ext-boost/boost/pointee.hpp
2014-12-07 23:50:51 +01:00

75 lines
1.7 KiB
C++

#ifndef POINTEE_DWA200415_HPP
# define POINTEE_DWA200415_HPP
//
// Copyright David Abrahams 2004. Use, modification and distribution is
// subject to the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
// typename pointee<P>::type provides the pointee type of P.
//
// For example, it is T for T* and X for shared_ptr<X>.
//
// http://www.boost.org/libs/iterator/doc/pointee.html
//
# include <boost/detail/is_incrementable.hpp>
# include <boost/iterator/iterator_traits.hpp>
# include <boost/type_traits/add_const.hpp>
# include <boost/type_traits/remove_cv.hpp>
# include <boost/mpl/if.hpp>
# include <boost/mpl/eval_if.hpp>
namespace boost {
namespace detail
{
template <class P>
struct smart_ptr_pointee
{
typedef typename P::element_type type;
};
template <class Iterator>
struct iterator_pointee
{
typedef typename iterator_traits<Iterator>::value_type value_type;
struct impl
{
template <class T>
static char test(T const&);
static char (& test(value_type&) )[2];
static Iterator& x;
};
BOOST_STATIC_CONSTANT(bool, is_constant = sizeof(impl::test(*impl::x)) == 1);
typedef typename mpl::if_c<
# if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x551))
::boost::detail::iterator_pointee<Iterator>::is_constant
# else
is_constant
# endif
, typename add_const<value_type>::type
, value_type
>::type type;
};
}
template <class P>
struct pointee
: mpl::eval_if<
detail::is_incrementable<P>
, detail::iterator_pointee<P>
, detail::smart_ptr_pointee<P>
>
{
};
} // namespace boost
#endif // POINTEE_DWA200415_HPP