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

mathematical interval limits
by Tim Blechmann 16 Apr '08

16 Apr '08

hi all, is there a c++/boost.math way to find the highest representable floating point number lower than a certain limit ... something like boost::supremum<float>(1.f)? thanks, tim -- tim(a)klingt.org http://tim.klingt.org Avoid the world, it's just a lot of dust and drag and means nothing in the end. Jack Kerouac

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empty a thread_group
by Axel 16 Apr '08

16 Apr '08

Hello I m using a boost::thread_group instance to handle a limited number of threads. When the thread_group reach a defined size, I cal join_all() on it and I wonder how I could clear it without having to keep a pointer to its threads and call remove_thread() for each one. I thought about destruct th thread_group instance but I m not sure it's a good idea, so any advice is welcome. Regards Axel

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boost.function and phoenix.bind
by Sergei Politov 15 Apr '08

15 Apr '08

The following example: ============================================== #include <boost/function.hpp> #include <boost/spirit/phoenix.hpp> int main() { boost::function<void()> f; phoenix::bind(f); } ============================================== Produces compilation warning on MSVC 9.0: C:\work\cpp\bind.cpp : warning C4717: 'phoenix::functor_action<boost::function<void __cdecl(void),std::allocator<void> > >::functor_action<boost::function<void __cdecl(void),std::allocator<void> > >' : recursive on all control paths, function will cause runtime stack overflow And stack overflow in runtime. What is wrong in this example?

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boost interprocess: managed_shared_memory overhead
by hgdhfdghsa＠Safe-mail.net 15 Apr '08

15 Apr '08

Hello again, I have one managed_shared_memory, which contains exactly one instance of a certain structure, allocated via MySegment.find_or_construct<TheClass>(interprocess::unique_instance)(...); How can I determine how big the segment must be? interprocess::managed_shared_memory ConfigurationManagerSegment(interprocess::open_or_create, "sharedMem", sizeof(TheClass)+x); //What should be x? Thank you

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Re: [Boost-users] libboost_filesystem compile error in qnx
by Ricardo Perrone 15 Apr '08

15 Apr '08

Hi Guenther Thanks for help me, the compilation was a successfuly. Now, the libraries (regex, filesystem) are installed best regards Ricardo > Date: Fri, 11 Apr 2008 07:29:50 +0000 (UTC) > From: Guenther Stattenberger > Subject: Re: [Boost-users] libboost_filesystem compile error in qnx > To: boost-users(a)lists.boost.org > Message-ID: > Content-Type: text/plain; charset=us-ascii > > Hi, > > according to the QNX documentation, strerror itself is thread-safe, > therefore I thought it correct to add the QNX switch to > libs\system\src\error_code.cpp:86 > > # if defined(BOOST_WINDOWS_API) || defined(__hpux) || defined(__sun)\ > || (defined(__linux) && (!defined(__USE_XOPEN2K) || > defined(BOOST_SYSTEM_USE_STRERROR)))\ > || (defined(__osf__) && !defined(_REENTRANT))\ > || (defined(__vms))\ > || (defined(__QNXNTO__)) // <=================================== > > Any comments on that? > > In addition, I had to uncomment the case statement for EALREADY later in this > file. Since the QNX errno.h header defines > #define EALREADY EBUSY > it won't compile otherwise. > > Hope that helps. > > best regards > Guenther ____________________________________________________________________________________ Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ

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string boost::split
by Dmitry Teslenko 15 Apr '08

15 Apr '08

Hello! For example I want to split string with single char '\t' delimeter. According to docs this can be done this way: std::vector<std::string> options; std::string sep; sep += '\t'; boost::split(options, line, boost::is_any_of(sep)); But if I want to use double tab as a delimiter? Is there an alternative to boost::is_any_of like "boost::just_what_i_say"

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[serialization] Is anybody else having problems building serialization?
by John Femiani 15 Apr '08

