From 8dadcb359a3849682f42ea4cc807dbfc7ab911ea Mon Sep 17 00:00:00 2001
From: bolero-MURAKAMI <bolero.murakami@gmail.com>
Date: Sat, 5 May 2012 00:24:10 +0900
Subject: [PATCH] add sprout::asinh, acosh, atanh

---
 sprout/math/acosh.hpp      | 48 +++++++++++++++++++++++++++++++++++++
 sprout/math/asinh.hpp      | 46 +++++++++++++++++++++++++++++++++++
 sprout/math/atanh.hpp      | 49 ++++++++++++++++++++++++++++++++++++++
 sprout/math/hyperbolic.hpp |  3 +++
 4 files changed, 146 insertions(+)
 create mode 100644 sprout/math/acosh.hpp
 create mode 100644 sprout/math/asinh.hpp
 create mode 100644 sprout/math/atanh.hpp

diff --git a/sprout/math/acosh.hpp b/sprout/math/acosh.hpp
new file mode 100644
index 00000000..d8a750a9
--- /dev/null
+++ b/sprout/math/acosh.hpp
@@ -0,0 +1,48 @@
+#ifndef SPROUT_MATH_ACOSH_HPP
+#define SPROUT_MATH_ACOSH_HPP
+
+#include <limits>
+#include <type_traits>
+#include <sprout/config.hpp>
+#include <sprout/math/log.hpp>
+#include <sprout/math/sqrt.hpp>
+#include <sprout/utility/enabler_if.hpp>
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+#	include <cmath>
+#endif
+
+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 FloatType
+			acosh(FloatType x) {
+				return x < 1 ? std::numeric_limits<FloatType>::quiet_NaN()
+					: sprout::math::detail::log(x + sprout::math::detail::sqrt(x * x - 1))
+					;
+			}
+
+			template<
+				typename IntType,
+				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+			>
+			inline SPROUT_CONSTEXPR double
+			acosh(IntType x) {
+				return sprout::math::detail::acosh(static_cast<double>(x));
+			}
+		}	// namespace detail
+
+#	if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+		using std::acosh;
+#	else
+		using sprout::math::detail::acosh;
+#	endif
+	}	// namespace math
+
+	using sprout::math::acosh;
+}	// namespace sprout
+
+#endif	// #ifndef SPROUT_MATH_ACOSH_HPP
diff --git a/sprout/math/asinh.hpp b/sprout/math/asinh.hpp
new file mode 100644
index 00000000..ef0fc6bd
--- /dev/null
+++ b/sprout/math/asinh.hpp
@@ -0,0 +1,46 @@
+#ifndef SPROUT_MATH_ASINH_HPP
+#define SPROUT_MATH_ASINH_HPP
+
+#include <type_traits>
+#include <sprout/config.hpp>
+#include <sprout/math/log.hpp>
+#include <sprout/math/sqrt.hpp>
+#include <sprout/utility/enabler_if.hpp>
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+#	include <cmath>
+#endif
+
+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 FloatType
+			asinh(FloatType x) {
+				return sprout::math::detail::log(x + sprout::math::detail::sqrt(x * x + 1))
+					;
+			}
+
+			template<
+				typename IntType,
+				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+			>
+			inline SPROUT_CONSTEXPR double
+			asinh(IntType x) {
+				return sprout::math::detail::asinh(static_cast<double>(x));
+			}
+		}	// namespace detail
+
+#	if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+		using std::asinh;
+#	else
+		using sprout::math::detail::asinh;
+#	endif
+	}	// namespace math
+
+	using sprout::math::asinh;
+}	// namespace sprout
+
+#endif	// #ifndef SPROUT_MATH_ASINH_HPP
diff --git a/sprout/math/atanh.hpp b/sprout/math/atanh.hpp
new file mode 100644
index 00000000..1cc722fc
--- /dev/null
+++ b/sprout/math/atanh.hpp
@@ -0,0 +1,49 @@
+#ifndef SPROUT_MATH_ATANH_HPP
+#define SPROUT_MATH_ATANH_HPP
+
+#include <limits>
+#include <type_traits>
+#include <sprout/config.hpp>
+#include <sprout/math/log.hpp>
+#include <sprout/utility/enabler_if.hpp>
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+#	include <cmath>
+#endif
+
+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 FloatType
+			atanh(FloatType x) {
+				return x < -1 || x > 1 ? std::numeric_limits<FloatType>::quiet_NaN()
+					: x == -1 ? -std::numeric_limits<FloatType>::infinity()
+					: x == 1 ? std::numeric_limits<FloatType>::infinity()
+					: sprout::math::detail::log((1 + x) / (1 - x)) / 2
+					;
+			}
+
+			template<
+				typename IntType,
+				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+			>
+			inline SPROUT_CONSTEXPR double
+			atanh(IntType x) {
+				return sprout::math::detail::atanh(static_cast<double>(x));
+			}
+		}	// namespace detail
+
+#	if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+		using std::atanh;
+#	else
+		using sprout::math::detail::atanh;
+#	endif
+	}	// namespace math
+
+	using sprout::math::atanh;
+}	// namespace sprout
+
+#endif	// #ifndef SPROUT_MATH_ATANH_HPP
diff --git a/sprout/math/hyperbolic.hpp b/sprout/math/hyperbolic.hpp
index 32ae4216..731ea42e 100644
--- a/sprout/math/hyperbolic.hpp
+++ b/sprout/math/hyperbolic.hpp
@@ -4,5 +4,8 @@
 #include <sprout/math/sinh.hpp>
 #include <sprout/math/cosh.hpp>
 #include <sprout/math/tanh.hpp>
+#include <sprout/math/asinh.hpp>
+#include <sprout/math/acosh.hpp>
+#include <sprout/math/atanh.hpp>
 
 #endif	// #ifndef SPROUT_MATH_HYPERBOLIC_HPP