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

Can't call boost::fusion::invoke with >= 7 args
by Kevin Jenkins 21 Jul '08

21 Jul '08

Hi, First time poster. I found Boost over the weekend and have to say it's a great library! It's enabled me to do things in C++ I didn't think were possible before. I'm posting because I'm having a problem with boost::fusion::invoke. I'm using it to call a function with a list of predefined parameters. I found that if I have 6 or fewer parameters, everything compiles fine. If I have 7 or more parameters, it doesn't compile. I verified that it's not the parameters by removing the first 4 and leaving the last 5 (which was OK). Here's the code that I think is relevant: boost::fusion::invoke(func,args); Args is an iterator typename boost::mpl::begin< boost::function_types::parameter_types<Function> >::type func is a function pointer passed from C++ This is on Visual Studio 2005 using boost 1.35. I need at least 9 parameters. Thanks in advance! For reference, the output from the compiler is pasted below ---------------------- 1>c:\boost_1_35_0\boost\fusion\functional\invocation\invoke.hpp(102) : error C2504: 'boost::fusion::detail::invoke_impl<Function,Sequence,N,CBI,RandomAccess>' : base class undefined 1> with 1> [ 1> Function=void (__cdecl *)(A *,A &,C *,C &,D *,D &,NormalizedVector *,NormalizedVector &,RakNet::RPC3 *), 1> Sequence=const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::nil,const boost::fusion::single_view<A *>>,const boost::fusion::single_view<A>>,const boost::fusion::single_view<C *>>,const boost::fusion::single_view<C>>,const boost::fusion::single_view<D *>>,const boost::fusion::single_view<D>>,const boost::fusion::single_view<NormalizedVector *>>,const boost::fusion::single_view<NormalizedVector>>,const boost::fusion::single_view<RakNet::RPC3 *>>, 1> N=9, 1> CBI=false, 1> RandomAccess=false 1> ] 1> c:\boost_1_35_0\boost\fusion\functional\invocation\invoke.hpp(110) : see reference to class template instantiation 'boost::fusion::detail::invoke_nonmember_builtin<F,Sequence,N,RandomAccess>' being compiled 1> with 1> [ 1> F=void (__cdecl *)(A *,A &,C *,C &,D *,D &,NormalizedVector *,NormalizedVector &,RakNet::RPC3 *), 1> Sequence=const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::nil,const boost::fusion::single_view<A *>>,const boost::fusion::single_view<A>>,const boost::fusion::single_view<C *>>,const boost::fusion::single_view<C>>,const boost::fusion::single_view<D *>>,const boost::fusion::single_view<D>>,const boost::fusion::single_view<NormalizedVector *>>,const boost::fusion::single_view<NormalizedVector>>,const boost::fusion::single_view<RakNet::RPC3 *>>, 1> N=9, 1> RandomAccess=false 1> ] 1> c:\boost_1_35_0\boost\fusion\functional\invocation\invoke.hpp(159) : see reference to class template instantiation 'boost::fusion::detail::invoke_impl<Function,Sequence>' being compiled 1> with 1> [ 1> Function=void (__cdecl *)(A *,A &,C *,C &,D *,D &,NormalizedVector *,NormalizedVector &,RakNet::RPC3 *), 1> Sequence=const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::nil,const boost::fusion::single_view<A *>>,const boost::fusion::single_view<A>>,const boost::fusion::single_view<C *>>,const boost::fusion::single_view<C>>,const boost::fusion::single_view<D *>>,const boost::fusion::single_view<D>>,const boost::fusion::single_view<NormalizedVector *>>,const boost::fusion::single_view<NormalizedVector>>,const boost::fusion::single_view<RakNet::RPC3 *>> 1> ] 1> c:\raknet\dependentextensions\rpc3\rpc3_boost.h(261) : see