From 69590e2ad27340b89338223237185e9c1a48edbc Mon Sep 17 00:00:00 2001
From: Nick Matteo <kundor@kundor.org>
Date: Wed, 25 May 2016 11:37:03 -0400
Subject: [PATCH] Split complex and quaternion arithmetic and stream operators

---
 sprout/complex.hpp                            |   3 +-
 sprout/complex/arithmetic_operators.hpp       | 136 +++++
 sprout/complex/asin.hpp                       |   2 +-
 sprout/complex/atan.hpp                       |   2 +-
 sprout/complex/atanh.hpp                      |   2 +-
 sprout/complex/cosh.hpp                       |   2 +-
 sprout/complex/log10.hpp                      |   2 +-
 sprout/complex/log2.hpp                       |   2 +-
 sprout/complex/operators.hpp                  | 185 +-----
 sprout/complex/pow.hpp                        |   2 +-
 sprout/complex/sin.hpp                        |   2 +-
 sprout/complex/sinh.hpp                       |   2 +-
 sprout/complex/stream_operators.hpp           |  51 ++
 sprout/complex/tan.hpp                        |   2 +-
 sprout/complex/tanh.hpp                       |   2 +-
 sprout/math/quaternion.hpp                    |   3 +-
 .../math/quaternion/arithmetic_operators.hpp  | 381 ++++++++++++
 sprout/math/quaternion/norm.hpp               |   2 +-
 sprout/math/quaternion/operators.hpp          | 552 +-----------------
 sprout/math/quaternion/stream_operators.hpp   | 200 +++++++
 20 files changed, 801 insertions(+), 734 deletions(-)
 create mode 100644 sprout/complex/arithmetic_operators.hpp
 create mode 100644 sprout/complex/stream_operators.hpp
 create mode 100644 sprout/math/quaternion/arithmetic_operators.hpp
 create mode 100644 sprout/math/quaternion/stream_operators.hpp

diff --git a/sprout/complex.hpp b/sprout/complex.hpp
index b4567304..a6630d96 100644
--- a/sprout/complex.hpp
+++ b/sprout/complex.hpp
@@ -10,7 +10,8 @@
 
