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[boost.python] void pointer argument problem
by michael_gruner＠arcor.de 06 Aug '06

06 Aug '06

Hello, I'm trying to use boost.python to wrap a C function that takes a pointer on a void pointer as an argument. But I'm going wrong to use the example from the FAQ. Could anyone help me on this? my code looks like this: struct void_; BOOST_PYTHON_OPAQUE_SPECIALIZED_TYPE_ID(void_); int myfunc(char * mychar, void ** mypointer); int myfunc_wrp(char * mychar, void_ ** mypointer){ return myfunc(mychar,(void ** ) mypointer); } ... BOOST_PYTHON_MODULE(mymodule){ def("myfunc", &myfunc_wrp); } later in python I do: import mymodule mystring = " " mypointerobject = 0 mymodule.myfunc(mystring,mypointerobject) and get: Boost.Python.ArgumentError: Python argument types in mymodule.myfunc(str, int) did not match C++ signature: myfunc(char *, struct void_ * *) Are there any advices to solve this problem? thank you for your answers. Kind regards, Michael

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using filesystem library
by Fred J. 06 Aug '06

06 Aug '06

hi this is given me some error I cannot locate a fix. thanks **************** code **************** #include <iostream> #include <string> #include "boost/filesystem/operations.hpp" // includes boost/filesystem/path.hpp #include "boost/filesystem/fstream.hpp" namespace fs = boost::filesystem; using namespace std; int main(){ fs::path full_path("../data"); if (exists(full_path)) cout << "yes" << endl; } //there exists data directory in the parent of the current directory. **************** error **************** $ make g++ -gdwarf-2 -c -o try.o try.cpp g++ -Wall -gdwarf-2 -o proj try.o try.o: In function `main': /home/fred/myPrograms/backtest/try/try.cpp:11: undefined reference to `boost::filesystem::path::path(char const*)' /home/fred/myPrograms/backtest/try/try.cpp:12: undefined reference to `boost::filesystem::exists(boost::filesystem::path const&)' collect2: ld returned 1 exit status make: *** [proj] Error 1 __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

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[regex] compile issue
by Thomas Matelich 06 Aug '06

06 Aug '06

Finally got around to upgrading to 1.33.1 on HP 11i, g++ 4.1.1. in v4/regex_traits_defaults.hpp, the compiler was not happy with the WCHAR_MIN == 0 and WCHAR_MAX <= USHRT_MAX checks. This appears to be due to their definition: #define WCHAR_MIN (wchar_t)0 #define WCHAR_MAX (wchar_t)UINT_MAX I tried a few things I could think of, but ended up undef'ing and redefining them without the (wchar_t). Tom Matelich

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Re: [Boost-users] Boost.Signals example/doc_view application question
by Wu Yinghui, Freddie 05 Aug '06

05 Aug '06

[snip] > The View abstract base class requires concrete bases to provide a > concrete implementation of the refresh() member function matching the > slot signature required. > > class View > { > public: > virtual void refresh(bool) const = 0; > // ... > }; > > Here's my problem. If I change the signal to take no args using the > preferred or portable syntax I get compilation errors: > > class Document > { > public: > typedef boost::signal< void () > signal_t; > // ... > > void append(const char* s) > { > m_text += s; > m_sig(true); You should use m_sig(); instead! > } > // ... > }; > > class View > { > public: > virtual void refresh() const = 0; > // ... > }; > > Compilation output (msvc-7.1): > > Compiling... > SignalTest.cpp > c:\Boost\include\boost-1_33_1\boost\bind.hpp(63) : error C2825: > 'F::result_type': cannot form a qualified name > c:\Boost\include\boost-1_33_1\boost\bind\bind_template.hpp(15) : > see reference to class template instantiation > 'boost::_bi::result_traits<R,F>' being compiled > with > [ > R=boost::_bi::unspecified, > F=void (__thiscall View::* )(void) const > ] > c:\development\SignalTest\SignalTest.cpp(49) : see reference to > class template instantiation 'boost::_bi::bind_t<R,F,L>' being compiled > with > [ > R=boost::_bi::unspecified, > F=void (__thiscall View::* )(void) const, > L=boost::_bi::list2<boost::_bi::list_av_2<View > *,boost::arg<1>>::B1,boost::_bi::list_av_2<View *,boost::arg<1>>::B2> > ] > c:\Boost\include\boost-1_33_1\boost\bind.hpp(63) : error C2039: > 'result_type' : is not a member of 'operator``global namespace''' > c:\Boost\include\boost-1_33_1\boost\bind.hpp(63) : error C2146: syntax > error : missing ';' before identifier 'type' > c:\Boost\include\boost-1_33_1\boost\bind.hpp(63) : error C2955: > 'boost::_bi::type' : use of class template requires template argument list > c:\Boost\include\boost-1_33_1\boost\bind.hpp(112) : see > declaration of 'boost::_bi::type' > c:\Boost\include\boost-1_33_1\boost\bind.hpp(63) : fatal error C1903: > unable to recover from previous error(s); stopping compilation Cheers, Freddie

