Re: Boost/Python: method overloading w/out default args

From: David Abrahams (dave_at_[hidden])
Date: 2003-01-15 00:16:13

"Bruce Lowery <bruce_lowery_at_[hidden]>" <bruce_lowery_at_[hidden]> writes:

> <bruce_lowery_at_y...>" <bruce_lowery_at_y...> wrote:
>> 
>> Using Boost/Python, how does one overload methods?  For instance:
>> 
>> struct Bar
>> {
>>      void func( const std::string& s );
>>      void func( int i );
>> };
>> 
>> BOOST_PYTHON_MODULE( Foo )
>> {
>> class_<Bar>( "Bar" )
>>      .def( "func", &Bar::func )
>>      .def(  ??? )
>>      ;
>> }
>> 
>> The reference documentation discusses the 
>> BOOST_PYTHON_MEMBER_FUNCTION_OVERLOADS macro, but it only seems to 
>> apply to methods with default arguments.
>> 
>> --bruce
>
>
> I should have scanned the python c++ SIG first.  Also now realize 
> that python.boost questions are preferred on that list rather than 
> here.
>
> For future newbie reference, solution to above appears to be:
>
> struct Bar
> {
>      void func( const std::string& s );
>      void func( int i );
> };
>
>
> BOOST_PYTHON_MEMBER_FUNCTION_OVERLOADS( Bar_func_overloads, Bar::func, 1, 1 )
>
>
> BOOST_PYTHON_MODULE( Foo )
> {
>    class_<Bar>( "Bar" )
>      .def("func",(void(Bar::*)(const std::string&))0,Bar_func_overloads)
>      .def("func",(void(Bar::*)(int))0,Bar_func_overloads)
>      ;
> }

This is not really a good use of
BOOST_PYTHON_MEMBER_FUNCTION_OVERLOADS. You should leave it out and do
this instead:

 BOOST_PYTHON_MODULE( Foo )
 {
    class_<Bar>( "Bar" )
      .def("func"
           , static_cast<void(Bar::*)(const std::string&)>(&Bar::func))
      .def("func"
           , static_cast<void(Bar::*)(int)>(&Bar::func))
      ;
 }

-- 
                       David Abrahams
   dave_at_[hidden] * http://www.boost-consulting.com
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