 #include <sprout/config.hpp>
 #include <sprout/complex/complex.hpp>
-#include <sprout/complex/operators.hpp>
+#include <sprout/complex/arithmetic_operators.hpp>
+#include <sprout/complex/stream_operators.hpp>
 #include <sprout/complex/values.hpp>
 #include <sprout/complex/transcendentals.hpp>
 #include <sprout/complex/hash.hpp>
diff --git a/sprout/complex/arithmetic_operators.hpp b/sprout/complex/arithmetic_operators.hpp
new file mode 100644
index 00000000..08acc52c
--- /dev/null
+++ b/sprout/complex/arithmetic_operators.hpp
@@ -0,0 +1,136 @@
+/*=============================================================================
+  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_COMPLEX_ARITHMETIC_OPERATORS_HPP
+#define SPROUT_COMPLEX_ARITHMETIC_OPERATORS_HPP
+
+#include <sprout/config.hpp>
+#include <sprout/complex/complex.hpp>
+
+namespace sprout {
+	// 26.4.6, operators:
+	template<typename T>
+	inline SPROUT_CONSTEXPR sprout::complex<T>
+	operator+(sprout::complex<T> const& lhs, sprout::complex<T> const& rhs) {
+		return sprout::complex<T>(lhs.real() + rhs.real(), lhs.imag() + rhs.imag());
+	}
+	template<typename T>
+	inline SPROUT_CONSTEXPR sprout::complex<T>
+	operator+(sprout::complex<T> const& lhs, T const& rhs) {
+		return sprout::complex<T>(lhs.real() + rhs, lhs.imag());
+	}
+	template<typename T>
+	inline SPROUT_CONSTEXPR sprout::complex<T>
+	operator+(T const& lhs, sprout::complex<T> const& rhs) {
+		return sprout::complex<T>(lhs + rhs.real(), rhs.imag());
+	}
+	template<typename T>
+	inline SPROUT_CONSTEXPR sprout::complex<T>
+	operator-(sprout::complex<T> const& lhs, sprout::complex<T> const& rhs) {
+		return sprout::complex<T>(lhs.real() - rhs.real(), lhs.imag() - rhs.imag());
+	}
+	template<typename T>
+	inline SPROUT_CONSTEXPR sprout::complex<T>
+	operator-(sprout::complex<T> const& lhs, T const& rhs) {
+		return sprout::complex<T>(lhs.real() - rhs, lhs.imag());
+	}
+	template<typename T>
+	inline SPROUT_CONSTEXPR sprout::complex<T>
+	operator-(T const& lhs, sprout::complex<T> const& rhs) {
+		return sprout::complex<T>(lhs - rhs.real(), -rhs.imag());
+	}
+	template<typename T>
+	inline SPROUT_CONSTEXPR sprout::complex<T>
+	operator*(sprout::complex<T> const& lhs, sprout::complex<T> const& rhs) {
+		return sprout::complex<T>(
+			lhs.real() * rhs.real() - lhs.imag() * rhs.imag(),
+			lhs.real() * rhs.imag() + lhs.imag() * rhs.real()
+			);
+	}
+	template<typename T>
+	inline SPROUT_CONSTEXPR sprout::complex<T>
+	operator*(sprout::complex<T> const& lhs, T const& rhs) {
+		return sprout::complex<T>(lhs.real() * rhs, lhs.imag() * rhs);
+	}
+	template<typename T>
+	inline SPROUT_CONSTEXPR sprout::complex<T>
+	operator*(T const& lhs, sprout::complex<T> const& rhs) {
+		return sprout::complex<T>(lhs * rhs.real(), lhs * rhs.imag());
+	}
+	namespace detail {
+		template<typename T>
+		inline SPROUT_CONSTEXPR sprout::complex<T>
+		divides_impl(sprout::complex<T> const& lhs, sprout::complex<T> const& rhs, T const& n) {
+			return sprout::complex<T>(
+				(lhs.real() * rhs.real() + lhs.imag() * rhs.imag()) / n,
+				(lhs.imag() * rhs.real() - lhs.real() * rhs.imag()) / n
+				);
+		}
+		template<typename T>
+		inline SPROUT_CONSTEXPR sprout::complex<T>
+		divides_impl(T const& lhs, sprout::complex<T> const& rhs, T const& n) {
+			return sprout::complex<T>(lhs * rhs.real() / n, -lhs * rhs.imag() / n);
+		}
+	}	// namespace detail
+	template<typename T>
+	inline SPROUT_CONSTEXPR sprout::complex<T>
+	operator/(sprout::complex<T> const& lhs, sprout::complex<T> const& rhs) {
+		return sprout::detail::divides_impl(lhs, rhs, sprout::detail::complex_norm(rhs));
+	}
+	template<typename T>
+	inline SPROUT_CONSTEXPR sprout::complex<T>
+	operator/(sprout::complex<T> const& lhs, T const& rhs) {
+		return sprout::complex<T>(lhs.real() / rhs, lhs.imag() / rhs);
+	}
+	template<typename T>
+	inline SPROUT_CONSTEXPR sprout::complex<T>
+	operator/(T const& lhs, sprout::complex<T> const& rhs) {
+		return sprout::detail::divides_impl(lhs, rhs, sprout::detail::complex_norm(rhs));
+	}
+	template<typename T>
+	inline SPROUT_CONSTEXPR sprout::complex<T>
+	operator+(sprout::complex<T> const& x) {
+		return x;
+	}
+	template<typename T>
+	inline SPROUT_CONSTEXPR sprout::complex<T>
+	operator-(sprout::complex<T> const& x) {
+		return sprout::complex<T>(-x.real(), -x.imag());
+	}
+	template<typename T>
+	inline SPROUT_CONSTEXPR bool
+	operator==(sprout::complex<T> const& lhs, sprout::complex<T> const& rhs) {
+		return lhs.real() == rhs.real() && lhs.imag() == rhs.imag();
+	}
+	template<typename T>
+	inline SPROUT_CONSTEXPR bool
+	operator==(sprout::complex<T> const& lhs, T const& rhs) {
+		return lhs.real() == rhs && lhs.imag() == T();
+	}
+	template<typename T>
+	inline SPROUT_CONSTEXPR bool
+	operator==(T const& lhs, sprout::complex<T> const& rhs) {
+		return lhs == rhs.real() && T() == rhs.imag();
+	}
+	template<typename T>
+	inline SPROUT_CONSTEXPR bool
+	operator!=(sprout::complex<T> const& lhs, sprout::complex<T> const& rhs) {
+		return !(lhs == rhs);
+	}
+	template<typename T>
+	inline SPROUT_CONSTEXPR bool
+	operator!=(sprout::complex<T> const& lhs, T const& rhs) {
+		return !(lhs == rhs);
+	}
+	template<typename T>
+	inline SPROUT_CONSTEXPR bool
+	operator!=(T const& lhs, sprout::complex<T> const& rhs) {
+		return !(lhs == rhs);
+	}
+}	// namespace sprout
+
+#endif	// #ifndef SPROUT_COMPLEX_ARITHMETIC_OPERATORS_HPP
diff --git a/sprout/complex/asin.hpp b/sprout/complex/asin.hpp
index ce2f7dfc..83beb68d 100644
--- a/sprout/complex/asin.hpp
+++ b/sprout/complex/asin.hpp
@@ -10,7 +10,7 @@
 
 #include <sprout/config.hpp>
 #include <sprout/complex/complex.hpp>
-#include <sprout/complex/operators.hpp>
+#include <sprout/complex/arithmetic_operators.hpp>
 #include <sprout/complex/perp.hpp>
 #include <sprout/complex/asinh.hpp>
 
diff --git a/sprout/complex/atan.hpp b/sprout/complex/atan.hpp
index f5ed6033..79505dcb 100644
--- a/sprout/complex/atan.hpp
+++ b/sprout/complex/atan.hpp
@@ -10,7 +10,7 @@
 
 #include <sprout/config.hpp>
 #include <sprout/complex/complex.hpp>
-#include <sprout/complex/operators.hpp>
+#include <sprout/complex/arithmetic_operators.hpp>
 #include <sprout/complex/perp.hpp>
 #include <sprout/complex/atanh.hpp>
 
diff --git a/sprout/complex/atanh.hpp b/sprout/complex/atanh.hpp
index c3931883..6a1f7742 100644
--- a/sprout/complex/atanh.hpp
+++ b/sprout/complex/atanh.hpp
@@ -17,7 +17,7 @@
 #include <sprout/math/log.hpp>
 #include <sprout/math/atan2.hpp>
 #include <sprout/complex/complex.hpp>
-#include <sprout/complex/operators.hpp>
+#include <sprout/complex/arithmetic_operators.hpp>
 #include <sprout/complex/log.hpp>
 #include <sprout/complex/sqrt.hpp>
 
diff --git a/sprout/complex/cosh.hpp b/sprout/complex/cosh.hpp
index 934b998f..0e73d8dc 100644
--- a/sprout/complex/cosh.hpp
+++ b/sprout/complex/cosh.hpp
@@ -18,7 +18,7 @@
 #include <sprout/math/cosh.hpp>
 #include <sprout/math/sinh.hpp>
 #include <sprout/complex/complex.hpp>
-#include <sprout/complex/operators.hpp>
+#include <sprout/complex/arithmetic_operators.hpp>
 #include <sprout/complex/euler.hpp>
 #include <sprout/complex/detail/copysign_mul.hpp>
 
