Warning C4267 in vector_indexing_suite.hpp and indexing_suite_detail.hpp

Commencez par boost/python/suite/indexing/vector_indexing_suite.hpp et boost/python/suite/indexing/detail/indexing_suite_detail.hpp aux emplacements des avertissements signalés. Compilez l’exemple vector_indexing_suite fourni avec Visual Studio 2017 et examinez l’arithmétique d’index concernée. Le travail est terminé lorsque l’exemple se compile sans avertissements C4267 tout en préservant le comportement de l’indexation.

Usage of boost::python::vector_indexing_suite leads to a warning :
boost/python/suite/indexing/detail/indexing_suite_detail.hpp(619): warning C4267: '+=': conversion from 'size_t' to 'long', possible loss of data

Here's a snippet of code that produces the warning.

#pragma warning(push)
#pragma warning(disable:4244)
// See https://svn.boost.org/trac10/ticket/3353 for 4244
#include <boost/python/suite/indexing/vector_indexing_suite.hpp>
#pragma warning(pop)

void test()
{
    boost::python::class_<std::vector<double>>("DoubleVec")
        .def(boost::python::vector_indexing_suite<std::vector<double> >())
        ;
}

Here's the output of VS2017:

1>test.cpp
1>C:\ThirdParty\1.8.0\win64-vc14\boost\include\boost-1_63\boost/python/suite/indexing/vector_indexing_suite.hpp(176): warning C4267: '+=': conversion from 'size_t' to 'long', possible loss of data
1>C:\ThirdParty\1.8.0\win64-vc14\boost\include\boost-1_63\boost/python/suite/indexing/vector_indexing_suite.hpp(170): note: while compiling class template member function 'unsigned __int64 boost::python::vector_indexing_suite<std::vector<double,std::allocator<_Ty>>,false,boost::python::detail::final_vector_derived_policies<Container,false>>::convert_index(Container &,PyObject *)'
1>        with
1>        [
1>            _Ty=double,
1>            Container=std::vector<double,std::allocator<double>>
1>        ]
1>C:\ThirdParty\1.8.0\win64-vc14\boost\include\boost-1_63\boost/python/suite/indexing/indexing_suite.hpp(261): note: see reference to function template instantiation 'unsigned __int64 boost::python::vector_indexing_suite<std::vector<double,std::allocator<_Ty>>,false,boost::python::detail::final_vector_derived_policies<Container,false>>::convert_index(Container &,PyObject *)' being compiled
1>        with
1>        [
1>            _Ty=double,
1>            Container=std::vector<double,std::allocator<double>>
1>        ]
1>C:\Users\Cyril\dev\test.cpp(9): note: see reference to class template instantiation 'boost::python::vector_indexing_suite<std::vector<double,std::allocator<_Ty>>,false,boost::python::detail::final_vector_derived_policies<Container,false>>' being compiled
1>        with
1>        [
1>            _Ty=double,
1>            Container=std::vector<double,std::allocator<double>>
1>        ]
1>C:\ThirdParty\1.8.0\win64-vc14\boost\include\boost-1_63\boost/bind/placeholders.hpp(54): note: see reference to class template instantiation 'boost::arg<9>' being compiled
1>C:\ThirdParty\1.8.0\win64-vc14\boost\include\boost-1_63\boost/bind/placeholders.hpp(53): note: see reference to class template instantiation 'boost::arg<8>' being compiled
1>C:\ThirdParty\1.8.0\win64-vc14\boost\include\boost-1_63\boost/bind/placeholders.hpp(52): note: see reference to class template instantiation 'boost::arg<7>' being compiled
1>C:\ThirdParty\1.8.0\win64-vc14\boost\include\boost-1_63\boost/bind/placeholders.hpp(51): note: see reference to class template instantiation 'boost::arg<6>' being compiled
1>C:\ThirdParty\1.8.0\win64-vc14\boost\include\boost-1_63\boost/bind/placeholders.hpp(50): note: see reference to class template instantiation 'boost::arg<5>' being compiled
1>C:\ThirdParty\1.8.0\win64-vc14\boost\include\boost-1_63\boost/bind/placeholders.hpp(49): note: see reference to class template instantiation 'boost::arg<4>' being compiled
1>C:\ThirdParty\1.8.0\win64-vc14\boost\include\boost-1_63\boost/bind/placeholders.hpp(48): note: see reference to class template instantiation 'boost::arg<3>' being compiled
1>C:\ThirdParty\1.8.0\win64-vc14\boost\include\boost-1_63\boost/bind/placeholders.hpp(47): note: see reference to class template instantiation 'boost::arg<2>' being compiled
1>C:\ThirdParty\1.8.0\win64-vc14\boost\include\boost-1_63\boost/bind/placeholders.hpp(46): note: see reference to class template instantiation 'boost::arg<1>' being compiled
