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[Review] Type Traits Extension ending tomorrow
by Joel Falcou 17 Mar '11

17 Mar '11

Dear All, The fast track review of Frédéric Bron's extensions to the Type Traits Library is ending tomorrow. If you plan to submit a review, please do so as soon as possible. Thanks in advance to all participants of the review. =========== What is it? =========== This extension adds 37 new traits corresponding to the following 37 operators: - binary: ==, !=,<,<=,>,>=, , +, -, *, /, %, +=, -=, *=, /=, %=, , &&, ||, ,&, |, ^,<<,>>,&=, |=, ^=,<<=,>>= - prefix: ++, --, +, -, !, ~, * - postfix: ++, -- Each trait can detect if the operator can be used with particular types and if needed, if the return type is convertible to some type. =================== Getting the library =================== The latest version can be downloaded by different ways: - from the vault with unix line ending: http://www.boostpro.com/vault/index.php?action=downloadfile&filename=type_t… - from the vault with dos line ending: http://www.boostpro.com/vault/index.php?action=downloadfile&filename=type_t… - from the sandbox:http://svn.boost.org/svn/boost/sandbox/type_traits/ The entry point of the documentation is type_traits/libs/type_traits/doc/html/boost_typetraits/category/value_traits/operators.html The library has been tested with: - MSVC 8, 9, 10 on Windows, - g++ 4.4.5 on Linux, - intel 10.0 and 11.1 on Linux. To test the library, the simplest is to untar the headers in your boost include directory. For this, you can download the header part of the extension: - from the vault with unix line ending: http://www.boostpro.com/vault/index.php?action=downloadfile&filename=type_t… - from the vault with dos line ending: http://www.boostpro.com/vault/index.php?action=downloadfile&filename=type_t…

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Boost profile for ODB
by Boris Kolpackov 17 Mar '11

17 Mar '11

Hi, I would like to briefly mention that we have released the Boost profile for ODB, an open-source object-relational mapping (ORM) system for C++. The Boost profile provides glue code that seamlessly integrates various Boost components, such as smart pointers, containers, and value types, with ODB. This initial release of the profile covers the most commonly used types from the smart_ptr, unordered, and date_time Boost libraries. For example, now we can easily persist a class like this: #pragma db object class employee { ... boost::gregorian::date born_; boost::unordered_set<std::string> emails_; boost::shared_ptr<employer> employer_; }; For a more detailed discussion of the Boost profile, see the following blog post: http://www.codesynthesis.com/~boris/blog/2011/03/16/odb-1-2-0-released/ Or refer directly to Part III, "Profiles" in the ODB Manual: http://www.codesynthesis.com/products/odb/doc/manual.xhtml#III Boris

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[units] Creating specific unit quantities
by Ryan 17 Mar '11

17 Mar '11

In the Boost Unit documentation there are examples on creating quantities using a dimension. There doesn't seem to be any documentation on using a specific type of dimension as a quantity. Is it possible to create a quantity with a specific type of dimension value? using namespace boost::units; using namespace boost::units::si; quantity<length> L = 2.0*meters; //Is it possible to have meters instead of length as a quantity? quantity<???> L = 2.0 * meters; Ryan

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Library Developers Battling Cyclic Header Dependency
by Ryan 17 Mar '11

17 Mar '11

In the boost library system certain libraries need to be compiled and linked into a project. For example, libraries would need to be compiled to remove cyclic header dependencies. In the boost library system I coundn't find any .cpp files that would indecate a compilable library. So how do library developers create compilable files in the boost libraries? The following two files would need to be broken up and compiled to remove the dependencies, correct? Ryan //File A.hpp class B; class A { double x; public: B convertToB(void) { return B(x); } }; //File B.hpp class A; class B { double y; public: A convertToA(void) { return A(y); } };

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[Serialization] Segfault while serializing derived pointers using multi DLLs
by François Mauger 17 Mar '11