diff --git a/sprout/complex/log10.hpp b/sprout/complex/log10.hpp
index 6d713d76..5f66a13a 100644
--- a/sprout/complex/log10.hpp
+++ b/sprout/complex/log10.hpp
@@ -12,7 +12,7 @@
 #include <sprout/math/constants.hpp>
 #include <sprout/math/isnan.hpp>
 #include <sprout/complex/complex.hpp>
-#include <sprout/complex/operators.hpp>
+#include <sprout/complex/arithmetic_operators.hpp>
 #include <sprout/complex/log.hpp>
 
 namespace sprout {
diff --git a/sprout/complex/log2.hpp b/sprout/complex/log2.hpp
index 2e60b29e..a1a1dbb5 100644
--- a/sprout/complex/log2.hpp
+++ b/sprout/complex/log2.hpp
@@ -12,7 +12,7 @@
 #include <sprout/math/constants.hpp>
 #include <sprout/math/isnan.hpp>
 #include <sprout/complex/complex.hpp>
-#include <sprout/complex/operators.hpp>
+#include <sprout/complex/arithmetic_operators.hpp>
 #include <sprout/complex/log.hpp>
 
 namespace sprout {
diff --git a/sprout/complex/operators.hpp b/sprout/complex/operators.hpp
index e7a8d489..b65b7f1b 100644
--- a/sprout/complex/operators.hpp
+++ b/sprout/complex/operators.hpp
@@ -1,170 +1,15 @@
-/*=============================================================================
-  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_COMPLEX_OPERATORS_HPP
-#define SPROUT_COMPLEX_OPERATORS_HPP
-
-#include <istream>
-#include <ostream>
-#include <sprout/config.hpp>
-#include <sprout/complex/complex.hpp>
-
-namespace sprout {
-	// 26.4.6, operators:
-	template<typename T>
-	inline SPROUT_CONSTEXPR sprout::complex<T>
-	operator+(sprout::complex<T> const& lhs, sprout::complex<T> const& rhs) {
-		return sprout::complex<T>(lhs.real() + rhs.real(), lhs.imag() + rhs.imag());
-	}
-	template<typename T>
-	inline SPROUT_CONSTEXPR sprout::complex<T>
-	operator+(sprout::complex<T> const& lhs, T const& rhs) {
-		return sprout::complex<T>(lhs.real() + rhs, lhs.imag());
-	}
-	template<typename T>
-	inline SPROUT_CONSTEXPR sprout::complex<T>
-	operator+(T const& lhs, sprout::complex<T> const& rhs) {
-		return sprout::complex<T>(lhs + rhs.real(), rhs.imag());
-	}
-	template<typename T>
-	inline SPROUT_CONSTEXPR sprout::complex<T>
-	operator-(sprout::complex<T> const& lhs, sprout::complex<T> const& rhs) {
-		return sprout::complex<T>(lhs.real() - rhs.real(), lhs.imag() - rhs.imag());
-	}
-	template<typename T>
-	inline SPROUT_CONSTEXPR sprout::complex<T>
-	operator-(sprout::complex<T> const& lhs, T const& rhs) {
-		return sprout::complex<T>(lhs.real() - rhs, lhs.imag());
-	}
-	template<typename T>
-	inline SPROUT_CONSTEXPR sprout::complex<T>
-	operator-(T const& lhs, sprout::complex<T> const& rhs) {
-		return sprout::complex<T>(lhs - rhs.real(), -rhs.imag());
-	}
-	template<typename T>
-	inline SPROUT_CONSTEXPR sprout::complex<T>
-	operator*(sprout::complex<T> const& lhs, sprout::complex<T> const& rhs) {
-		return sprout::complex<T>(
-			lhs.real() * rhs.real() - lhs.imag() * rhs.imag(),
-			lhs.real() * rhs.imag() + lhs.imag() * rhs.real()
-			);
-	}
-	template<typename T>
-	inline SPROUT_CONSTEXPR sprout::complex<T>
-	operator*(sprout::complex<T> const& lhs, T const& rhs) {
-		return sprout::complex<T>(lhs.real() * rhs, lhs.imag() * rhs);
-	}
-	template<typename T>
-	inline SPROUT_CONSTEXPR sprout::complex<T>
-	operator*(T const& lhs, sprout::complex<T> const& rhs) {
-		return sprout::complex<T>(lhs * rhs.real(), lhs * rhs.imag());
-	}
-	namespace detail {
-		template<typename T>
-		inline SPROUT_CONSTEXPR sprout::complex<T>
-		divides_impl(sprout::complex<T> const& lhs, sprout::complex<T> const& rhs, T const& n) {
-			return sprout::complex<T>(
-				(lhs.real() * rhs.real() + lhs.imag() * rhs.imag()) / n,
-				(lhs.imag() * rhs.real() - lhs.real() * rhs.imag()) / n
-				);
-		}
-		template<typename T>
-		inline SPROUT_CONSTEXPR sprout::complex<T>
-		divides_impl(T const& lhs, sprout::complex<T> const& rhs, T const& n) {
-			return sprout::complex<T>(lhs * rhs.real() / n, -lhs * rhs.imag() / n);
-		}
-	}	// namespace detail
-	template<typename T>
-	inline SPROUT_CONSTEXPR sprout::complex<T>
-	operator/(sprout::complex<T> const& lhs, sprout::complex<T> const& rhs) {
-		return sprout::detail::divides_impl(lhs, rhs, sprout::detail::complex_norm(rhs));
-	}
-	template<typename T>
-	inline SPROUT_CONSTEXPR sprout::complex<T>
-	operator/(sprout::complex<T> const& lhs, T const& rhs) {
-		return sprout::complex<T>(lhs.real() / rhs, lhs.imag() / rhs);
-	}
-	template<typename T>
-	inline SPROUT_CONSTEXPR sprout::complex<T>
-	operator/(T const& lhs, sprout::complex<T> const& rhs) {
-		return sprout::detail::divides_impl(lhs, rhs, sprout::detail::complex_norm(rhs));
-	}
-	template<typename T>
-	inline SPROUT_CONSTEXPR sprout::complex<T>
-	operator+(sprout::complex<T> const& x) {
-		return x;
-	}
-	template<typename T>
-	inline SPROUT_CONSTEXPR sprout::complex<T>
-	operator-(sprout::complex<T> const& x) {
-		return sprout::complex<T>(-x.real(), -x.imag());
-	}
-	template<typename T>
-	inline SPROUT_CONSTEXPR bool
-	operator==(sprout::complex<T> const& lhs, sprout::complex<T> const& rhs) {
-		return lhs.real() == rhs.real() && lhs.imag() == rhs.imag();
-	}
-	template<typename T>
-	inline SPROUT_CONSTEXPR bool
-	operator==(sprout::complex<T> const& lhs, T const& rhs) {
-		return lhs.real() == rhs && lhs.imag() == T();
-	}
-	template<typename T>
-	inline SPROUT_CONSTEXPR bool
-	operator==(T const& lhs, sprout::complex<T> const& rhs) {
-		return lhs == rhs.real() && T() == rhs.imag();
-	}
-	template<typename T>
-	inline SPROUT_CONSTEXPR bool
-	operator!=(sprout::complex<T> const& lhs, sprout::complex<T> const& rhs) {
-		return !(lhs == rhs);
-	}
-	template<typename T>
-	inline SPROUT_CONSTEXPR bool
-	operator!=(sprout::complex<T> const& lhs, T const& rhs) {
-		return !(lhs == rhs);
-	}
-	template<typename T>
-	inline SPROUT_CONSTEXPR bool
-	operator!=(T const& lhs, sprout::complex<T> const& rhs) {
-		return !(lhs == rhs);
-	}
-	template<typename T, typename Char, typename Traits>
-	inline SPROUT_NON_CONSTEXPR std::basic_istream<Char, Traits>&
-	operator>>(std::basic_istream<Char, Traits>& lhs, sprout::complex<T>& rhs) {
-		T re, im;
-		Char ch;
-		lhs >> ch;
-		if (ch == '(') {
-			lhs >> re >> ch;
-			if (ch == ',') {
-				lhs >> im >> ch;
-				if (ch == ')') {
-					rhs = sprout::complex<T>(re, im);
-				} else {
-					lhs.setstate(std::ios_base::failbit);
-				}
-			} else if (ch == ')') {
-				rhs = re;
-			} else {
-				lhs.setstate(std::ios_base::failbit);
-			}
-		} else {
-			lhs.putback(ch);
-			lhs >> re;
-			rhs = re;
-		}
-		return lhs;
-	}
-	template<typename T, typename Char, typename Traits>
-	inline SPROUT_NON_CONSTEXPR std::basic_ostream<Char, Traits>&
-	operator<<(std::basic_ostream<Char, Traits>& lhs, sprout::complex<T> const& rhs) {
-		return lhs << '(' << rhs.real() << ',' << rhs.imag() << ')';
-	}
-}	// namespace sprout
-
-#endif	// #ifndef SPROUT_COMPLEX_OPERATORS_HPP
+/*=============================================================================
+  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_COMPLEX_OPERATORS_HPP
+#define SPROUT_COMPLEX_OPERATORS_HPP
+
+#include <sprout/complex/arithmetic_operators.hpp>
+#include <sprout/complex/stream_operators.hpp>
+
+#endif	// #ifndef SPROUT_COMPLEX_OPERATORS_HPP
+
diff --git a/sprout/complex/pow.hpp b/sprout/complex/pow.hpp
index 34b1b189..709f0317 100644
--- a/sprout/complex/pow.hpp
+++ b/sprout/complex/pow.hpp
@@ -11,7 +11,7 @@
 #include <sprout/config.hpp>
 #include <sprout/math/pow.hpp>
 #include <sprout/complex/complex.hpp>
-#include <sprout/complex/operators.hpp>
+#include <sprout/complex/arithmetic_operators.hpp>
 #include <sprout/complex/exp.hpp>
 #include <sprout/complex/log.hpp>
 