reference to class template instantiation 'boost::fusion::result_of::invoke<Function,Sequence>' being compiled 1> with 1> [ 1> Function=void (__cdecl *)(A *,A &,C *,C &,D *,D &,NormalizedVector *,NormalizedVector &,RakNet::RPC3 *), 1> Sequence=const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::nil,const boost::fusion::single_view<A *>>,const boost::fusion::single_view<A>>,const boost::fusion::single_view<C *>>,const boost::fusion::single_view<C>>,const boost::fusion::single_view<D *>>,const boost::fusion::single_view<D>>,const boost::fusion::single_view<NormalizedVector *>>,const boost::fusion::single_view<NormalizedVector>>,const boost::fusion::single_view<RakNet::RPC3 *>> 1> ] 1> c:\raknet\dependentextensions\rpc3\rpc3_boost.h(247) : see reference to function template instantiation 'RakNet::_RPC3::InvokeResultCodes RakNet::_RPC3::BoostRPCInvoker<Function,From,To>::apply<boost::fusion::joint_view<Sequence1,Sequence2>>(Function,RakNet::_RPC3::InvokeArgs,const Args &)' being compiled 1> with 1> [ 1> Function=void (__cdecl *)(A *,A &,C *,C &,D *,D &,NormalizedVector *,NormalizedVector &,RakNet::RPC3 *), 1> From=next_iter_type, 1> To=boost::mpl::v_iter<boost::mpl::vector9<A *,A &,C *,C &,D *,D &,NormalizedVector *,NormalizedVector &,RakNet::RPC3 *>,9>, 1> Sequence1=const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::nil,const boost::fusion::single_view<A *>>,const boost::fusion::single_view<A>>,const boost::fusion::single_view<C *>>,const boost::fusion::single_view<C>>,const boost::fusion::single_view<D *>>,const boost::fusion::single_view<D>>,const boost::fusion::single_view<NormalizedVector *>>,const boost::fusion::single_view<NormalizedVector>>, 1> Sequence2=const boost::fusion::single_view<RakNet::RPC3 *>, 1> Args=boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::nil,const boost::fusion::single_view<A *>>,const boost::fusion::single_view<A>>,const boost::fusion::single_view<C *>>,const boost::fusion::single_view<C>>,const boost::fusion::single_view<D *>>,const boost::fusion::single_view<D>>,const boost::fusion::single_view<NormalizedVector *>>,const boost::fusion::single_view<NormalizedVector>>,const boost::fusion::single_view<RakNet::RPC3 *>> 1> ] 1> c:\raknet\dependentextensions\rpc3\rpc3_boost.h(247) : see reference to function template instantiation 'RakNet::_RPC3::InvokeResultCodes RakNet::_RPC3::BoostRPCInvoker<Function,From,To>::apply<boost::fusion::joint_view<Sequence1,Sequence2>>(Function,RakNet::_RPC3::InvokeArgs,const Args &)' being compiled 1> with 1> [ 1> Function=void (__cdecl *)(A *,A &,C *,C &,D *,D &,NormalizedVector *,NormalizedVector &,RakNet::RPC3 *), 1> From=next_iter_type, 1> To=boost::mpl::v_iter<boost::mpl::vector9<A *,A &,C *,C &,D *,D &,NormalizedVector *,NormalizedVector &,RakNet::RPC3 *>,9>, 1> Sequence1=const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::nil,const boost::fusion::single_view<A *>>,const boost::fusion::single_view<A>>,const boost::fusion::single_view<C *>>,const boost::fusion::single_view<C>>,const boost::fusion::single_view<D *>>,const boost::fusion::single_view<D>>,const boost::fusion::single_view<NormalizedVector *>>, 1> Sequence2=const boost::fusion::single_view<NormalizedVector>, 1> Args=boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::nil,const boost::fusion::single_view<A *>>,const boost::fusion::single_view<A>>,const boost::fusion::single_view<C *>>,const boost::fusion::single_view<C>>,const boost::fusion::single_view<D *>>,const boost::fusion::single_view<D>>,const