17 Mar '11

Hi all (and particularly Boost/(De-)Serializer), I use Boost 1.44, gcc 4.4.1, Linux. The problem: I have two home made libraries compiled as DLL under linux: - 'datatools' provides the 'libdatatools.so' DLL - 'brio' provides the 'libbrio.so' DLL I use Boost serialization features for derived pointers. Below are the details: STEP 1: 'datatools' is the base library. It defines: - its own namespace: 'datatools' - a virtual class (interface) named 'i_serializable' from which all other serializable classes should inherit in order to benefit of the (de)serialization mechanism through pointer to this base class. [see http://www.boost.org/doc/libs/1_46_1/libs/serialization/doc/serialization.h…] - some concrete classes (A, B, C) that inherit from the 'i_serializable' interface and register themselves using the export key features described in http://www.boost.org/doc/libs/1_46_1/libs/serialization/doc/special.html#ex… Typical inheritance diagram looks like: <pre> datatools::i_serializable | +--------------+--------------+ | | | datatools::A datatools::B datatools::C | datatools::A' </pre> Here is the typical model of the 'A.hpp' header file for the A class: <pre> ... #include <datatools/serialization/archives_list.hpp> // include Boost/Serialization text/XML/binary archives #include <datatools/serialization/i_serializable.hpp> // include the abstract mother interface class ... namespace datatools { class A: public i_serializable { blah-blah.. // no inline code (from http://www.boost.org/doc/libs/1_46_1/libs/serialization/doc/special.html#dl…) template<class Archive> void serialize (Archive & ar, const unsigned int version); }; } // register the class with a specific GUID: BOOST_CLASS_EXPORT_KEY2 (datatools::A, "datatools::A"); </pre> Here is the model of the 'A.cpp' implementation file: <pre> namespace datatools { ... template<class Archive> void A::serialize (Archive & ar, const unsigned int version) { ar & boost::serialization::make_nvp( "datatools__serialization__i_serializable", boost::serialization::base_object<datatools::serialization::i_serializable >(*this) ); ar & more data (with NVP stuff)...; } } // end of namespace datatools BOOST_CLASS_EXPORT_IMPLEMENT(datatools::A) // explicit instantiation for all kind of known archives: #include <datatools/serialization/archives_list.hpp> // include the known text/XML/binary archives template void datatools::A::serialize(boost::archive::text_oarchive & ar, const unsigned int version); template void datatools::A::serialize(boost::archive::text_iarchive & ar, const unsigned int version); template void datatools::A::serialize(boost::archive::xml_oarchive & ar, const unsigned int version); ... more... </pre> Finaly, I can compile all this stuff using gcc and build the 'libdatatools.so' library which I prepend to my LD_LIBRARY_PATH. Everything looks fine. A test program 'prg1.cpp' that links against only 'libdatatools.so' and 'libboost_serialization.so' works prefectly, serialiazing and deserialiazing any collection of pointers to A,B, or C classes without problem. A must ! Thanks to Robert for that magic ! At this point, everything looks (is?) fine. Note that I have followed (in principle) all the guidelines provided by Robert. STEP 2: Now let's consider the actual problem ! As said before, my 'datatools' library is the base of some modular project with some other libraries that depend on 'datatools' (and Boost/Serialization). The 'brio' library is such a beast: <pre> Boost/Serialization | datatools | brio </pre> It has its own namespace: 'brio' It provides a few other dedicated classes, inherited from the 'datatools::i_serializable' abstract class and which are serializable via Boost. Let's consider the serializable 'brio::D' class, designed on the model of 'datatools::A' and using the same implementation recommendations. I have followed the guidelines use for the 'datatools::A' class to write both 'D.hpp' and 'D.cpp' files. Now the inheritance scheme is: <pre> datatools::i_serializable : | : +--------------+--------------+------------+-----+- - - - | | | : | datatools::A datatools::B datatools::C : brio::D | : datatools::A' : libdatatools.so scope : libbrio.so scope : </pre> I can compile the 'libbrio.so' DLL without any problem. Now I want to run a sample program 'prg2.cpp' that performs some (de)serialization operations on a collection of pointers to 'datatools::A', 'datatools::B', 'datatools::C' AND 'brio::D' instances. This program is linked against the following libraries (among others): - libbrio.so - libdatatools.so - libboost_serialization.so Well, it compiles perfectly. Note this program links against third-party libraries too, among them some are explicitely using 'dlopen' and 'dlclose' to satisfy internal and critical features that are out of my scope. I have no idea if this can have side-effect. However, when I run it, I observed the following behaviour: - all (de)serialization operations are done properly and I get files with embeded (text/XML...) portable archives than can be reloaded without problem. - at the END of the program, while some cleaning code is invoked (some kind of deep buried code out of my skills and understanding), I get a Segmentation fault. Here is a dump of the GDB backtrace: <pre> Program received signal SIGSEGV, Segmentation fault. 