diff --git a/sprout/complex/sin.hpp b/sprout/complex/sin.hpp
index 37de93c8..2d689a65 100644
--- a/sprout/complex/sin.hpp
+++ b/sprout/complex/sin.hpp
@@ -10,7 +10,7 @@
 
 #include <sprout/config.hpp>
 #include <sprout/complex/complex.hpp>
-#include <sprout/complex/operators.hpp>
+#include <sprout/complex/arithmetic_operators.hpp>
 #include <sprout/complex/perp.hpp>
 #include <sprout/complex/sinh.hpp>
 
diff --git a/sprout/complex/sinh.hpp b/sprout/complex/sinh.hpp
index db871d44..bd9c14f2 100644
--- a/sprout/complex/sinh.hpp
+++ b/sprout/complex/sinh.hpp
@@ -17,7 +17,7 @@
 #include <sprout/math/cosh.hpp>
 #include <sprout/math/sinh.hpp>
 #include <sprout/complex/complex.hpp>
-#include <sprout/complex/operators.hpp>
+#include <sprout/complex/arithmetic_operators.hpp>
 #include <sprout/complex/euler.hpp>
 #include <sprout/complex/detail/copysign_mul.hpp>
 
diff --git a/sprout/complex/stream_operators.hpp b/sprout/complex/stream_operators.hpp
new file mode 100644
index 00000000..c51da3cd
--- /dev/null
+++ b/sprout/complex/stream_operators.hpp
@@ -0,0 +1,51 @@
+/*=============================================================================
+  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_COMPLEX_STREAM_OPERATORS_HPP
+#define SPROUT_COMPLEX_STREAM_OPERATORS_HPP
+
+#include <istream>
+#include <ostream>
+#include <sprout/config.hpp>
+#include <sprout/complex/complex.hpp>
+
+namespace sprout {
+	template<typename T, typename Char, typename Traits>
+	inline SPROUT_NON_CONSTEXPR std::basic_istream<Char, Traits>&
+	operator>>(std::basic_istream<Char, Traits>& lhs, sprout::complex<T>& rhs) {
+		T re, im;
+		Char ch;
+		lhs >> ch;
+		if (ch == '(') {
+			lhs >> re >> ch;
+			if (ch == ',') {
+				lhs >> im >> ch;
+				if (ch == ')') {
+					rhs = sprout::complex<T>(re, im);
+				} else {
+					lhs.setstate(std::ios_base::failbit);
+				}
+			} else if (ch == ')') {
+				rhs = re;
+			} else {
+				lhs.setstate(std::ios_base::failbit);
+			}
+		} else {
+			lhs.putback(ch);
+			lhs >> re;
+			rhs = re;
+		}
+		return lhs;
+	}
+	template<typename T, typename Char, typename Traits>
+	inline SPROUT_NON_CONSTEXPR std::basic_ostream<Char, Traits>&
+	operator<<(std::basic_ostream<Char, Traits>& lhs, sprout::complex<T> const& rhs) {
+		return lhs << '(' << rhs.real() << ',' << rhs.imag() << ')';
+	}
+}	// namespace sprout
+
+#endif	// #ifndef SPROUT_COMPLEX_STREAM_OPERATORS_HPP
diff --git a/sprout/complex/tan.hpp b/sprout/complex/tan.hpp
index 5d98aa1c..9c308da3 100644
--- a/sprout/complex/tan.hpp
+++ b/sprout/complex/tan.hpp
@@ -10,7 +10,7 @@
 
 #include <sprout/config.hpp>
 #include <sprout/complex/complex.hpp>
-#include <sprout/complex/operators.hpp>
+#include <sprout/complex/arithmetic_operators.hpp>
 #include <sprout/complex/perp.hpp>
 #include <sprout/complex/tanh.hpp>
 
diff --git a/sprout/complex/tanh.hpp b/sprout/complex/tanh.hpp
index 99abef61..313a5e86 100644
--- a/sprout/complex/tanh.hpp
+++ b/sprout/complex/tanh.hpp
@@ -15,7 +15,7 @@
 #include <sprout/math/sin.hpp>
 #include <sprout/math/copysign.hpp>
 #include <sprout/complex/complex.hpp>
-#include <sprout/complex/operators.hpp>
+#include <sprout/complex/arithmetic_operators.hpp>
 #include <sprout/complex/cosh.hpp>
 #include <sprout/complex/sinh.hpp>
 
diff --git a/sprout/math/quaternion.hpp b/sprout/math/quaternion.hpp
index 499ad207..afbd527b 100644
--- a/sprout/math/quaternion.hpp
+++ b/sprout/math/quaternion.hpp
@@ -10,7 +10,8 @@
 
