[section boost/python/pointee.hpp]

[section Introduction]

<boost/python/pointee.hpp> introduces a traits metafunction `template pointee<T>` that can be used to extract the "pointed-to" type from the type of a pointer or smart pointer.

[endsect]

[section Class template `pointee`]

`pointee<T>` is used by the [link high_level_components.boost_python_class_hpp.class_template_class_t_bases_hel `class_<...>`] template to deduce the type being held when a pointer or smart pointer type is used as its HeldType argument.

``

namespace boost { namespace python

{

template <class T> struct pointee

{

typedef T::element_type type;

};

// specialization for pointers

template <T> struct pointee<T*>

{

typedef T type;

};

}

``

[endsect]

[section Examples]

Given a 3rd-party smart pointer type `smart_pointer<T>`, one might partially specialize `pointee<smart_pointer<T> >` so that it can be used as the HeldType for a class wrapper:

``

#include <boost/python/pointee.hpp>

#include <boost/python/class.hpp>

#include <third_party_lib.hpp>

namespace boost { namespace python

{

template <class T> struct pointee<smart_pointer<T> >

{

typedef T type;

};

}}

BOOST_PYTHON_MODULE(pointee_demo)

{

class_<third_party_class, smart_pointer<third_party_class> >("third_party_class")

.def(...)

...

;

}

``

[endsect]

[endsect]