[C++-sig] Strange Boost.Python-related compile error

[Lawrence Spector]

Sorry about that example.  I must've been in a daze when I posted that.  I copy and pasted from two different parts of code and tried to make the example more generic, but... uhh, anyway what I posted yesterday doesn't make any sense.

So, as you requested, here's a sample that demonstrates the problem.

// Very simple class to demonstrate issue:

#include <string>
#include <boost/variant.hpp>

typedef boost::variant<std::wstring> ReturnType;

class TestClass
{
public:
        virtual const ReturnType getValue() const;
}; // end Derived

// Generated Boost.Python code from Py++

#include "boost/python.hpp"

namespace bp = boost::python;

struct TestClass_wrapper : TestClass, bp::wrapper< TestClass > {

    TestClass_wrapper(TestClass const & arg )
    : TestClass( arg )
      , bp::wrapper< TestClass >(){
        // copy constructor

    }

    TestClass_wrapper()
    : TestClass()
      , bp::wrapper< TestClass >(){
        // null constructor

    }

    virtual ::ReturnType const getValue(  ) const  {
        if( bp::override func_getValue = this->get_override( "getValue" ) )
            return func_getValue(  ); // **** This is the error line
        else
            return this->TestClass::getValue(  );
    }


    ::ReturnType const default_getValue(  ) const  {
        return TestClass::getValue( );
    }

};

BOOST_PYTHON_MODULE(pyplusplus){
    bp::class_< TestClass_wrapper >( "TestClass" )
        .def(
            "getValue"
            , &::TestClass::getValue
            , &TestClass_wrapper::default_getValue );
}

Output:

1>------ Build started: Project: VariantCompileError, Configuration: Debug Win32 ------
1>Compiling...
1>BpErr.cpp
1>c:\3rdparty\boost_1_34_0\boost\python\detail\caller.hpp(52) : warning C4244: 'return' : conversion from 'Py_ssize_t' to 'unsigned int', possible loss of data
1>c:\3rdparty\boost_1_34_0\boost\variant\variant.hpp(1273) : error C2665: 'boost::detail::variant::make_initializer_node::apply<BaseIndexPair,Iterator>::initializer_node::initialize' : none of the 2 overloads could convert all the argument types
1>        with
1>        [
1>            BaseIndexPair=boost::mpl::pair<boost::detail::variant::initializer_root,boost::mpl::int_<0>>,
1>            Iterator=boost::mpl::l_iter<boost::mpl::list1<std::basic_string<wchar_t,std::char_traits<wchar_t>,std::allocator<wchar_t>>>>
1>        ]
1>        c:\3rdparty\boost_1_34_0\boost\variant\detail\initializer.hpp(89): could be 'int boost::detail::variant::make_initializer_node::apply<BaseIndexPair,Iterator>::initializer_node::initialize(void *,const std::basic_string<_Elem,_Traits,_Ax> &)'
1>        with
1>        [
1>            BaseIndexPair=boost::mpl::pair<boost::detail::variant::initializer_root,boost::mpl::int_<0>>,
1>            Iterator=boost::mpl::l_iter<boost::mpl::list1<std::basic_string<wchar_t,std::char_traits<wchar_t>,std::allocator<wchar_t>>>>,
1>            _Elem=wchar_t,
1>            _Traits=std::char_traits<wchar_t>,
1>            _Ax=std::allocator<wchar_t>
1>        ]
1>        while trying to match the argument list '(void *, const boost::python::detail::method_result)'
1>        c:\3rdparty\boost_1_34_0\boost\variant\variant.hpp(1342) : see reference to function template instantiation 'void boost::variant<T0_>::convert_construct<const T>(T &,int,boost::mpl::false_)' being compiled
1>        with
1>        [
1>            T0_=std::wstring,
1>            T=boost::python::detail::method_result
1>        ]
1>        c:\work\sandbox\boost\python\variantcompileerror\src\bperr.cpp(38) : see reference to function template instantiation 'boost::variant<T0_>::variant<boost::python::detail::method_result>(const T &)' being compiled
1>        with
1>        [
1>            T0_=std::wstring,
1>            T=boost::python::detail::method_result
1>        ]
1>Build log was saved at "file://c:\Work\Sandbox\Boost\Python\VariantCompileError\VariantCompileErrorVC80\Debug\BuildLog.htm"
1>VariantCompileError - 1 error(s), 1 warning(s)
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

Any ideas what's going on?

Thanks,

Lawrence