1>C:\ThirdParty\1.8.0\win64-vc14\boost\include\boost-1_63\boost/python/suite/indexing/detail/indexing_suite_detail.hpp(605): warning C4267: '+=': conversion from 'size_t' to 'long', possible loss of data
1>C:\ThirdParty\1.8.0\win64-vc14\boost\include\boost-1_63\boost/python/suite/indexing/detail/indexing_suite_detail.hpp(590): note: while compiling class template member function 'void boost::python::detail::slice_helper<Container,DerivedPolicies,boost::python::detail::no_proxy_helper<Container,DerivedPolicies,boost::python::detail::container_element<Container,Index,DerivedPolicies>,Index>,Data,Index>::base_get_slice_data(Container &,PySliceObject *,Index &,Index &)'
1>        with
1>        [
1>            Container=std::vector<double,std::allocator<double>>,
1>            DerivedPolicies=boost::python::detail::final_vector_derived_policies<std::vector<double,std::allocator<double>>,false>,
1>            Index=unsigned __int64,
1>            Data=double
1>        ]
1>C:\ThirdParty\1.8.0\win64-vc14\boost\include\boost-1_63\boost/python/suite/indexing/detail/indexing_suite_detail.hpp(695): note: see reference to function template instantiation 'void boost::python::detail::slice_helper<Container,DerivedPolicies,boost::python::detail::no_proxy_helper<Container,DerivedPolicies,boost::python::detail::container_element<Container,Index,DerivedPolicies>,Index>,Data,Index>::base_get_slice_data(Container &,PySliceObject *,Index &,Index &)' being compiled
1>        with
1>        [
1>            Container=std::vector<double,std::allocator<double>>,
1>            DerivedPolicies=boost::python::detail::final_vector_derived_policies<std::vector<double,std::allocator<double>>,false>,
1>            Index=unsigned __int64,
1>            Data=double
1>        ]
1>C:\ThirdParty\1.8.0\win64-vc14\boost\include\boost-1_63\boost/python/suite/indexing/indexing_suite.hpp(256): note: see reference to class template instantiation 'boost::python::detail::slice_helper<Container,DerivedPolicies,boost::python::detail::no_proxy_helper<Container,DerivedPolicies,boost::python::detail::container_element<Container,Index,DerivedPolicies>,Index>,Data,Index>' being compiled
1>        with
1>        [
1>            Container=std::vector<double,std::allocator<double>>,
1>            DerivedPolicies=boost::python::detail::final_vector_derived_policies<std::vector<double,std::allocator<double>>,false>,
1>            Index=unsigned __int64,
1>            Data=double
1>        ]
1>C:\ThirdParty\1.8.0\win64-vc14\boost\include\boost-1_63\boost/python/suite/indexing/indexing_suite.hpp(253): note: while compiling class template member function 'void boost::python::indexing_suite<Container,DerivedPolicies,false,false,double,unsigned __int64,double>::base_delete_item(Container &,PyObject *)'
1>        with
1>        [
1>            Container=std::vector<double,std::allocator<double>>,
1>            DerivedPolicies=boost::python::detail::final_vector_derived_policies<std::vector<double,std::allocator<double>>,false>
1>        ]
1>C:\ThirdParty\1.8.0\win64-vc14\boost\include\boost-1_63\boost/python/suite/indexing/indexing_suite.hpp(186): note: see reference to function template instantiation 'void boost::python::indexing_suite<Container,DerivedPolicies,false,false,double,unsigned __int64,double>::base_delete_item(Container &,PyObject *)' being compiled
1>        with
1>        [
1>            Container=std::vector<double,std::allocator<double>>,
1>            DerivedPolicies=boost::python::detail::final_vector_derived_policies<std::vector<double,std::allocator<double>>,false>
1>        ]
1>C:\ThirdParty\1.8.0\win64-vc14\boost\include\boost-1_63\boost/python/suite/indexing/vector_indexing_suite.hpp(50): note: see reference to class template instantiation 'boost::python::indexing_suite<Container,DerivedPolicies,false,false,double,unsigned __int64,double>' being compiled
1>        with
1>        [
1>            Container=std::vector<double,std::allocator<double>>,
1>            DerivedPolicies=boost::python::detail::final_vector_derived_policies<std::vector<double,std::allocator<double>>,false>
1>        ]
1>C:\ThirdParty\1.8.0\win64-vc14\boost\include\boost-1_63\boost/python/suite/indexing/detail/indexing_suite_detail.hpp(619): warning C4267: '+=': conversion from 'size_t' to 'long', possible loss of data

I'm using Boost 1.63, VisualStudio 2017 15.5.4.