iterator/include/boost/pointee.hpp
2025-01-26 15:45:03 +03:00

61 lines
1.4 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/mpl/eval_if.hpp>
#include <iterator>
#include <type_traits>
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 std::iterator_traits<Iterator>::value_type value_type;
typedef typename std::conditional<
std::is_const<
typename std::remove_reference<decltype(*std::declval<Iterator&>())>::type
>::value
, typename std::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