/* Copyright 2006-2009 Joaquin M Lopez Munoz.
|
* 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)
|
*
|
* See http://www.boost.org/libs/flyweight for library home page.
|
*/
|
|
#ifndef BOOST_FLYWEIGHT_DETAIL_IS_PLACEHOLDER_EXPR_HPP
|
#define BOOST_FLYWEIGHT_DETAIL_IS_PLACEHOLDER_EXPR_HPP
|
|
#if defined(_MSC_VER)
|
#pragma once
|
#endif
|
|
#include <boost/type_traits/is_same.hpp>
|
#include <boost/mpl/apply.hpp>
|
#include <boost/mpl/aux_/lambda_support.hpp>
|
#include <boost/mpl/not.hpp>
|
#include <boost/preprocessor/facilities/intercept.hpp>
|
#include <boost/preprocessor/repetition/enum_params.hpp>
|
|
namespace boost{
|
|
namespace flyweights{
|
|
namespace detail{
|
|
/* is_placeholder_expression<T> indicates whether T is an
|
* MPL placeholder expression.
|
*/
|
|
template<typename T>
|
struct is_placeholder_expression_helper
|
{
|
template<
|
BOOST_PP_ENUM_PARAMS(
|
BOOST_MPL_LIMIT_METAFUNCTION_ARITY,typename BOOST_PP_INTERCEPT)
|
>
|
struct apply{
|
typedef int type;
|
};
|
|
BOOST_MPL_AUX_LAMBDA_SUPPORT(1,is_placeholder_expression_helper,(T))
|
};
|
|
template<typename T>
|
struct is_placeholder_expression:
|
mpl::not_<is_same<
|
typename mpl::apply<
|
is_placeholder_expression_helper<T>,
|
BOOST_PP_ENUM_PARAMS(
|
BOOST_MPL_LIMIT_METAFUNCTION_ARITY,int BOOST_PP_INTERCEPT)
|
>::type,
|
int
|
> >
|
{};
|
|
} /* namespace flyweights::detail */
|
|
} /* namespace flyweights */
|
|
} /* namespace boost */
|
|
#endif
|