 #include <sprout/config.hpp>
 #include <sprout/math/quaternion/quaternion.hpp>
-#include <sprout/math/quaternion/operators.hpp>
+#include <sprout/math/quaternion/arithmetic_operators.hpp>
+#include <sprout/math/quaternion/stream_operators.hpp>
 #include <sprout/math/quaternion/values.hpp>
 #include <sprout/math/quaternion/creations.hpp>
 #include <sprout/math/quaternion/transcendentals.hpp>
diff --git a/sprout/math/quaternion/arithmetic_operators.hpp b/sprout/math/quaternion/arithmetic_operators.hpp
new file mode 100644
index 00000000..41930e51
--- /dev/null
+++ b/sprout/math/quaternion/arithmetic_operators.hpp
@@ -0,0 +1,381 @@
+/*=============================================================================
+  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_QUATERNION_ARITHMETIC_OPERATORS_HPP
+#define SPROUT_MATH_QUATERNION_ARITHMETIC_OPERATORS_HPP
+
+#include <sprout/config.hpp>
+#include <sprout/math/quaternion/quaternion.hpp>
+
+namespace sprout {
+	namespace math {
+		//
+		// operator+
+		//
+		template<typename T>
+		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
+		operator+(T const& lhs, sprout::math::quaternion<T> const& rhs) {
+			return sprout::math::quaternion<T>(
+				lhs + rhs.R_component_1(),
+				rhs.R_component_2(),
+				rhs.R_component_3(),
+				rhs.R_component_4()
+				);
+		}
+		template<typename T>
+		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
+		operator+(sprout::math::quaternion<T> const& lhs, T const& rhs) {
+			return sprout::math::quaternion<T>(
+				lhs.R_component_1() + rhs,
+				lhs.R_component_2(),
+				lhs.R_component_3(),
+				lhs.R_component_4()
+				);
+		}
+		template<typename T>
+		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
+		operator+(sprout::complex<T> const& lhs, sprout::math::quaternion<T> const& rhs) {
+			return sprout::math::quaternion<T>(
+				lhs.real() + rhs.R_component_1(),
+				lhs.imag() + rhs.R_component_2(),
+				rhs.R_component_3(),
+				rhs.R_component_4()
+				);
+		}
+		template<typename T>
+		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
+		operator+(sprout::math::quaternion<T> const& lhs, sprout::complex<T> const& rhs) {
+			return sprout::math::quaternion<T>(
+				lhs.R_component_1() + rhs.real(),
+				lhs.R_component_2() + rhs.imag(),
+				lhs.R_component_3(),
+				lhs.R_component_4()
+				);
+		}
+		template<typename T>
+		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
+		operator+(sprout::math::quaternion<T> const& lhs, sprout::math::quaternion<T> const& rhs) {
+			return sprout::math::quaternion<T>(
+				lhs.R_component_1() + rhs.R_component_1(),
+				lhs.R_component_2() + rhs.R_component_2(),
+				lhs.R_component_3() + rhs.R_component_3(),
+				lhs.R_component_4() + rhs.R_component_4()
+				);
+		}
+		//
+		// operator-
+		//
+		template<typename T>
+		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
+		operator-(T const& lhs, sprout::math::quaternion<T> const& rhs) {
+			return sprout::math::quaternion<T>(
+				lhs - rhs.R_component_1(),
+				rhs.R_component_2(),
+				rhs.R_component_3(),
+				rhs.R_component_4()
+				);
+		}
+		template<typename T>
+		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
+		operator-(sprout::math::quaternion<T> const& lhs, T const& rhs) {
+			return sprout::math::quaternion<T>(
+				lhs.R_component_1() - rhs,
+				lhs.R_component_2(),
+				lhs.R_component_3(),
+				lhs.R_component_4()
+				);
+		}
+		template<typename T>
+		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
+		operator-(sprout::complex<T> const& lhs, sprout::math::quaternion<T> const& rhs) {
+			return sprout::math::quaternion<T>(
+				lhs.real() - rhs.R_component_1(),
+				lhs.imag() - rhs.R_component_2(),
+				rhs.R_component_3(),
+				rhs.R_component_4()
+				);
+		}
+		template<typename T>
+		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
+		operator-(sprout::math::quaternion<T> const& lhs, sprout::complex<T> const& rhs) {
+			return sprout::math::quaternion<T>(
+				lhs.R_component_1() - rhs.real(),
+				lhs.R_component_2() - rhs.imag(),
+				lhs.R_component_3(),
+				lhs.R_component_4()
+				);
+		}
+		template<typename T>
+		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
+		operator-(sprout::math::quaternion<T> const& lhs, sprout::math::quaternion<T> const& rhs) {
+			return sprout::math::quaternion<T>(
+				lhs.R_component_1() - rhs.R_component_1(),
+				lhs.R_component_2() - rhs.R_component_2(),
+				lhs.R_component_3() - rhs.R_component_3(),
+				lhs.R_component_4() - rhs.R_component_4()
+				);
+		}
+		//
+		// operator*
+		//
+		template<typename T>
+		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
+		operator*(T const& lhs, sprout::math::quaternion<T> const& rhs) {
+			return sprout::math::quaternion<T>(
+				lhs * rhs.R_component_1(),
+				lhs * rhs.R_component_2(),
