// Copyright Daniel Wallin, David Abrahams 2010.
|
// Distributed under 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)
|
|
#ifndef BOOST_PARAMETER_IS_MAYBE_050329_HPP
|
#define BOOST_PARAMETER_IS_MAYBE_050329_HPP
|
|
namespace boost { namespace parameter { namespace aux {
|
|
struct maybe_base
|
{
|
};
|
}}} // namespace boost::parameter::aux
|
|
#if defined(BOOST_PARAMETER_CAN_USE_MP11)
|
#include <type_traits>
|
|
namespace boost { namespace parameter { namespace aux {
|
|
template <typename T>
|
using is_maybe = ::std::is_base_of<
|
::boost::parameter::aux::maybe_base
|
, typename ::std::remove_const<T>::type
|
>;
|
}}} // namespace boost::parameter::aux
|
|
#else // !defined(BOOST_PARAMETER_CAN_USE_MP11)
|
#include <boost/mpl/bool.hpp>
|
#include <boost/mpl/if.hpp>
|
#include <boost/type_traits/is_base_of.hpp>
|
#include <boost/type_traits/remove_const.hpp>
|
|
namespace boost { namespace parameter { namespace aux {
|
|
template <typename T>
|
struct is_maybe
|
: ::boost::mpl::if_<
|
::boost::is_base_of<
|
::boost::parameter::aux::maybe_base
|
, typename ::boost::remove_const<T>::type
|
>
|
, ::boost::mpl::true_
|
, ::boost::mpl::false_
|
>::type
|
{
|
};
|
}}} // namespace boost::parameter::aux
|
|
#endif // BOOST_PARAMETER_CAN_USE_MP11
|
#endif // include guard
|
