Sprout/sprout/math/float2_exponent.hpp
2013-04-26 00:25:35 +09:00

44 lines
1.3 KiB
C++

#ifndef SPROUT_MATH_FLOAT2_EXPONENT_HPP
#define SPROUT_MATH_FLOAT2_EXPONENT_HPP
#include <climits>
#include <limits>
#include <type_traits>
#include <sprout/config.hpp>
#include <sprout/math/detail/config.hpp>
#include <sprout/math/ilogb2.hpp>
#include <sprout/math/isnan.hpp>
#include <sprout/type_traits/enabler_if.hpp>
namespace sprout {
namespace math {
namespace detail {
template<
typename FloatType,
typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
>
inline SPROUT_CONSTEXPR int
float2_exponent(FloatType x) {
return x == 0 ? 0
: x == std::numeric_limits<FloatType>::infinity() || x == -std::numeric_limits<FloatType>::infinity() ? 0
: sprout::math::isnan(x) ? FP_ILOGBNAN
: sprout::math::ilogb2(x) + 1
;
}
template<
typename IntType,
typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
>
inline SPROUT_CONSTEXPR int
float2_exponent(IntType x) {
return sprout::math::detail::float2_exponent(static_cast<double>(x));
}
} // namespace detail
using sprout::math::detail::float2_exponent;
} // namespace math
using sprout::math::float2_exponent;
} // namespace sprout
#endif // #ifndef SPROUT_MATH_FLOAT2_EXPONENT_HPP