0x02647c78 in boost::serialization::typeid_system::extended_type_info_typeid_0::is_less_than(boost::serialization::extended_type_info const&) const () from /scratch/sw/boost/install-1_44_0-Linux-i686-gcc44/lib/libboost_serialization.so.1.44.0 (gdb) bt #0 0x02647c78 in boost::serialization::typeid_system::extended_type_info_typeid_0::is_less_than(boost::serialization::extended_type_info const&) const () from /scratch/sw/boost/install-1_44_0-Linux-i686-gcc44/lib/libboost_serialization.so.1.44.0 #1 0x0264737b in boost::serialization::extended_type_info::operator<(boost::serialization::extended_type_info const&) const () from /scratch/sw/boost/install-1_44_0-Linux-i686-gcc44/lib/libboost_serialization.so.1.44.0 #2 0x0264dcac in boost::serialization::void_cast_detail::void_caster::operator<(boost::serialization::void_cast_detail::void_caster const&) const () from /scratch/sw/boost/install-1_44_0-Linux-i686-gcc44/lib/libboost_serialization.so.1.44.0 #3 0x0264e56d in boost::serialization::void_cast_detail::void_caster::recursive_unregister() const () from /scratch/sw/boost/install-1_44_0-Linux-i686-gcc44/lib/libboost_serialization.so.1.44.0 #4 0x0264ed8d in boost::serialization::void_cast_detail::void_caster_shortcut::~void_caster_shortcut() () from /scratch/sw/boost/install-1_44_0-Linux-i686-gcc44/lib/libboost_serialization.so.1.44.0 #5 0x0264e5ee in boost::serialization::void_cast_detail::void_caster::recursive_unregister() const () from /scratch/sw/boost/install-1_44_0-Linux-i686-gcc44/lib/libboost_serialization.so.1.44.0 #6 0x024a6da7 in boost::serialization::void_cast_detail::void_caster_primitive<datatools::test::more_data_t, datatools::test::data_t>::~void_caster_primitive() () from /home/mauger/Private/Work/lpc_nemo_svn/sw/datatools/datatools_trunk/Linux-i686/lib/libdatatools.so #7 0x024a6f04 in boost::serialization::detail::singleton_wrapper<boost::serialization::void_cast_detail::void_caster_primitive<datatools::test::more_data_t, datatools::test::data_t> >::~singleton_wrapper() () from /home/mauger/Private/Work/lpc_nemo_svn/sw/datatools/datatools_trunk/Linux-i686/lib/libdatatools.so #8 0x0298c428 in __cxa_finalize (d=0x2609830) at cxa_finalize.c:56 #9 0x02426f04 in __do_global_dtors_aux () from /home/mauger/Private/Work/lpc_nemo_svn/sw/datatools/datatools_trunk/Linux-i686/lib/libdatatools.so #10 0x02534100 in _fini () from /home/mauger/Private/Work/lpc_nemo_svn/sw/datatools/datatools_trunk/Linux-i686/lib/libdatatools.so #11 0x0011dee6 in _dl_fini () at dl-fini.c:248 #12 0x0298c05f in __run_exit_handlers (status=0, listp=0x2a9e304, run_list_atexit=true) at exit.c:78 #13 0x0298c0cf in *__GI_exit (status=0) at exit.c:100 #14 0x02973b5e in __libc_start_main (main=0x8059495 <main>, argc=1, ubp_av=0xbfffcfd4, init=0x8061c40 <__libc_csu_init>, fini=0x8061c30 <__libc_csu_fini>, rtld_fini=0x11dcc0 <_dl_fini>, stack_end=0xbfffcfcc) at libc-start.c:252 #15 0x080592c1 in _start () at ../sysdeps/i386/elf/start.S:119 </pre> If one ignores the nasty details from this stack (local pathes and names), one observe that the problem seems to be related to some unregistration of some Boost/Serialization material. It occurs while the executable is trying to destruct some singleton_wrapper template class that manages some serializable classes from the 'datatools' library: - class 'datatools::test::more_data_t' (call it A') - and its mother class 'datatools::test::data_t', (call it A) inherited from 'datatools::i_serializable'. I expect such singleton is a static instance attached in some DLL. Am I wrong ? If not, which DLL is concerned 'libdatatools.so', 'libbrio.so' ? My feeling is that I have a problem with some arbitrary order of library unloading and messy unregistration that comes with. Unless there is a specific order to aggregate module within in DLL (A.o B.o A'.o...). Unfortunately, my skills are too limited to make a better idea and find a solution. There is some comments by Robert concerning such possible problems, but I'm not sure it makes sense in my case. So I will really appreciate if someone could advise me and possibly give me some hints. Thanks a lot for attention and help. Apologize for this rather long and technical issue. Regards frc -- François Mauger Groupe "Interactions Fondamentales et Nature du Neutrino" NEMO-3/SuperNEMO Collaboration LPC Caen-CNRS/IN2P3-UCBN-ENSICAEN Département de Physique -- Université de Caen Basse-Normandie Adresse/address: Laboratoire de Physique Corpusculaire de Caen (UMR 6534) ENSICAEN 6, Boulevard du Marechal Juin 14050 CAEN Cedex FRANCE Courriel/e-mail: mauger(a)lpccaen.in2p3.fr Tél./phone: 02 31 45 25 12 / (+33) 2 31 45 25 12 Fax: 02 31 45 25 49 / (+33) 2 31 45 25 49

