boost::python and automatic conversion for const std::string&

[gabriel.becedillas at gmail.com]

I have a lot of functions returning "const std::string&". Every time I
wrap one of those I have to do it like this:

class_.def("name", &someclass::bla,
boost::python::return_value_policy<boost::python::copy_const_reference>()
);

Is there a way to register a return value conversion for "const
std::string&" so I can omit it every time I have to wrap functions
returning "const std::string&" ? I wan't those strings to be copied to
python as new strings (I don't want to hold a pointer to them).
Thanks