15 Apr '08

Hi, I am having problems building the serialization library with svn HEAD. I checked out the boost trunk into C:/JOHN/hvm/src/boost, and recently I began seeing this when I build boost with vc8.0: C:\JOHN\hvm\src\boost>..\..\bin\bjam --build-type=complete --stagedir=..\..\ threading=multi link=static --toolset=msvc --with-serialization stage libs\config\test\Jamfile.v2:41: in modules.load rule compile-fail unknown in module Jamfile</C:/JOHN/hvm/src/boost/libs/config/test>. C:/JOHN/hvm/src/boost/tools/build/v2/build\project.jam:307: in load-jamfile C:/JOHN/hvm/src/boost/tools/build/v2/build\project.jam:63: in load C:/JOHN/hvm/src/boost/tools/build/v2/build\project.jam:116: in load-parent C:/JOHN/hvm/src/boost/tools/build/v2/build\project.jam:443: in initialize C:/JOHN/hvm/src/boost/tools/build/v2/build\project.jam:297: in load-jamfile C:/JOHN/hvm/src/boost/tools/build/v2/build\project.jam:63: in load C:/JOHN/hvm/src/boost/tools/build/v2/build\project.jam:167: in project.find C:/JOHN/hvm/src/boost/tools/build/v2/build\targets.jam:354: in find-really C:/JOHN/hvm/src/boost/tools/build/v2/build\targets.jam:408: in object(project-target)(a)79.find C:/JOHN/hvm/src/boost/tools/build/v2/build\targets.jam:827: in resolve-reference C:/JOHN/hvm/src/boost/tools/build/v2/build\targets.jam:843: in targets.generate-from-reference C:/JOHN/hvm/src/boost/tools/build/v2/build\targets.jam:1129: in generate-dependencies C:/JOHN/hvm/src/boost/tools/build/v2/build\targets.jam:1176: in object(typed-target)(a)84.generate C:/JOHN/hvm/src/boost/tools/build/v2/build\targets.jam:742: in generate-really C:/JOHN/hvm/src/boost/tools/build/v2/build\targets.jam:715: in object(main-target)(a)150.generate C:/JOHN/hvm/src/boost/tools/build/v2/build\targets.jam:254: in object(project-target)(a)79.generate C:/JOHN/hvm/src/boost/tools/build/v2/build\targets.jam:858: in targets.generate-from-reference C:/JOHN/hvm/src/boost/tools/build/v2/build\targets.jam:1129: in generate-dependencies C:/JOHN/hvm/src/boost/tools/build/v2/build\targets.jam:1179: in object(install-target-class)(a)70.generate C:/JOHN/hvm/src/boost/tools/build/v2/build\targets.jam:742: in generate-really C:/JOHN/hvm/src/boost/tools/build/v2/build\targets.jam:715: in object(main-target)(a)129.generate C:/JOHN/hvm/src/boost/tools/build/v2/build\targets.jam:858: in targets.generate-from-reference C:/JOHN/hvm/src/boost/tools/build/v2/build\targets.jam:1129: in generate-dependencies C:/JOHN/hvm/src/boost/tools/build/v2/build\targets.jam:1179: in object(alias-target-class)(a)76.generate C:/JOHN/hvm/src/boost/tools/build/v2/build\targets.jam:742: in generate-really C:/JOHN/hvm/src/boost/tools/build/v2/build\targets.jam:715: in object(main-target)(a)133.generate C:/JOHN/hvm/src/boost/tools/build/v2\build-system.jam:663: in load C:\JOHN\hvm\src\boost\tools\build\v2/kernel\modules.jam:267: in import C:\JOHN\hvm\src\boost\tools\build\v2/kernel/bootstrap.jam:134: in boost-build C:\JOHN\hvm\src\boost\boost-build.jam:11: in module scope It looks like an issue crept into the jam file recently because it _used_ to work. Any help here would be great! Thanks, John

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boost::serialization - trying to serialize derived class and base class.
by j.c. 15 Apr '08

15 Apr '08

I am writing a packet base class that can be serialized. The class so far looks like: class packet_base { using namespace boost; public: packet_base(); ~packet_base(); friend class boost::serialization::access; template <typename Archive> void serialize(Archive & ar, const unsigned int version) { ar & m_length; ar & m_type; ar & m_method; } private: uint16_t m_length; uint16_t m_type; uint16_t m_method; }; The question now is how can I derive class A from packet_base and have both packet_base and A's variables serialized? Obviously base_class needs to be archived first so it's variables are at the front of the buffer. Thanks in advance. J

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Problem building serialization with gcc mingw 3.4.5
by Markus Svilans 14 Apr '08

14 Apr '08

Dear mailing list, I am having some trouble building Boost 1.35.0, using gcc mingw 3.4.5. When building the serialization library, I get the following error message on many of the files: "wide char i/o not supported on this platform" The bjam command line I used is: bjam --build-dir="C:\boost_1_35_0\built" --toolset=gcc --with-serialization I've looked through some of the Boost configuration header files, and it seems that the BOOST_NO_STD_WSTREAMBUF value is not being #defined. (I was under the impression that gcc mingw 3.4.5 supports wide character i/o, is this correct?) Has anyone else had this problem, and is there a solution to getting serialization to build properly using my gcc compiler? Thanks very much, Markus.

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boost.exception errors
by Olaf Peter 14 Apr '08

14 Apr '08

Hi, I've used the boost.exception from svn (Revision 44352) and got the compile errors: $ LANG=en g++ -I ../../3rd_party/boost-svn/ -Wall eh.cpp -o eh && ./eh ../../3rd_party/boost-svn/boost/exception/info.hpp: In function 'boost::shared_ptr<const typename ErrorInfo::value_type> boost::get_error_info(const E&) [with ErrorInfo = boost::error_info<boost::tag_throw_function, const char*>, E = boost::exception]': eh.cpp:21: instantiated from here ../../boost-svn/boost/exception/info.hpp:104: error: no matching function for call to 'boost::shared_ptr<const char* const>::shared_ptr(boost::shared_ptr<const boost::exception_detail::error_info_base>&, const char* const*)' /usr/include/boost/shared_ptr.hpp:144: note: candidates are: boost::shared_ptr<T>::shared_ptr() [with T = const char* const] /usr/include/boost/shared_ptr.hpp:131: note: boost::shared_ptr<const char* const>::shared_ptr(const boost::shared_ptr<const char* const>&) from this file: #include <boost/exception/exception.hpp> #include <boost/exception/info_tuple.hpp> #include <boost/exception/info.hpp> #include <exception> #include <boost/shared_ptr.hpp> #include <iostream> struct test_exception : boost::exception {}; int main() { try { throw test_exception() << BOOST_ERROR_INFO ; } catch( const boost::exception& e ) { using namespace boost; std::cerr << "Caught exception:\n" << e.what() << "\n"; shared_ptr<const char * const> function = get_error_info<throw_function>( e ); // shared_ptr<const char * const> file = get_error_info<throw_file>( e ); // shared_ptr<int* const> line = get_error_info<throw_line>( e ); // std::cerr << " in " << file << "(" << line << "): " << function << std::endl; } } BTW, the example_io.cpp doesn't compile too. Do I have to use the complete svn trunk? Thanks, Olaf

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