Sprout/sprout/math/frac_int.hpp
2016-02-25 18:48:28 +09:00

60 lines
2.1 KiB
C++

/*=============================================================================
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_MATH_FRAC_INT_HPP
#define SPROUT_MATH_FRAC_INT_HPP
#include <type_traits>
#include <sprout/config.hpp>
#include <sprout/limits.hpp>
#include <sprout/math/detail/config.hpp>
#include <sprout/math/copysign.hpp>
#include <sprout/math/isnan.hpp>
#include <sprout/math/integer_part.hpp>
#include <sprout/type_traits/enabler_if.hpp>
#include <sprout/utility/pair/pair.hpp>
namespace sprout {
namespace math {
namespace detail {
template<typename T>
inline SPROUT_CONSTEXPR sprout::pair<T, T>
frac_int_impl(T x, T ipart) {
typedef sprout::pair<T, T> type;
return sprout::math::isnan(x) ? type(x, ipart)
: x == sprout::numeric_limits<T>::infinity() || x == -sprout::numeric_limits<T>::infinity() ? type(sprout::math::copysign(T(0), x), ipart)
: x == 0 ? type(x, ipart)
: x == ipart ? type(T(0) * x, ipart)
: type(sprout::math::copysign(x - ipart, x), ipart)
;
}
} // namespace detail
//
// frac_int
//
template<
typename FloatType,
typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
>
inline SPROUT_CONSTEXPR sprout::pair<FloatType, FloatType>
frac_int(FloatType x) {
return sprout::math::detail::frac_int_impl(x, sprout::integer_part(x));
}
template<
typename IntType,
typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
>
inline SPROUT_CONSTEXPR sprout::pair<double, double>
frac_int(IntType x) {
return sprout::math::frac_int(static_cast<double>(x));
}
} // namespace math
using sprout::math::frac_int;
} // namespace sprout
#endif // #ifndef SPROUT_MATH_FRAC_INT_HPP