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Testing Program Output
by Paulo J. Matos 05 Aug '06

05 Aug '06

Hi all, Is there support in Boost for testing program output, which depends exclusively in its arguments? Briefly, my program is not-interactive and its result (to stdout) depends uniquely on its input argument. Is there anything in Boost that can help me test my program this way? I've been using the Unit Testing Framework for unit tests and for the tests I've mentioned I've only found dejagnu up until now. Another solution would be bash-scripts that would run the program and check output, but that's not nice enough for me. Anything in Boost I might use? If not, are there any other suggestions? Cheers, -- Paulo Jorge Matos - pocm at sat inesc-id pt Web: http://sat.inesc-id.pt/~pocm Computer and Software Engineering INESC-ID - SAT Group

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[BGL] connected components algorithm
by Alejandro Aragon 05 Aug '06

05 Aug '06

Hello everyone. I'm trying to implement Fleury's algorithm to find an Eulerian path in a graph. Every time I erase an edge in the graph, I need to check how many connected components I have (because I can't erase an edge that is a "bridge"). Also, I was using in the beginning graphs with VertexList=VecS but it turns out that when you erase an edge all the vertex descriptors are invalidated. Thus, I had to copy my graph to another one with VertexList=listS. I was wondering if the connected components algorithm works with this type of graph. I'm having an error. It seems that the compiler does not recognize this function. /usr/include/boost/graph/connected_components.hpp:46: error: no matching function for call to ‘put(unsigned int*&, void*&, unsigned int&)’ make: *** [graph.o] Error 1 Any ideas? Thank you, aa My code is shown below: typedef adjacency_list<listS, listS, undirectedS, property<vertex_index_t, std::size_t>, no_property > graph_t; graph_traits<graph_t>::out_edge_iterator out,out_end; graph_t copy(num_vertices(*gPtr)); // obtain a property map for the vertex_index property property_map<graph_t, vertex_index_t>::type index = get(vertex_index, copy); // initialize the vertex_index property values graph_traits<graph_t>::vertex_iterator vi, vend; graph_traits<graph_t>::vertices_size_type cnt = 0; for(tie(vi,vend) = vertices(copy); vi != vend; ++vi) put(index, *vi, cnt++); for (tie(ei, ei_end) = edges(*gPtr); ei != ei_end; ++ei){ add_edge(vertex(source(*ei,*gPtr), copy), vertex(target(*ei,*gPtr), copy), copy); } graph_traits<graph_t>::vertex_descriptor Vertex; graph_traits<graph_t>::edge_iterator ei,ei_end; vertex_descriptor u,v; u = vertex(0,copy); for (tie(out, out_end) = out_edges(u,copy); out != out_end; ++out){ u = source(*out,copy); v = target(*out,copy); remove_edge(u,v,copy); std::vector<size_t> component(num_vertices(copy)); num = connected_components(copy, &component[0]);

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Jim Lear is out of the office.
by Jim.Lear＠legerity.com 05 Aug '06

05 Aug '06

I will be out of the office starting 08/05/2006 and will not return until 08/12/2006. I will respond to your message when I return.

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assert when using cregex_iterator
by Winson Yung 05 Aug '06

05 Aug '06

I have a very simple test program using the latest 1.33 version of regex library. As soon as I run it, it assert (crash) at the line where std::string s = (*m1)[0]. I am doing something wrong? ============== #include "stdafx.h" #include <boost/regex.hpp> const char matchpattern[] = "\\s+kitty this"; const char astring[] = "hello Kitty this is a test"; using namespace boost; int main(int argc, char* argv[]) { regex header_expr(matchpattern, regex_constants::basic | regex_constants::icase); cregex_iterator m1(astring, astring + strlen(astring), header_expr); std::string s = (*m1)[0]; <==== crash here return 0; }

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boost python noobie questions
by chun ping wang 05 Aug '06

