Sprout/sprout/functional/less.hpp
2012-10-25 12:50:03 +09:00

37 lines
925 B
C++

#ifndef SPROUT_FUNCTIONAL_LESS_HPP
#define SPROUT_FUNCTIONAL_LESS_HPP
#include <utility>
#include <sprout/config.hpp>
#include <sprout/utility/forward.hpp>
namespace sprout {
// Copyright (C) 2011 RiSK (sscrisk)
// 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:
template<typename T, typename U>
SPROUT_CONSTEXPR decltype(std::declval<T>() < std::declval<U>())
operator()(T&& x, U&& y)
const SPROUT_NOEXCEPT_EXPR(SPROUT_NOEXCEPT_EXPR(std::declval<T>() < std::declval<U>()))
{
return sprout::forward<T>(x) < sprout::forward<U>(y);
}
};
} // namespace sprout
#endif // #ifndef SPROUT_FUNCTIONAL_LESS_HPP