/////////////////////////////////////////////////////////////////////////////// | |
/// \file utility.hpp | |
/// Proto callables for things found in the std \<utility\> header | |
// | |
// Copyright 2010 Eric Niebler. 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_PROTO_FUNCTIONAL_STD_UTILITY_HPP_EAN_11_27_2010 | |
#define BOOST_PROTO_FUNCTIONAL_STD_UTILITY_HPP_EAN_11_27_2010 | |
#include <utility> | |
#include <boost/type_traits/remove_const.hpp> | |
#include <boost/type_traits/remove_reference.hpp> | |
#include <boost/proto/proto_fwd.hpp> | |
namespace boost { namespace proto { namespace functional | |
{ | |
/// \brief A PolymorphicFunctionObject type that invokes the | |
/// \c std::make_pair() algorithm on its arguments. | |
/// | |
/// A PolymorphicFunctionObject type that invokes the | |
/// \c std::make_pair() algorithm on its arguments. | |
struct make_pair | |
{ | |
BOOST_PROTO_CALLABLE() | |
template<typename Sig> | |
struct result; | |
template<typename This, typename First, typename Second> | |
struct result<This(First, Second)> | |
{ | |
typedef | |
std::pair< | |
typename remove_const<typename remove_reference<First>::type>::type | |
, typename remove_const<typename remove_reference<Second>::type>::type | |
> | |
type; | |
}; | |
template<typename First, typename Second> | |
std::pair<First, Second> operator()(First const &first, Second const &second) const | |
{ | |
return std::make_pair(first, second); | |
} | |
}; | |
/// \brief A PolymorphicFunctionObject type that returns | |
/// the first element of a std::pair. | |
/// | |
/// A PolymorphicFunctionObject type that returns | |
/// the first element of a std::pair.. | |
struct first | |
{ | |
BOOST_PROTO_CALLABLE() | |
template<typename Sig> | |
struct result; | |
template<typename This, typename Pair> | |
struct result<This(Pair)> | |
{ | |
typedef typename Pair::first_type type; | |
}; | |
template<typename This, typename Pair> | |
struct result<This(Pair &)> | |
{ | |
typedef typename Pair::first_type &type; | |
}; | |
template<typename This, typename Pair> | |
struct result<This(Pair const &)> | |
{ | |
typedef typename Pair::first_type const &type; | |
}; | |
template<typename Pair> | |
typename Pair::first_type &operator()(Pair &pair) const | |
{ | |
return pair.first; | |
} | |
template<typename Pair> | |
typename Pair::first_type const &operator()(Pair const &pair) const | |
{ | |
return pair.first; | |
} | |
}; | |
/// \brief A PolymorphicFunctionObject type that returns | |
/// the second element of a std::pair. | |
/// | |
/// A PolymorphicFunctionObject type that returns | |
/// the second element of a std::pair.. | |
struct second | |
{ | |
BOOST_PROTO_CALLABLE() | |
template<typename Sig> | |
struct result; | |
template<typename This, typename Pair> | |
struct result<This(Pair)> | |
{ | |
typedef typename Pair::second_type type; | |
}; | |
template<typename This, typename Pair> | |
struct result<This(Pair &)> | |
{ | |
typedef typename Pair::second_type &type; | |
}; | |
template<typename This, typename Pair> | |
struct result<This(Pair const &)> | |
{ | |
typedef typename Pair::second_type const &type; | |
}; | |
template<typename Pair> | |
typename Pair::second_type &operator()(Pair &pair) const | |
{ | |
return pair.second; | |
} | |
template<typename Pair> | |
typename Pair::second_type const &operator()(Pair const &pair) const | |
{ | |
return pair.second; | |
} | |
}; | |
}}} | |
#endif |