05 Aug '06

Hey I have several problem... A.) Can boost::python work with templated argument... Example: /************************************************ * rsa(p, q): * * let n = p * q * * let totient = (p-1)*(q-1) * * choose integer e between 1 and totient * * such that greatest common denominator is 1 * * d = (1 mod totient) / e * * return e, d, n * ************************************************/ template <class T> boost::tuple<T, T, T> boost::rsa_generate(const T& p, const T& q) { BOOST_STATIC_ASSERT(boost::is_integral<T>::value); assert(p != q); const T n(p*q); const T totient((p-1)*(q-1)); T e(3); for (e; EuclidBinaryGCD(e, totient) != 1; e = Random::randint(T(2), totient-1)); const T d(Inversemod(e, totient)); return boost::make_tuple(e, d, n); } BOOST_PYTHON_MODULE(rsa) { def("rsa_generate", boost::rsa_generate); } Second question.. how come lambda function don't work. COmpling this by itself..give no error. template <class T, template <typename ELEM, typename = std::allocator<ELEM> > class CONT> double MyAnn::getCondProb(const T& A, const T& B, const CONT<typename std::pair<T, T> >& DATA) { using namespace boost::lambda; typedef typename std::pair<T, T> MyPair; // gets the number of B const int numOfB ( std::count_if(DATA.begin(), DATA.end(), bind(&MyPair::second, _1) == B ) ); // gets the number of A given B. const int numOfAGivenB( std::count_if(DATA.begin(), DATA.end(), (bind(&MyPair::second, _1) == B) && (bind(&MyPair::first, _1) == A) ) ); return (numOfAGivenB*1.0)/numOfB; } now including this file.. and compling this gives error about "_1" BOOST_PYTHON_MODULE(bayesian) { def ("getCondProb", getCondProb<long long>); } Thanks for the help. If its the way i compile.. how i would i get it to work.. iam using dev-cpp 4.9

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Boost.Signals example/doc_view application question
by Allen Gooch 04 Aug '06

04 Aug '06

I have a quick question regarding connecting a bound member function. In the doc_view example application signals are defined as requiring a function taking a bool and returning nothing. class Document { public: typedef boost::signal< void (bool) > signal_t; // ... void append(const char* s) { m_text += s; m_sig(true); } // ... }; The View abstract base class requires concrete bases to provide a concrete implementation of the refresh() member function matching the slot signature required. class View { public: virtual void refresh(bool) const = 0; // ... }; Here's my problem. If I change the signal to take no args using the preferred or portable syntax I get compilation errors: class Document { public: typedef boost::signal< void () > signal_t; // ... void append(const char* s) { m_text += s; m_sig(true); } // ... }; class View { public: virtual void refresh() const = 0; // ... }; Compilation output (msvc-7.1): Compiling... SignalTest.cpp c:\Boost\include\boost-1_33_1\boost\bind.hpp(63) : error C2825: 'F::result_type': cannot form a qualified name c:\Boost\include\boost-1_33_1\boost\bind\bind_template.hpp(15) : see reference to class template instantiation 'boost::_bi::result_traits<R,F>' being compiled with [ R=boost::_bi::unspecified, F=void (__thiscall View::* )(void) const ] c:\development\SignalTest\SignalTest.cpp(49) : see reference to class template instantiation 'boost::_bi::bind_t<R,F,L>' being compiled with [ R=boost::_bi::unspecified, F=void (__thiscall View::* )(void) const, L=boost::_bi::list2<boost::_bi::list_av_2<View *,boost::arg<1>>::B1,boost::_bi::list_av_2<View *,boost::arg<1>>::B2> ] c:\Boost\include\boost-1_33_1\boost\bind.hpp(63) : error C2039: 'result_type' : is not a member of 'operator``global namespace''' c:\Boost\include\boost-1_33_1\boost\bind.hpp(63) : error C2146: syntax error : missing ';' before identifier 'type' c:\Boost\include\boost-1_33_1\boost\bind.hpp(63) : error C2955: 'boost::_bi::type' : use of class template requires template argument list c:\Boost\include\boost-1_33_1\boost\bind.hpp(112) : see declaration of 'boost::_bi::type' c:\Boost\include\boost-1_33_1\boost\bind.hpp(63) : fatal error C1903: unable to recover from previous error(s); stopping compilation Observed with boost_1_33_1 release on cygwin/gcc-3.4.4 and msvc-7.1 platforms. Any ideas? Many thanks in advance, -allen

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