March 2011 - Boost-users - lists.preview.boost.org

boost::python::return_value_policy<bp::reference_existing_object>() is weakref in python?
by Thomas Rab 23 Mar '11

23 Mar '11

I've used boost::python in the past, but this problem has me stumped. Here's part of the class I'm having issues with: class Entity { public: Entity(); ~Entity(); //Call to check our collider against all entities that have "tag" Collider* Collide(const std::string &tag); }; and here is the boost::python code: bp::class_< Entity_wrapper >( "Entity", bp::init< >() ) .def( "Collide" , (::Monocle::Collider * ( ::Monocle::Entity::* )( ::std::string const & ) )( &::Monocle::Entity::Collide ) , ( bp::arg("tag") ), bp::return_value_policy<bp::reference_existing_object>() ) In python if I do something like this: collider = entity.Collision("Paddle") collider is a weakref to 'type' Not a Collider. My other functions that return pointers seem to be fine. Is it just the call policy I'm using? What Collide does is call a static function ("Collide") of the Collision class, which in turn returns a Collider* on success and NULL otherwise. Any help would be appreciated! If you need anymore information, let me know! -- Tom Rab

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[boost::thread] lib broken in trunk for Win32
by teajay 22 Mar '11

22 Mar '11

Hello, I just noticed that the thread lib build for win32 is broken due to a superfluous #if on line 14 in the file tss_pe.cpp. Regards, Thomas Bernard

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[context review] Review - alternative version available
by Oliver Kowalke 22 Mar '11

22 Mar '11

Hi, I've uploaded an alternative version to boost vault (boost.context-alternative_version.zip : http://tinyurl.com/6fpnkro). The documentation is available at http://ok73.ok.funpic.de/alternative/boost/libs/context/doc/html/. changes: - fixed bug for x86_64/sysv/elf assembler file: missing assembler directive .type added - as suggested by Artyom and Vicente: - assembler implementation and native implementation of context switching functions compiled and applied as template arg to context<> -> context<> == context< protected_stack, asm_impl > on UNIX, context< protected_stack, native_impl > on Windows - for Windows assembler implementation is disabled Oliver

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[StateChart] How to pass arguments to a state constructor when doing state transition?
by Zhu Bicen 22 Mar '11

22 Mar '11

Hi all, I have a state like this, which has two parameters in it's constructor except the ctx. I want to know how to pass these two arguments to the constructor, when do state transition? I have tried this: transit< RepeatedPlayingState , 1, 2>(); But it cause compiling error? How to do this? I want to pass something to a new entered state. Thanks! class RepeatedPlayingState: public state< RepeatedPlayingState, PlayingState > { public: RepeatedPlayingState( my_context ctx , long start_pos, long end_pos) : my_base( ctx ){ context< PlayerFsm >().player_.PlayFromTo(start_pos, end_pos); } }; Best Regards Hill

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Re: [Boost-users] compilation error, please help
by Steven Watanabe 22 Mar '11

22 Mar '11

AMDG On 03/22/2011 09:59 AM, kovari andris wrote: > I have version 4.4.5 > I think the latest That wasn't what I was asking. g++ -v gives all the information about how the compiler was configured. In Christ, Steven Watanabe

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Re: [Boost-users] compilation error, please help
by Steven Watanabe 22 Mar '11

22 Mar '11

AMDG On 03/22/2011 08:42 AM, kovari andris wrote: > to the greater glory of God... > I did try some variations of g++ -pthread... > > but did not work. > I got all sorts of suggestions on different forums, but it gives the same error. All right. What does g++ -v say? In Christ, Steven Watanabe

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compilation error, please help
by kovari andris 22 Mar '11