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[lexical_cast] crash using Intel 12.0 with optimizations enabled
by Thomas Mang 17 Mar '11

17 Mar '11

Hi, I tracked down a crash to a call to boost::lexical_cast (Boost 1.46.1( when using the Intel 12.0 compiler for Windows (embedded into MSVC8) if optimizations are enabled. I would have expected the mini-program below to work smoothly, but instead the second catch-handler is entered (unknown exception). The offending compiler option is /O; in all cases except of /Od [all optimizations disabled] the exception is raised. May I strongly suppose this is either a boost or an Intel compiler issue, or did I misunderstand something ? Below are full command-line compiler options and teh program. Thanks and best, Thomas command line options: /c /O2 /Og /Qipo /I "C:\Libraries\Boost\boost_1_46_1" /D "WIN32" /D "NDEBUG" /D "_CONSOLE" /D "_UNICODE" /D "UNICODE" /EHsc /MD /GS- /fp:strict /Za /Fo"ReleaseFinal/" /W3 /nologo /Wp64 /Zi /Qfp-speculation:strict /Quse-intel-optimized-headers /Qintel-extensions- mini-program: #include <iostream> #include <ostream> #include <string> #include "boost/lexical_cast.hpp" int main() { try { std::string X = boost::lexical_cast<std::string>(2 - 1); std::cout << X << std::endl; } catch (boost::bad_lexical_cast const &) { std::cout << "boost::lexical_cast exception occurred."; } catch (...) { std::cout << "An unknown exception occurred."; } }

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Compiling Boost with 4 byte packing...
by Brian Nantz 17 Mar '11

17 Mar '11

I am trying to get boost asio to work with my code (which is using 4 byte struct member alignment and _cdecl calling convention). I get the following error when calling asio::async_write: Run-Time Check Failure #0 - The value of ESP was not properly saved across a function call. This is usually a result of calling a function declared with one calling convention with a function pointer declared with a different calling convention. What am I missing? I have read everything on ABI that I can find: http://www.boost.org/development/separate_compilation.html I changed boost\config\abi\msvc_prefix.hpp to use #pragma pack(push,4). I also am using the command line option for bjam: cxxflags="/Zp4 /Gd" The Microsoft documentation seems to indicate that the /Zp should override the #pragma if the #pragma is larger or equal: http://msdn.microsoft.com/en-us/library/ms253935.aspx http://msdn.microsoft.com/en-us/library/46t77ak2.aspx Any help would be greatly appreciated, Brian

