Hi, I am wondering if anyone has a working example of exposing std::pair as a Python tuple or list. Technically, I need to expose a vector of tuples and the following works class_<std::vector<std::pair<std::string, double> > >("VectorPair") .def(vector_indexing_suite<std::vector<std::pair<std::string, double> > >()) ; but I am not sure how then to expose the std::pair. I am guessing I should use boost/python/tuple.hpp or list.hpp but can't figure out the syntax. Thanks in advance.
I think I can partially answer your question. Although I don't know how to expose std::pair using indexing suite, thanks to Roman Yakovenko and his Py++ package, I can show you working example of exporting pair using different approach: This is *.h file with class containing variable of type std::pair<int, int> to be exposed (this file is also available here: http://pygccxml.svn.sourceforge.net/viewvc/pygccxml?view=rev): // Copyright 2004-2008 Roman Yakovenko. // Distributed under the Boost Software License, Version 1.0. (See // accompanying file LICENSE_1_0.txt or copy at // http://www.boost.org/LICENSE_1_0.txt) #ifndef __std_pair_to_be_exported_hpp__ #define __std_pair_to_be_exported_hpp__ #include <utility> struct tester_t{ tester_t(int a, int b){ pair_.first = a; pair_.second = b; } int compute(){return pair_.first + pair_.second;} std::pair<int, int> pair_; }; #endif//__std_pair_to_be_exported_hpp__ And here is wrapper code generated by Py++: // This file has been generated by Py++. // Copyright 2004-2008 Roman Yakovenko. // Distributed under the Boost Software License, Version 1.0. (See // accompanying file LICENSE_1_0.txt or copy at // http://www.boost.org/LICENSE_1_0.txt) #include "boost/python.hpp" #include "std_pair_to_be_exported.hpp" namespace bp = boost::python; BOOST_PYTHON_MODULE(std_pair){ bp::class_< std::pair< int, int > >( "pair_less__int_comma__int__greater_", "documentation", bp::init<
("documentation") ) .def( bp::init< int const &, int const & >(( bp::arg("__a"), bp::arg("__b") ), "documentation") ) .def_readwrite( "first", &std::pair< int, int >::first, "documentation" ) .def_readwrite( "second", &std::pair< int, int >::second, "documentation" );
bp::class_< tester_t >( "tester_t", "documentation", bp::init< int, int >(( bp::arg("a"), bp::arg("b") ), "documentation") ) .def( "compute" , (int ( ::tester_t::* )( ) )( &::tester_t::compute ) , "documentation" ) .def_readwrite( "pair_", &tester_t::pair_, "documentation" ); } You should notice that in python: pairA = module.pair_less__int_comma__int__greater_(2,3) pairB = module.pair_less__int_comma__int__greater_(2,3) pairA.first == pairB.first
True
pairA.second == pairB.second
True
BUT: pairA == pairB
False
I'm also interested in exposing std::pair using indexing suite because it perhaps make statement pairA == pairB become true. Especially if that code would be auto-generated by Py++ just like other STL containers it could be very useful. Roman Yakovenko wrote there is a chance this functionality would be added in next release of Py++. Also you can ask this question on Cplusplus-sig mailing list: http://mail.python.org/mailman/listinfo/cplusplus-sig If you find accurate answer to your question, please let me know. -- Regards Michał Nowotka
Michal, Thanks for the response. I was able to locate the following post (http://www.nabble.com/Exposing-members-of-members-td21545250.html) and following sample code mentioned in the post (http://cci.lbl.gov/cctbx_sources/boost_adaptbx/) that were very helpful. In fact, exactly what I was looking for. Good luck. 2009/4/16 Michał Nowotka <mmmnow@gmail.com>:
I think I can partially answer your question. Although I don't know how to expose std::pair using indexing suite, thanks to Roman Yakovenko and his Py++ package, I can show you working example of exporting pair using different approach:
This is *.h file with class containing variable of type std::pair<int, int> to be exposed (this file is also available here: http://pygccxml.svn.sourceforge.net/viewvc/pygccxml?view=rev):
// Copyright 2004-2008 Roman Yakovenko. // Distributed under the Boost Software License, Version 1.0. (See // accompanying file LICENSE_1_0.txt or copy at // http://www.boost.org/LICENSE_1_0.txt)
#ifndef __std_pair_to_be_exported_hpp__ #define __std_pair_to_be_exported_hpp__
#include <utility>
struct tester_t{ tester_t(int a, int b){ pair_.first = a; pair_.second = b; }
int compute(){return pair_.first + pair_.second;}
std::pair<int, int> pair_; }; #endif//__std_pair_to_be_exported_hpp__
And here is wrapper code generated by Py++:
// This file has been generated by Py++.
// Copyright 2004-2008 Roman Yakovenko. // Distributed under the Boost Software License, Version 1.0. (See // accompanying file LICENSE_1_0.txt or copy at // http://www.boost.org/LICENSE_1_0.txt)
#include "boost/python.hpp"
#include "std_pair_to_be_exported.hpp"
namespace bp = boost::python;
BOOST_PYTHON_MODULE(std_pair){ bp::class_< std::pair< int, int > >( "pair_less__int_comma__int__greater_", "documentation", bp::init<
("documentation") ) .def( bp::init< int const &, int const & >(( bp::arg("__a"), bp::arg("__b") ), "documentation") ) .def_readwrite( "first", &std::pair< int, int >::first, "documentation" ) .def_readwrite( "second", &std::pair< int, int >::second, "documentation" );
bp::class_< tester_t >( "tester_t", "documentation", bp::init< int, int >(( bp::arg("a"), bp::arg("b") ), "documentation") ) .def( "compute" , (int ( ::tester_t::* )( ) )( &::tester_t::compute ) , "documentation" ) .def_readwrite( "pair_", &tester_t::pair_, "documentation" ); }
You should notice that in python: pairA = module.pair_less__int_comma__int__greater_(2,3) pairB = module.pair_less__int_comma__int__greater_(2,3) pairA.first == pairB.first
True
pairA.second == pairB.second
True
BUT:
pairA == pairB
False
I'm also interested in exposing std::pair using indexing suite because it perhaps make statement pairA == pairB become true. Especially if that code would be auto-generated by Py++ just like other STL containers it could be very useful. Roman Yakovenko wrote there is a chance this functionality would be added in next release of Py++.
Also you can ask this question on Cplusplus-sig mailing list: http://mail.python.org/mailman/listinfo/cplusplus-sig
If you find accurate answer to your question, please let me know.
-- Regards
Michał Nowotka _______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users
participants (2)
-
A B -
Michał Nowotka