = std::ios_base::in | std::ios_base::binary; mfp.length = block_size; io::mapped_file mf(mfp); io::stream<io::mapped_file> in(mf); int blocks = fs::file_size("rand.bin")/block_size; if (fs::file_size("rand.bin") % block_size) ++blocks; for (int i=0;i<blocks;++i) { in->close(); mfp.offset = block_size*i; std::cout << "mapping bytes [" << block_size*i << " - " << block_size*(i+1) - 1 << "]\n"; in->open(mfp); in.clear(); std::cout << "stream is in state: [ "; if(in.rdstate() | std::ios::goodbit) std::cout << "good "; if(in.rdstate() | std::ios::badbit) std::cout << "bad "; if(in.rdstate() | std::ios::failbit) std::cout << "fail "; if(in.rdstate() | std::ios::eofbit) std::cout << "eof "; std::cout << "]\n"; int count=0; char x; while(!in.eof()) { if(io::stream<io::mapped_file>::traits_type::eof() == (x = in.get())) throw std::runtime_error("unexpected eof"); std::cout << '.'; ++count; } if(0==count) throw std::runtime_error("unable to read characters in this map"); else std::cout << count << "bytes read.\n"; } } If you don't like to see code in email, see here: http://pastebin.com/m40e9432b This program prints the following: ------------------------------------------------ mapping bytes [0 - 4095] stream is in state: [ bad fail eof ] terminate called after throwing an instance of 'std::runtime_error' what(): unexpected eof Aborted So what gives? Why isn't boost::iostreams::stream clearing its state properly? -- Benjamin A. Collins <ben.collins(a)acm.org> http://bloggoergosum.us

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[BGL] Inverse property mapping?
by "Alejandro M. Aragón" 14 Oct '07

14 Oct '07

Hello everyone, I've been looking for some time at the documentation and I couldn't find a single way to obtain an inverse mapping for a property map. That is, given a property p, I would like to obtain a vertex descriptor v. It seems that the mapping is only in one direction. Is there a way to obtain the inverse mapping too? If so, what is the complexity associated with obtaining the vertex descriptor? Thank you, a²

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