boost::fusion::single_view<NormalizedVector *>>,const boost::fusion::single_view<NormalizedVector>> 1> ] 1> c:\raknet\dependentextensions\rpc3\rpc3_boost.h(247) : see reference to function template instantiation 'RakNet::_RPC3::InvokeResultCodes RakNet::_RPC3::BoostRPCInvoker<Function,From,To>::apply<boost::fusion::joint_view<Sequence1,Sequence2>>(Function,RakNet::_RPC3::InvokeArgs,const Args &)' being compiled 1> with 1> [ 1> Function=void (__cdecl *)(A *,A &,C *,C &,D *,D &,NormalizedVector *,NormalizedVector &,RakNet::RPC3 *), 1> From=next_iter_type, 1> To=boost::mpl::v_iter<boost::mpl::vector9<A *,A &,C *,C &,D *,D &,NormalizedVector *,NormalizedVector &,RakNet::RPC3 *>,9>, 1> Sequence1=const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::nil,const boost::fusion::single_view<A *>>,const boost::fusion::single_view<A>>,const boost::fusion::single_view<C *>>,const boost::fusion::single_view<C>>,const boost::fusion::single_view<D *>>,const boost::fusion::single_view<D>>, 1> Sequence2=const boost::fusion::single_view<NormalizedVector *>, 1> Args=boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::nil,const boost::fusion::single_view<A *>>,const boost::fusion::single_view<A>>,const boost::fusion::single_view<C *>>,const boost::fusion::single_view<C>>,const boost::fusion::single_view<D *>>,const boost::fusion::single_view<D>>,const boost::fusion::single_view<NormalizedVector *>> 1> ] 1> c:\raknet\dependentextensions\rpc3\rpc3_boost.h(247) : see reference to function template instantiation 'RakNet::_RPC3::InvokeResultCodes RakNet::_RPC3::BoostRPCInvoker<Function,From,To>::apply<boost::fusion::joint_view<Sequence1,Sequence2>>(Function,RakNet::_RPC3::InvokeArgs,const Args &)' being compiled 1> with 1> [ 1> Function=void (__cdecl *)(A *,A &,C *,C &,D *,D &,NormalizedVector *,NormalizedVector &,RakNet::RPC3 *), 1> From=next_iter_type, 1> To=boost::mpl::v_iter<boost::mpl::vector9<A *,A &,C *,C &,D *,D &,NormalizedVector *,NormalizedVector &,RakNet::RPC3 *>,9>, 1> Sequence1=const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::nil,const boost::fusion::single_view<A *>>,const boost::fusion::single_view<A>>,const boost::fusion::single_view<C *>>,const boost::fusion::single_view<C>>,const boost::fusion::single_view<D *>>, 1> Sequence2=const boost::fusion::single_view<D>, 1> Args=boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::nil,const boost::fusion::single_view<A *>>,const boost::fusion::single_view<A>>,const boost::fusion::single_view<C *>>,const boost::fusion::single_view<C>>,const boost::fusion::single_view<D *>>,const boost::fusion::single_view<D>> 1> ] 1> c:\raknet\dependentextensions\rpc3\rpc3_boost.h(247) : see reference to function template instantiation 'RakNet::_RPC3::InvokeResultCodes RakNet::_RPC3::BoostRPCInvoker<Function,From,To>::apply<boost::fusion::joint_view<Sequence1,Sequence2>>(Function,RakNet::_RPC3::InvokeArgs,const Args &)' being compiled 1> with 1> [ 1> Function=void (__cdecl *)(A *,A &,C *,C &,D *,D &,NormalizedVector *,NormalizedVector &,RakNet::RPC3 *), 1> From=next_iter_type, 1> To=boost::mpl::v_iter<boost::mpl::vector9<A *,A &,C *,C &,D *,D &,NormalizedVector *,NormalizedVector &,RakNet::RPC3 *>,9>, 1> Sequence1=const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::nil,const boost::fusion::single_view<A *>>,const boost::fusion::single_view<A>>,const boost::fusion::single_view<C *>>,const boost::fusion::single_view<C>>, 1> Sequence2=const boost::fusion::single_view<D *>, 1> Args=boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::nil,const