22 Mar '11

Hi folks, I have: installed eclipse on ubuntu 10.10 installed libbost 1.4 using sinaptic pkg manager started a simple new c++ project, #include <boost/thread.hpp> int main(int argc, char* arg[]){ } I tried to build it, and had the error: Invoking: GCC C++ Compiler g++ -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"main.d" -MT"main.d" -o"main.o" "../main.cpp" In file included from /usr/include/boost/thread/detail/platform.hpp:17, from /usr/include/boost/thread/thread.hpp:12, from /usr/include/boost/thread.hpp:13, from ../main.cpp:8: /usr/include/boost/config/requires_threads.hpp:47: error: #error "Compiler threading support is not turned on. Please set the correct command line options for threading: -pthread (Linux), -pthreads (Solaris) or -mthreads (Mingw32)" In file included from /usr/include/boost/thread/thread.hpp:12, from /usr/include/boost/thread.hpp:13, from ../main.cpp:8: /usr/include/boost/thread/detail/platform.hpp:67: error: #error "Sorry, no boost threads are available for this platform." In file included from /usr/include/boost/thread.hpp:13, from ../main.cpp:8: /usr/include/boost/thread/thread.hpp:19: error: #error "Boost threads unavailable on this platform" blablabla...so on... a lot more errors. what am I missing here? I dont understand the error message, and tried to write -pthread wherever I could, but did not work. Any tips? detailed or stepbystep solution please, because I am a beginner, and dont understand chinese:) thank you guys

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newbie fail: Too many levels of symbolic link
by Gary Pajer 22 Mar '11

22 Mar '11

I have a c++ shared library, and I'd like to use the classes and functions in python. So I'm trying boost.python. I'm on Ubuntu 10.10, and I've downloaded the boost tarball. I think I've followed the instructions here<http://www.boost.org/doc/libs/1_46_1/libs/python/doc/building.html>and (more to the point) here<http://www.boost.org/doc/libs/1_46_1/more/getting_started/unix-variants.htm…>to the letter. But when I execute "sudo ./bjam" I get dozens upon dozens of failures. For example, "g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -pthread -DBOOST_ALL_NO_LIB=1 -DBOOST_PYTHON_SOURCE -DBOOST_PYTHON_STATIC_LIB -DNDEBUG -I"." -I"/usr/include/python2.6" -c -o "bin.v2/libs/python/build/gcc-4.4.5/release/link-static/threading-multi/numeric.o" "libs/python/src/numeric.cpp" ...failed gcc.compile.c++ bin.v2/libs/python/build/gcc-4.4.5/release/link-static/threading-multi/numeric.o... gcc.compile.c++ bin.v2/libs/python/build/gcc-4.4.5/release/link-static/threading-multi/list.o In file included from ./boost/python/detail/config.hpp:15, from ./boost/python/detail/prefix.hpp:14, from ./boost/python/list.hpp:8, from libs/python/src/list.cpp:5: ./boost/config.hpp:35: fatal error: ./boost/boost/config/compiler/gcc.hpp: Too many levels of symbolic links compilation terminated. The file references are different, but the error is always the same. What have I done wrong? thanks, gary_p

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[asio] What have to be done to receive UDP broadcast packets?
by Michael Schulze 22 Mar '11

22 Mar '11

Hi list, I struggle with setting up an asio udp socket on Linux that is able to receive broadcasts. I managed the sending of broadcasts, but receiving seems to have a problem. I also managed sending and receiving of broadcasts with the native socket api of Linux. However, in the project we use asio to have portability across platforms and therewith we need to receive broadcast with asio too. The question is: How should an asio udp socket be setup in order to receive broadcasts? I did the following: udp::socket socket(io_service); socket.open(udp::v4()); boost::asio::socket_base::broadcast option(true); socket.set_option(option); socket.bind(udp::endpoint(address_v4::any(),8888)); and then I started receive_from. What is wrong with this? I did not receive the sent broadcast. Regards, Michael

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Cannot dlclose() module when including exception_ptr.hpp in GCC 4.5
by ichramm 22 Mar '11

22 Mar '11

Hi I'm having and issue with boost and gcc 4.5, I'm posting here before posting in the gcc mailing list 'cause it only happends if using boost. Thre following problem was tested with boost 1.44 and boost 1.46 (single and multi threaded) Situation: - Environment with GCC 4.5.2 (kernel 2-6-36 and 4.6.37, glibc 2.11 and 2.12 - C application that loads/unloads dynamic modules using dlopen/dlclose - C++ dynamic module compiled/linked agans boost::thread, and including <boost/exception_ptr> Problem: - dlclose() always returns zero, so the module is never unloaded Including <boost/thread/thread.hpp> or any other boost header works fine This only happends with GCC 4.5, so it could be a problem related to gcc, but I dnot know it yet. I'm attanching 3 small test files, so you can check if this happens on your machine, just execute 'make run' After reading the test application you say 'remove the while loop!', but the right behavior is that the second call to dlclose() should fail with 'shared object ot open'. Thanks in advance -- Saludos! :wq PS: Escuse my poor english :P

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