/*============================================================================= Copyright (c) 2011-2015 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_TANH_HPP #define SPROUT_MATH_TANH_HPP #include #include #include #include #include #include #include #include namespace sprout { namespace math { namespace detail { #if SPROUT_USE_BUILTIN_CMATH_FUNCTION inline SPROUT_CONSTEXPR float builtin_tanh(float x) { return __builtin_tanhf(x); } inline SPROUT_CONSTEXPR double builtin_tanh(double x) { return __builtin_tanh(x); } inline SPROUT_CONSTEXPR long double builtin_tanh(long double x) { return __builtin_tanhl(x); } #endif template inline SPROUT_CONSTEXPR T tanh_impl_2(T t, T u) { return (t - u) / (t + u); } template inline SPROUT_CONSTEXPR T tanh_impl_1(T t) { return sprout::math::detail::tanh_impl_2(t, T(1) / t); } template inline SPROUT_CONSTEXPR T tanh_impl(T x) { return sprout::math::detail::tanh_impl_1(sprout::math::exp(x)); } } // namespace detail // // tanh // template< typename FloatType, typename sprout::enabler_if::value>::type = sprout::enabler > inline SPROUT_CONSTEXPR FloatType tanh(FloatType x) { return sprout::math::isnan(x) ? x : x == sprout::numeric_limits::infinity() ? FloatType(1) : x == -sprout::numeric_limits::infinity() ? FloatType(-1) #if SPROUT_USE_BUILTIN_CMATH_FUNCTION : sprout::math::detail::builtin_tanh(x) #else : x == 0 ? x : static_cast(sprout::math::detail::tanh_impl(static_cast::type>(x))) #endif ; } template< typename IntType, typename sprout::enabler_if::value>::type = sprout::enabler > inline SPROUT_CONSTEXPR double tanh(IntType x) { return sprout::math::tanh(static_cast(x)); } } // namespace math using sprout::math::tanh; } // namespace sprout #endif // #ifndef SPROUT_MATH_TANH_HPP