boost::fusion::single_view<A *>>,const boost::fusion::single_view<A>>,const boost::fusion::single_view<C *>>,const boost::fusion::single_view<C>>,const boost::fusion::single_view<D *>> 1> ] 1> c:\raknet\dependentextensions\rpc3\rpc3_boost.h(247) : see reference to function template instantiation 'RakNet::_RPC3::InvokeResultCodes RakNet::_RPC3::BoostRPCInvoker<Function,From,To>::apply<boost::fusion::joint_view<Sequence1,Sequence2>>(Function,RakNet::_RPC3::InvokeArgs,const Args &)' being compiled 1> with 1> [ 1> Function=void (__cdecl *)(A *,A &,C *,C &,D *,D &,NormalizedVector *,NormalizedVector &,RakNet::RPC3 *), 1> From=next_iter_type, 1> To=boost::mpl::v_iter<boost::mpl::vector9<A *,A &,C *,C &,D *,D &,NormalizedVector *,NormalizedVector &,RakNet::RPC3 *>,9>, 1> Sequence1=const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::nil,const boost::fusion::single_view<A *>>,const boost::fusion::single_view<A>>,const boost::fusion::single_view<C *>>, 1> Sequence2=const boost::fusion::single_view<C>, 1> Args=boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::nil,const boost::fusion::single_view<A *>>,const boost::fusion::single_view<A>>,const boost::fusion::single_view<C *>>,const boost::fusion::single_view<C>> 1> ] 1> c:\raknet\dependentextensions\rpc3\rpc3_boost.h(247) : see reference to function template instantiation 'RakNet::_RPC3::InvokeResultCodes RakNet::_RPC3::BoostRPCInvoker<Function,From,To>::apply<boost::fusion::joint_view<Sequence1,Sequence2>>(Function,RakNet::_RPC3::InvokeArgs,const Args &)' being compiled 1> with 1> [ 1> Function=void (__cdecl *)(A *,A &,C *,C &,D *,D &,NormalizedVector *,NormalizedVector &,RakNet::RPC3 *), 1> From=next_iter_type, 1> To=boost::mpl::v_iter<boost::mpl::vector9<A *,A &,C *,C &,D *,D &,NormalizedVector *,NormalizedVector &,RakNet::RPC3 *>,9>, 1> Sequence1=const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::nil,const boost::fusion::single_view<A *>>,const boost::fusion::single_view<A>>, 1> Sequence2=const boost::fusion::single_view<C *>, 1> Args=boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::nil,const boost::fusion::single_view<A *>>,const boost::fusion::single_view<A>>,const boost::fusion::single_view<C *>> 1> ] 1> c:\raknet\dependentextensions\rpc3\rpc3_boost.h(247) : see reference to function template instantiation 'RakNet::_RPC3::InvokeResultCodes RakNet::_RPC3::BoostRPCInvoker<Function,From,To>::apply<boost::fusion::joint_view<Sequence1,Sequence2>>(Function,RakNet::_RPC3::InvokeArgs,const Args &)' being compiled 1> with 1> [ 1> Function=void (__cdecl *)(A *,A &,C *,C &,D *,D &,NormalizedVector *,NormalizedVector &,RakNet::RPC3 *), 1> From=next_iter_type, 1> To=boost::mpl::v_iter<boost::mpl::vector9<A *,A &,C *,C &,D *,D &,NormalizedVector *,NormalizedVector &,RakNet::RPC3 *>,9>, 1> Sequence1=const boost::fusion::joint_view<const boost::fusion::nil,const boost::fusion::single_view<A *>>, 1> Sequence2=const boost::fusion::single_view<A>, 1> Args=boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::nil,const boost::fusion::single_view<A *>>,const boost::fusion::single_view<A>> 1> ] 1> c:\raknet\dependentextensions\rpc3\rpc3_boost.h(247) : see reference to function template instantiation 'RakNet::_RPC3::InvokeResultCodes RakNet::_RPC3::BoostRPCInvoker<Function,From,To>::apply<boost::fusion::joint_view<Sequence1,Sequence2>>(Function,RakNet::_RPC3::InvokeArgs,const Args &)' being compiled 1> with 1> [ 1> Function=void (__cdecl *)(A *,A &,C *,C &,D *,D &,NormalizedVector *,NormalizedVector &,RakNet::RPC3 *), 1> From=next_iter_type, 1> To=boost::mpl::v_iter<boost::mpl::vector9<A *,A &,C *,C &,D *,D &,NormalizedVector *,NormalizedVector &,RakNet::RPC3 *>,9>, 1> Sequence1=const boost::fusion::nil, 1> Sequence2=const boost::fusion::single_view<A *>, 1> Args=boost::fusion::joint_view<const boost::fusion::nil,const boost::fusion::single_view<A *>> 1> ] 1> c:\raknet\dependentextensions\rpc3\rpc3_boost.h(336) : see reference to function template instantiation 'RakNet::_RPC3::InvokeResultCodes RakNet::_RPC3::BoostRPCInvoker<Function>::apply<boost::fusion::nil>(Function,RakNet::_RPC3::InvokeArgs,const Args &)' being compiled 1> with 1> [ 1> Function=void (__cdecl *)(A *,A &,C *,C &,D *,D &,NormalizedVector *,NormalizedVector &,RakNet::RPC3 *), 1> Args=boost::fusion::nil 1> ] 1> c:\raknet\dependentextensions\rpc3\rpc3_boost.h(335) : while compiling class template member function 'RakNet::_RPC3::FunctionPointer RakNet::_RPC3::GetBoundPointer_C<Function>::GetBoundPointer(Function)' 1> with 1> [ 1> Function=void (__cdecl *)(A *,A &,C *,C &,D *,D &,NormalizedVector *,NormalizedVector &,RakNet::RPC3 *) 1> ] 1> c:\raknet\dependentextensions\rpc3\rpc3_boost.h(355) : see reference to class template instantiation 'RakNet::_RPC3::GetBoundPointer_C<Function>' being compiled 1> with 1> [ 1> Function=void (__cdecl *)(A *,A &,C *,C &,D *,D &,NormalizedVector *,NormalizedVector &,RakNet::RPC3 *) 1> ] 1> c:\raknet\dependentextensions\rpc3\rpc3.h(100) : see reference to function template instantiation 'RakNet::_RPC3::FunctionPointer RakNet::_RPC3::GetBoundPointer<void(__cdecl *)(A *,A &,C *,C &,D *,D &,NormalizedVector *,NormalizedVector &,RakNet::RPC3 *)>(Function)' being compiled 1> with 1> [ 1> Function=void (__cdecl *)(A *,A &,C *,C &,D *,D &,NormalizedVector *,NormalizedVector &,RakNet::RPC3 *) 1> ] 1> c:\raknet\samples\rpc3\rpc3sample.cpp(127) : see reference to function template instantiation 'bool RakNet::RPC3::RegisterFunction<void(__cdecl *)(A *,A &,C *,C &,D *,D &,NormalizedVector *,NormalizedVector &,RakNet::RPC3 *)>(const char *,Function)' being compiled 1> with 1> [ 1> Function=void (__cdecl *)(A *,A &,C *,C &,D *,D &,NormalizedVector *,NormalizedVector &,RakNet::RPC3 *) 1> ] 1>c:\boost_1_35_0\boost\fusion\functional\invocation\invoke.hpp(159) : error C2039: 'result_type' : is not a member of 'boost::fusion::detail::invoke_impl<Function,Sequence>' 1> with 1> [ 1> Function=void (__cdecl *)(A *,A &,C *,C &,D *,D &,NormalizedVector *,NormalizedVector &,RakNet::RPC3 *), 1> Sequence=const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::joint_view<const boost::fusion::nil,const boost::fusion::single_view<A *>>,const boost::fusion::single_view<A>>,const boost::fusion::single_view<C *>>,const boost::fusion::single_view<C>>,const boost::fusion::single_view<D *>>,const boost::fusion::single_view<D>>,const boost::fusion::single_view<NormalizedVector *>>,const boost::fusion::single_view<NormalizedVector>>,const boost::fusion::single_view<RakNet::RPC3 *>> 1> ] 1>c:\boost_1_35_0\boost\fusion\functional\invocation\invoke.hpp(159) : error C2146: syntax error : missing ';' before identifier 'type' 1>c:\boost_1_35_0\boost\fusion\functional\invocation\invoke.hpp(159) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int 1>c:\boost_1_35_0\boost\fusion\functional\invocation\invoke.hpp(159) : error C2208: 'boost::type' : no members defined using this type 1>c:\boost_1_35_0\boost\fusion\functional\invocation\invoke.hpp(159) : fatal error C1903: unable to recover from previous error(s); stopping compilation