+				lhs * rhs.R_component_3(),
+				lhs * rhs.R_component_4()
+				);
+		}
+		template<typename T>
+		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
+		operator*(sprout::math::quaternion<T> const& lhs, T const& rhs) {
+			return sprout::math::quaternion<T>(
+				lhs.R_component_1() * rhs,
+				lhs.R_component_2() * rhs,
+				lhs.R_component_3() * rhs,
+				lhs.R_component_4() * rhs
+				);
+		}
+		namespace detail {
+			template<typename T>
+			inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
+			mul_qc_impl(T const& a, T const& b, T const& c, T const& d, T const& ar, T const& br) {
+				return sprout::math::quaternion<T>(
+					+a * ar - b * br,
+					+a * br + b * ar,
+					+c * ar + d * br,
+					-c * br + d * ar
+					);
+			}
+		}	// namespace detail
+		template<typename T>
+		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
+		operator*(sprout::complex<T> const& lhs, sprout::math::quaternion<T> const& rhs) {
+			return sprout::math::detail::mul_qc_impl(
+				lhs.R_component_1(), lhs.R_component_2(), lhs.R_component_3(), lhs.R_component_4(),
+				rhs.real(), rhs.imag()
+				);
+		}
+		template<typename T>
+		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
+		operator*(sprout::math::quaternion<T> const& lhs, sprout::complex<T> const& rhs) {
+			return sprout::math::detail::mul_qc_impl(
+				rhs.R_component_1(), rhs.R_component_2(), rhs.R_component_3(), rhs.R_component_4(),
+				lhs.real(), lhs.imag()
+				);
+		}
+		namespace detail {
+			template<typename T>
+			inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
+			mul_qq_impl(T const& a, T const& b, T const& c, T const& d, T const& ar, T const& br, T const& cr, T const& dr) {
+				return sprout::math::quaternion<T>(
+					+a * ar - b * br - c * cr - d * dr,
+					+a * br + b * ar + c * dr - d * cr,
+					+a * cr - b * dr + c * ar + d * br,
+					+a * dr + b * cr - c * br + d * ar
+					);
+			}
+		}	// namespace detail
+		template<typename T>
+		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
+		operator*(sprout::math::quaternion<T> const& lhs, sprout::math::quaternion<T> const& rhs) {
+			return sprout::math::detail::mul_qq_impl(
+				lhs.R_component_1(), lhs.R_component_2(), lhs.R_component_3(), lhs.R_component_4(),
+				rhs.R_component_1(), rhs.R_component_2(), rhs.R_component_3(), rhs.R_component_4()
+				);
+		}
+		//
+		// operator/
+		//
+		template<typename T>
+		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
+		operator/(T const& lhs, sprout::math::quaternion<T> const& rhs) {
+			return sprout::math::quaternion<T>(
+				lhs / rhs.R_component_1(),
+				lhs / rhs.R_component_2(),
+				lhs / rhs.R_component_3(),
+				lhs / rhs.R_component_4()
+				);
+		}
+		template<typename T>
+		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
+		operator/(sprout::math::quaternion<T> const& lhs, T const& rhs) {
+			return sprout::math::quaternion<T>(
+				lhs.R_component_1() / rhs,
+				lhs.R_component_2() / rhs,
+				lhs.R_component_3() / rhs,
+				lhs.R_component_4() / rhs
+				);
+		}
+		namespace detail {
+			template<typename T>
+			inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
+			div_qq_impl_4(sprout::array<T, 4> const& tt) {
+				return sprout::math::quaternion<T>(
+					tt[0], tt[1], tt[2], tt[3]
+					);
+			}
+			template<typename T>
+			inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
+			div_qq_impl_3(sprout::array<T, 4> const& tr, T const& mixam, sprout::array<T, 4> const& tt) {
+				return sprout::math::detail::div_qq_impl_3(
+					sprout::math::detail::mul(tt, mixam / sprout::math::detail::sum(tr))
+					);
+			}
+			template<typename T>
+			inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
+			div_qq_impl_2(T const& a, T const& b, T const& c, T const& d, sprout::array<T, 4> const& tr, T const& mixam) {
+				return sprout::math::detail::div_qq_impl_3(
+					sprout::math::detail::mul(tr, tr), mixam,
+					sprout::array<T, 4>{{
+						+a * tr[0] + b * tr[1] + c * tr[2] + d * tr[3],
+						-a * tr[1] + b * tr[0] - c * tr[3] + d * tr[2],
+						-a * tr[2] + b * tr[3] + c * tr[0] - d * tr[1],
+						-a * tr[3] - b * tr[2] + c * tr[1] + d * tr[0]
+						}}
+					);
+			}
+			template<typename T>
+			inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
+			div_qq_impl_1(T const& a, T const& b, T const& c, T const& d, sprout::array<T, 4> const& tr, T const& mixam) {
+				return sprout::math::detail::div_qq_impl_2(
+					a, b, c, d, sprout::math::detail::mul(tr, mixam), mixam
+					);
+			}
+			template<typename T>
+			inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
+			div_qq_impl(T const& a, T const& b, T const& c, T const& d, sprout::array<T, 4> const& tr) {
+				return sprout::math::detail::div_qq_impl_1(
+					a, b, c, d, tr,
+					static_cast<T>(1) / sprout::math::detail::abs_max(tr)
+					);
+			}
