[C++-sig] non const std::string* as argument

[Max Ivanov]

>> std::string&    wrap_SerializeToString(const gp::Message& msg) {
>>        std::string tmp;
>>        msg.SerializeToString(&tmp);
>>        return tmp;
>> };
>
> Just remove reference from return type and you should be fine.
I've remove reference and bp::return_value_policy... from .def and
everything goes fine now, thanks again.

>> Message class is base class for Link which I
>> try to export to python, but Link never overrides SerializeToString.
>
> What?
I've Link class which I tried to export to Python Initially, which is
subclass of Message.

> Take a look on Py++ "Function Transformation" feature:
> http://language-binding.net/pyplusplus/documentation/functions/transformation/transformation.html
>
> It deals with such "wrappers".

Lot's of nice docs there, nice.