3 3

Random numbers
by Olivier Tournaire 21 Jul '08

21 Jul '08

Hi all, I am currently using boost::random, and I wonder how it is possible to get uniform random numbers on a union of two intervalls. For instance, I would like to generate uniform_real numbers in the intervall [-a;-b]U[b;a]. How can I do such a task ? Best regards, Olivier Tournaire

3 5

[bind][lambda] overriding return value
by David Rodríguez Ibeas 21 Jul '08

21 Jul '08

Hi, Is it possible to override/generate a return value? I want to connect a signal that has a bool return value to a method that has a void return type, generating always a true return. class X { public: void f(); }; boost::signal< bool () > sgn; X x; sgn.connect( boost::bind( &X::f, &x ) ); // error, signal has bool return, method doesn't David

3 2

ImportError: dynamic module does not define init function
by Tony May 21 Jul '08

21 Jul '08

I get the following error when trying to import a pyd file in python. I'm trying to use this with the Delta3D game engine to access VRPN data. ------ Traceback (most recent call last): File "hello.py", line 2, in <module> import PyVrpnData ImportError: dynamic module does not define init function (initPyVrpnData) ------ Here's the python file. ------ import PyVrpnData print "hello" print PyVrpnData.getPos(1) print "done" ------ I'm trying to use boost but not use bjam as it appears Delta3D has done. Here is the source. -------- float getPos(int i); float getQuat(int i); void initPyVrpnData() { using namespace boost::python; def("getPos",getPos); def("getQuat",getQuat); } ------- #include <boost/python.hpp> extern "C" __declspec(dllexport) void initPyVrpnData(); BOOST_PYTHON_MODULE(PyVrpnData) { initPyVrpnData(); } --------

1 0

Problem with type traits
by Robert Dailey 21 Jul '08

21 Jul '08

Hi, I'm trying to create my own struct that is compatible with boost::mpl::or_ as well as boost::enable_if. I find that using boost::mpl::or_ requires that my structure have a 'type' member, and enable_if looks for 'value'. Must I define both? What is the proper way to handle this? Below is my structure: template< typename t_type > struct is_sink { typedef typename boost::mpl::or_< vfx::io::is_device<t_type>, boost::is_same<t_type, vfx::io::Sink> > type; }; The above structure works perfectly fine with boost::mpl::or_, but does not work for boost::enable_if because it is looking for a 'value' member. I feel what it should be looking for is is_sink::type::value. An example of how I use the above structure is below: template< typename t_source, typename t_data > typename boost::enable_if< boost::mpl::and_<*is_source<t_source>*, boost::is_pod<t_data> >, t_source >::type& operator>> ( t_source& source, t_data& data ) { source.Read( reinterpret_cast<boost::uint8_t*>( &data ), sizeof( t_data ) ); return source; }

