/*============================================================================= Copyright (c) 2011 RiSK (sscrisk) https://github.com/sscrisk/CEL---ConstExpr-Library Copyright (c) 2011-2016 Bolero MURAKAMI https://github.com/bolero-MURAKAMI/Sprout 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 SPROUT_FUNCTIONAL_LESS_HPP #define SPROUT_FUNCTIONAL_LESS_HPP #include <utility> #include <sprout/config.hpp> #include <sprout/utility/forward.hpp> #include <sprout/functional/transparent.hpp> namespace sprout { // 20.8.5 Comparisons template<typename T = void> struct less { public: typedef T first_argument_type; typedef T second_argument_type; typedef bool result_type; public: SPROUT_CONSTEXPR bool operator()(T const& x, T const& y) const { return x < y; } }; template<> struct less<void> : public sprout::transparent<> { public: template<typename T, typename U> SPROUT_CONSTEXPR decltype(std::declval<T>() < std::declval<U>()) operator()(T&& x, U&& y) const SPROUT_NOEXCEPT_IF_EXPR(std::declval<T>() < std::declval<U>()) { return SPROUT_FORWARD(T, x) < SPROUT_FORWARD(U, y); } }; } // namespace sprout #endif // #ifndef SPROUT_FUNCTIONAL_LESS_HPP