Sprout/sprout/math/float_exponent.hpp
2019-01-07 17:47:17 +09:00

49 lines
1.6 KiB
C++

/*=============================================================================
Copyright (c) 2011-2019 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_FLOAT_EXPONENT_HPP
#define SPROUT_MATH_FLOAT_EXPONENT_HPP
#include <type_traits>
#include <sprout/config.hpp>
#include <sprout/limits.hpp>
#include <sprout/math/detail/config.hpp>
#include <sprout/math/ilogb.hpp>
#include <sprout/math/isnan.hpp>
#include <sprout/type_traits/enabler_if.hpp>
namespace sprout {
namespace math {
//
// float_exponent
//
template<
typename FloatType,
typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
>
inline SPROUT_CONSTEXPR int
float_exponent(FloatType x) {
return sprout::math::isnan(x) ? 0
: x == 0 ? 0
: x == sprout::numeric_limits<FloatType>::infinity() || x == -sprout::numeric_limits<FloatType>::infinity() ? 0
: sprout::math::ilogb(x) + 1
;
}
template<
typename IntType,
typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
>
inline SPROUT_CONSTEXPR int
float_exponent(IntType x) {
return sprout::math::float_exponent(static_cast<double>(x));
}
} // namespace math
using sprout::math::float_exponent;
} // namespace sprout
#endif // #ifndef SPROUT_MATH_FLOAT_EXPONENT_HPP