4 6

"invalid next size" in lu_factorize
by Sylvain Bertrand 21 Jul '08

21 Jul '08

Hi, When running lu_factorize() on a 10x10 matrix, I get the following message and have no clue of the reason why (googling or searching this ML didn't help). *** glibc detected *** ./a.out: free(): invalid next size (normal): 0x0806b8a0 *** ======= Backtrace: ========= /lib/i686/cmov/libc.so.6[0xb7d068f5] /lib/i686/cmov/libc.so.6(cfree+0x90)[0xb7d0a360] /usr/lib/libstdc++.so.6(_ZdlPv+0x21)[0xb7ed4171] ./a.out[0x805d28d] ./a.out[0x8058969] ./a.out[0x8051bcd] ./a.out[0x8057481] ./a.out[0x8057632] ./a.out(__gxx_personality_v0+0x317)[0x804adf7] /lib/i686/cmov/libc.so.6(__libc_start_main+0xe0)[0xb7cb1450] ./a.out(__gxx_personality_v0+0xb1)[0x804ab91] ======= Memory map: ======== Any help is appreciated. Regards, Sylvain

1 1

[lambda] Exploring bind syntax.
by Robert Jones 21 Jul '08

21 Jul '08

Using the code snippet below as an example,... #include <vector> #include <algorithm> #include <functional> #include "boost/lambda/lambda.hpp" #include "boost/lambda/bind.hpp" #include <boost/function.hpp> struct S { int methodOfS( ); }; int main( ) { typedef std :: vector<S *> Vec; using namespace boost :: lambda; boost :: function<int( S * )> fn = bind( & S :: methodOfS, _1 ); Vec v; Vec :: iterator match; match = find_if( v.begin( ), v.end( ), bind( fn, _1 ) != fn( * v.begin( ) ) ); // OK match = find_if( v.begin( ), v.end( ), fn( _1 ) != fn( * v.begin( ) ) ); // Fail } I find the line marked 'OK' compiles, but not the line marked 'Fail'. Isn't the very point of Boost.Bind to enable this kind of syntax? Is there a better way to write it than my 'Fail' line, but which will still compile? Thanks, Rob. -- ACCU - Professionalism in programming - http://www.accu.org

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[serialization] Problems with BOOST_IS_ABSTRACT, gcc 3.2.3 and Boost 1.35.0
by Dan Thomas 21 Jul '08

21 Jul '08

Hi If I use gcc 3.2.3 (Linux) and Boost 1.35.0 to compile the example program at... http://lists.boost.org/boost-users/att-26574/test_serialize.cpp ...I get extensive compile errors which I can summarise as: <path>/boost_1_35_0/boost/serialization/export.hpp:125: `instantiate' is not a member of type `boost::archive::detail::ptr_serialization_support<boost::archive::text_iarchive, base>' These errors do not occur if I use either Boost 1.33.0 or Microsoft Visual Studio. The fact that the test program's base class is abstract seems to be central to the problem. The error is eliminated if I remove the BOOST_IS_ABSTRACT(base) statement from the test program. Doing so naturally causes other problems but these are in turn fixed by making "base" concrete i.e. by removing the =0 qualifier from base::get_id() and providing an implementation. It looks as if code in Boost 1.35.0 expects all classes to provide an instantiate method, even though the method is not in fact present on classes that have been marked as abstract. Is there any chance of a fix or work-around? Many Thanks Dan

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[lambda] Writing pass-through 'standard' algorithms
by Robert Jones 21 Jul '08

21 Jul '08

I encountered this difficulty in the context of passing lambda functors, but on reflection I don't the lambda aspect particularly matters. Consider this templated function template <typename InputIterator, typename Predicate> inline bool all_if( InputIterator first, InputIterator last, Predicate predicate ) { return std :: find_if( first, last, std :: not1( predicate ) ) == last; } Obviously the intent is to enquire if all members of a range satisfy the predicate. Now, as is, this doesn't compile, because it needs ptr_fun() on the predicate, but then a couple of things come up. - ptr_fun( ) requires that it's argument is a pointer-to-function - I'd like my all_if( ) to permit functions or functors, including lambda functors How can this be done? Is it impossible to dress-up a standard algorithm in this way? Thanks, Rob. -- ACCU - Professionalism in programming - http://www.accu.org

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Re: [Boost-users] question on boost-compliant code conventions
by Alan M. Carroll 21 Jul '08

21 Jul '08

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