+		}	// namespace detail
+		template<typename T>
+		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
+		operator/(sprout::complex<T> const& lhs, sprout::math::quaternion<T> const& rhs) {
+			return sprout::math::detail::div_qq_impl(
+				lhs.real(), lhs.imag(), static_cast<T>(0), static_cast<T>(0),
+				sprout::array<T, 4>{{rhs.R_component_1(), rhs.R_component_2(), rhs.R_component_3(), rhs.R_component_4()}}
+				);
+		}
+		template<typename T>
+		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
+		operator/(sprout::math::quaternion<T> const& lhs, sprout::complex<T> const& rhs) {
+			return sprout::math::detail::div_qq_impl(
+				lhs.R_component_1(), lhs.R_component_2(), lhs.R_component_3(), lhs.R_component_4(),
+				sprout::array<T, 4>{{rhs.real(), rhs.imag(), static_cast<T>(0), static_cast<T>(0)}}
+				);
+		}
+		template<typename T>
+		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
+		operator/(sprout::math::quaternion<T> const& lhs, sprout::math::quaternion<T> const& rhs) {
+			return sprout::math::detail::div_qq_impl(
+				lhs.R_component_1(), lhs.R_component_2(), lhs.R_component_3(), lhs.R_component_4(),
+				sprout::array<T, 4>{{rhs.R_component_1(), rhs.R_component_2(), rhs.R_component_3(), rhs.R_component_4()}}
+				);
+		}
+
+		//
+		// operator+
+		// operator-
+		//
+		template<typename T>
+		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
+		operator+(sprout::math::quaternion<T> const& q) {
+			return q;
+		}
+		template<typename T>
+		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
+		operator-(sprout::math::quaternion<T> const& q) {
+			return sprout::math::quaternion<T>(-q.R_component_1(), -q.R_component_2(), -q.R_component_3(), -q.R_component_4());
+		}
+
+		//
+		// operator==
+		// operator!=
+		//
+		template<typename T>
+		inline SPROUT_CONSTEXPR bool
+		operator==(T const& lhs, sprout::math::quaternion<T> const& rhs) {
+			return rhs.R_component_1() == lhs
+				&& rhs.R_component_2() == static_cast<T>(0)
+				&& rhs.R_component_3() == static_cast<T>(0)
+				&& rhs.R_component_4() == static_cast<T>(0)
+				;
+		}
+		template<typename T>
+		inline SPROUT_CONSTEXPR bool
+		operator==(sprout::math::quaternion<T> const& lhs, T const& rhs) {
+			return lhs.R_component_1() == rhs
+				&& lhs.R_component_2() == static_cast<T>(0)
+				&& lhs.R_component_3() == static_cast<T>(0)
+				&& lhs.R_component_4() == static_cast<T>(0)
+				;
+		}
+		template<typename T>
+		inline SPROUT_CONSTEXPR bool
+		operator==(sprout::complex<T> const& lhs, sprout::math::quaternion<T> const& rhs) {
+			return rhs.R_component_1() == lhs.real()
+				&& rhs.R_component_2() == lhs.imag()
+				&& rhs.R_component_3() == static_cast<T>(0)
+				&& rhs.R_component_4() == static_cast<T>(0)
+				;
+		}
+		template<typename T>
+		inline SPROUT_CONSTEXPR bool
+		operator==(sprout::math::quaternion<T> const& lhs, sprout::complex<T> const& rhs) {
+			return lhs.R_component_1() == rhs.real()
+				&& lhs.R_component_2() == rhs.imag()
+				&& lhs.R_component_3() == static_cast<T>(0)
+				&& lhs.R_component_4() == static_cast<T>(0)
+				;
+		}
+		template<typename T>
+		inline SPROUT_CONSTEXPR bool
+		operator==(sprout::math::quaternion<T> const& lhs, sprout::math::quaternion<T> const& rhs) {
+			return rhs.R_component_1() == lhs.R_component_1()
+				&& rhs.R_component_2() == lhs.R_component_2()
+				&& rhs.R_component_3() == lhs.R_component_3()
+				&& rhs.R_component_4() == lhs.R_component_4()
+				;
+		}
+
+#define	SPROUT_QUATERNION_NOT_EQUAL_GENERATOR \
+		{ \
+			return !(lhs == rhs); \
+		}
+
+		template<typename T>
+		inline SPROUT_CONSTEXPR bool
+		operator!=(T const& lhs, sprout::math::quaternion<T> const& rhs)
+		SPROUT_QUATERNION_NOT_EQUAL_GENERATOR
+		template<typename T>
+		inline SPROUT_CONSTEXPR bool
+		operator!=(sprout::math::quaternion<T> const& lhs, T const& rhs)
+		SPROUT_QUATERNION_NOT_EQUAL_GENERATOR
+		template<typename T>
+		inline SPROUT_CONSTEXPR bool
+		operator!=(sprout::complex<T> const& lhs, sprout::math::quaternion<T> const& rhs)
+		SPROUT_QUATERNION_NOT_EQUAL_GENERATOR
+		template<typename T>
+		inline SPROUT_CONSTEXPR bool
+		operator!=(sprout::math::quaternion<T> const& lhs, sprout::complex<T> const& rhs)
+		SPROUT_QUATERNION_NOT_EQUAL_GENERATOR
+		template<typename T>
+		inline SPROUT_CONSTEXPR bool
+		operator!=(sprout::math::quaternion<T> const& lhs, sprout::math::quaternion<T> const& rhs)
+		SPROUT_QUATERNION_NOT_EQUAL_GENERATOR
+
+#undef	SPROUT_QUATERNION_NOT_EQUAL_GENERATOR
+
+	}	// namespace math
+}	// namespace sprout
+
+#endif	// #ifndef SPROUT_MATH_QUATERNION_ARITHMETIC_OPERATORS_HPP
diff --git a/sprout/math/quaternion/norm.hpp b/sprout/math/quaternion/norm.hpp
index 391dbbb7..947246de 100644
--- a/sprout/math/quaternion/norm.hpp
+++ b/sprout/math/quaternion/norm.hpp
@@ -10,7 +10,7 @@
 