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[boost-user][asio]How can i limit tcpserver's connection count?
by rhapsodyn 16 Mar '11

16 Mar '11

here‘s the code server： class tcp_server { public: tcp_server(boost::asio::io_service& io_service) : acceptor_(io_service),limit(0) { tcp::endpoint endpoint(tcp::v4(), 10000); acceptor_.open(endpoint.protocol()); acceptor_.bind(endpoint); acceptor_.listen(1); start_accept(); } private: void start_accept() { while(1) { if(limit < 1) break; } tcp::socket* socket = new tcp::socket(acceptor_.io_service()); acceptor_.async_accept(*socket, boost::bind( &tcp_server::handle_accept, this, socket, boost::asio::placeholders::error)); } void handle_accept(tcp::socket* s, const boost::system::error_code& error) { if (!error) { ++limit; start_accept(); } } tcp::acceptor acceptor_; int limit; }; client： int main(int argc, char* argv[]) { int i = 0; try { boost::asio::io_service io_service; tcp::resolver resolver(io_service); tcp::resolver::query query("127.0.0.1", "10000"); tcp::resolver::iterator endpoint_iterator = resolver.resolve(query); tcp::endpoint endpoint = *endpoint_iterator; tcp::socket socket(io_service); socket.connect(endpoint); while(1) {} } catch (std::exception& e) { std::cerr << e.what() << std::endl; } return 0; } I thought i can only launch 1 client, but fact is: i can start two clients and the 3rd one just cerr the what(), what happend there? Is there some better way to get & limit the "living-connection" of the server? -- View this message in context: http://boost.2283326.n4.nabble.com/boost-user-asio-How-can-i-limit-tcpserve… Sent from the Boost - Users mailing list archive at Nabble.com.

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boost::asio::write(), big data-chunks, socket-error 10053
by Sebastian Rudek 15 Mar '11

15 Mar '11

Hello I am having trouble with Sockets under Windows and Linux. When attempting to send much data through boost::asio::write(), the socket error 10053 - connection aborted - occurs. I am sending from a Windows machine over the local network to a server (not using boost), running on linux. This server uses a select to determine whether there is something to read or not. Sending not lots of data, for example 500 bytes, does not fail. But sending some hundred of kilobytes or even megabytes, fails. Does a timeout occur? why? and how can i make my client to transfer all of its data? did you experience something similar? Thanks in advance, regards Sebastian -- Sebastian Rudek, Softwareentwickler Lyncker& Theis GmbH Wilhelmstr. 16 65185 Wiesbaden Germany Fon +49 611/9006951 Fax +49 611/9406125 Handelsregister: HRB 23156 Amtsgericht Wiesbaden Steuernummer: 4323897052 USt-IdNr.: DE255806399 Geschäftsführer: Filip Lyncker, Armin Theis, Patrick Schmidt

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boost::bind can't bind bind_t type right?
by ???? 15 Mar '11

15 Mar '11

#include <iostream> #include <boost/bind.hpp> #include <boost/function.hpp> class test1 { public: template<typename S> double handle(S s) { s(1); std::cout<<"test1\n"; return 1; } template<typename F> void handle1(F f){ boost::bind(&test1::handle<F>,this,f)(); } }; class test2 { public: double handle(int i) { std::cout<<"test2\n"; return i; } }; int _tmain(int argc, _TCHAR* argv[]) { test2 t2; test1 t1; t1.handle1(boost::bind(&test2::handle,t2,_1)); return 0; } in test1::handle1 complie fail on vs2010 and gcc 4.4.1 vs 2010 error:error C2664: "R boost::_mfi::mf1<R,T,A1>::operator ()<test1>(const U &,A1) const": can't convert "double"to "boost::_bi::bind_t<R,F,L>" . but boost::bind(&test1::handle<F>,this,f)(); f is not double,f is bind_t and double only return_type. by the way,boost::bind(&test1::handle<F>,this,boost::ref(f))(); can work.

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