python/detail/unwrap_wrapper.hpp

0001 // Copyright David Abrahams 2004. Distributed under the Boost
0002 // Software License, Version 1.0. (See accompanying
0003 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0004 #ifndef UNWRAP_WRAPPER_DWA2004723_HPP
0005 # define UNWRAP_WRAPPER_DWA2004723_HPP
0006
0007 # include <boost/python/detail/prefix.hpp>
0008 # include <boost/python/detail/is_wrapper.hpp>
0009 # include <boost/mpl/eval_if.hpp>
0010 # include <boost/mpl/identity.hpp>
0011
0012 namespace boost { namespace python { namespace detail {
0013
0014 template <class T>
0015 struct unwrap_wrapper_helper
0016 {
0017     typedef typename T::_wrapper_wrapped_type_ type;
0018 };
0019
0020 template <class T>
0021 struct unwrap_wrapper_
0022   : mpl::eval_if<is_wrapper<T>,unwrap_wrapper_helper<T>,mpl::identity<T> >
0023 {};
0024
0025 template <class T>
0026 typename unwrap_wrapper_<T>::type*
0027 unwrap_wrapper(T*)
0028 {
0029     return 0;
0030 }
0031
0032 }}} // namespace boost::python::detail
0033
0034 #endif // UNWRAP_WRAPPER_DWA2004723_HPP