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137 lines
3.8 KiB
137 lines
3.8 KiB
/////////////////////////////////////////////////////////////////////////////// |
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/// \file utility.hpp |
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/// Proto callables for things found in the std \<utility\> header |
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// |
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// Copyright 2010 Eric Niebler. Distributed under the Boost |
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// Software License, Version 1.0. (See accompanying file |
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// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) |
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#ifndef BOOST_PROTO_FUNCTIONAL_STD_UTILITY_HPP_EAN_11_27_2010 |
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#define BOOST_PROTO_FUNCTIONAL_STD_UTILITY_HPP_EAN_11_27_2010 |
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#include <utility> |
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#include <boost/type_traits/remove_const.hpp> |
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#include <boost/type_traits/remove_reference.hpp> |
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#include <boost/proto/proto_fwd.hpp> |
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namespace boost { namespace proto { namespace functional |
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{ |
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/// \brief A PolymorphicFunctionObject type that invokes the |
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/// \c std::make_pair() algorithm on its arguments. |
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/// |
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/// A PolymorphicFunctionObject type that invokes the |
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/// \c std::make_pair() algorithm on its arguments. |
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struct make_pair |
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{ |
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BOOST_PROTO_CALLABLE() |
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template<typename Sig> |
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struct result; |
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template<typename This, typename First, typename Second> |
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struct result<This(First, Second)> |
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{ |
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typedef |
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std::pair< |
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typename remove_const<typename remove_reference<First>::type>::type |
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, typename remove_const<typename remove_reference<Second>::type>::type |
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> |
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type; |
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}; |
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template<typename First, typename Second> |
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std::pair<First, Second> operator()(First const &first, Second const &second) const |
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{ |
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return std::make_pair(first, second); |
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} |
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}; |
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/// \brief A PolymorphicFunctionObject type that returns |
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/// the first element of a std::pair. |
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/// |
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/// A PolymorphicFunctionObject type that returns |
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/// the first element of a std::pair.. |
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struct first |
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{ |
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BOOST_PROTO_CALLABLE() |
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template<typename Sig> |
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struct result; |
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template<typename This, typename Pair> |
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struct result<This(Pair)> |
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{ |
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typedef typename Pair::first_type type; |
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}; |
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template<typename This, typename Pair> |
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struct result<This(Pair &)> |
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{ |
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typedef typename Pair::first_type &type; |
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}; |
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template<typename This, typename Pair> |
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struct result<This(Pair const &)> |
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{ |
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typedef typename Pair::first_type const &type; |
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}; |
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template<typename Pair> |
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typename Pair::first_type &operator()(Pair &pair) const |
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{ |
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return pair.first; |
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} |
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template<typename Pair> |
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typename Pair::first_type const &operator()(Pair const &pair) const |
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{ |
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return pair.first; |
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} |
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}; |
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/// \brief A PolymorphicFunctionObject type that returns |
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/// the second element of a std::pair. |
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/// |
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/// A PolymorphicFunctionObject type that returns |
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/// the second element of a std::pair.. |
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struct second |
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{ |
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BOOST_PROTO_CALLABLE() |
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template<typename Sig> |
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struct result; |
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template<typename This, typename Pair> |
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struct result<This(Pair)> |
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{ |
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typedef typename Pair::second_type type; |
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}; |
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template<typename This, typename Pair> |
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struct result<This(Pair &)> |
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{ |
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typedef typename Pair::second_type &type; |
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}; |
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template<typename This, typename Pair> |
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struct result<This(Pair const &)> |
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{ |
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typedef typename Pair::second_type const &type; |
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}; |
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template<typename Pair> |
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typename Pair::second_type &operator()(Pair &pair) const |
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{ |
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return pair.second; |
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} |
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template<typename Pair> |
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typename Pair::second_type const &operator()(Pair const &pair) const |
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{ |
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return pair.second; |
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} |
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}; |
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}}} |
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#endif
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