[C++-sig] make_constructor and BOOST_PYTHON_FUNCTION_OVERLOADS
talljimbo at gmail.com
Thu Feb 2 16:39:15 CET 2012
On 02/02/2012 09:30 AM, Holger Brandsmeier wrote:
> Dear list,
> how can I combine make_constructor() and BOOST_PYTHON_FUNCTION_OVERLOADS()?
> I have a static member function in a class that "acts like a
> constructors", in the sense that it returns a shared pointer to the
> class. The function has default arguments, thats why I was thinking of
> using BOOST_PYTHON_FUNCTION_OVERLOADS.
> For usual member functions I've been using it like this:
> BOOST_PYTHON_MEMBER_FUNCTION_OVERLOADS(Operator_apply, apply, 2, 5)
> .def("apply",&ClassT::apply, Operator_apply() )
> So for the constructor I thought probably I should use it like
> BOOST_PYTHON_FUNCTION_OVERLOADS(fPfemSpace_create, create, 2, 3)
> .def("__init__", make_constructor(&ClassT::create ),
> but that fails with the error:
> /usr/include/boost/python/class.hpp:598:37: error: no matching
> function for call to 'get_signature'
> name, overloads, *this, detail::get_signature(sig));
> I tried out a few other variations for ".def(" but I didn't find the
> right one yet. Is there a way to combine make_constructor with
I've always used arg lists rather than the OVERLOADS macros to deal with
default arguments, and I can confirm that those work with make_constructor:
The advantage is that your Python users get to use keyword args; the
disadvantage is that you have to write them out (along with the default
I have noticed, however, that make_constructor isn't as flexible as
make_function about the order of its own optional arguments - if you
want to pass args, you also have to pass default_call_policies as the
second argument, as I did above. The same trick might work for the
OVERLOADS macros, if you'd prefer to use those.
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