 #include <sprout/config.hpp>
 #include <sprout/math/quaternion/quaternion.hpp>
-#include <sprout/math/quaternion/operators.hpp>
+#include <sprout/math/quaternion/arithmetic_operators.hpp>
 #include <sprout/math/quaternion/real.hpp>
 #include <sprout/math/quaternion/conj.hpp>
 
diff --git a/sprout/math/quaternion/operators.hpp b/sprout/math/quaternion/operators.hpp
index 5f20baaf..57958b6d 100644
--- a/sprout/math/quaternion/operators.hpp
+++ b/sprout/math/quaternion/operators.hpp
@@ -8,555 +8,7 @@
 #ifndef SPROUT_MATH_QUATERNION_OPERATORS_HPP
 #define SPROUT_MATH_QUATERNION_OPERATORS_HPP
 
-#include <iosfwd>
-#include <sstream>
-#include <locale>
-#include <sprout/config.hpp>
-#include <sprout/math/quaternion/quaternion.hpp>
-
-namespace sprout {
-	namespace math {
-		//
-		// operator+
-		//
-		template<typename T>
-		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
-		operator+(T const& lhs, sprout::math::quaternion<T> const& rhs) {
-			return sprout::math::quaternion<T>(
-				lhs + rhs.R_component_1(),
-				rhs.R_component_2(),
-				rhs.R_component_3(),
-				rhs.R_component_4()
-				);
-		}
-		template<typename T>
-		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
-		operator+(sprout::math::quaternion<T> const& lhs, T const& rhs) {
-			return sprout::math::quaternion<T>(
-				lhs.R_component_1() + rhs,
-				lhs.R_component_2(),
-				lhs.R_component_3(),
-				lhs.R_component_4()
-				);
-		}
-		template<typename T>
-		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
-		operator+(sprout::complex<T> const& lhs, sprout::math::quaternion<T> const& rhs) {
-			return sprout::math::quaternion<T>(
-				lhs.real() + rhs.R_component_1(),
-				lhs.imag() + rhs.R_component_2(),
-				rhs.R_component_3(),
-				rhs.R_component_4()
-				);
-		}
-		template<typename T>
-		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
-		operator+(sprout::math::quaternion<T> const& lhs, sprout::complex<T> const& rhs) {
-			return sprout::math::quaternion<T>(
-				lhs.R_component_1() + rhs.real(),
-				lhs.R_component_2() + rhs.imag(),
-				lhs.R_component_3(),
-				lhs.R_component_4()
-				);
-		}
-		template<typename T>
-		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
-		operator+(sprout::math::quaternion<T> const& lhs, sprout::math::quaternion<T> const& rhs) {
-			return sprout::math::quaternion<T>(
-				lhs.R_component_1() + rhs.R_component_1(),
-				lhs.R_component_2() + rhs.R_component_2(),
-				lhs.R_component_3() + rhs.R_component_3(),
-				lhs.R_component_4() + rhs.R_component_4()
-				);
-		}
-		//
-		// operator-
-		//
-		template<typename T>
-		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
-		operator-(T const& lhs, sprout::math::quaternion<T> const& rhs) {
-			return sprout::math::quaternion<T>(
-				lhs - rhs.R_component_1(),
-				rhs.R_component_2(),
-				rhs.R_component_3(),
-				rhs.R_component_4()
-				);
-		}
-		template<typename T>
-		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
-		operator-(sprout::math::quaternion<T> const& lhs, T const& rhs) {
-			return sprout::math::quaternion<T>(
-				lhs.R_component_1() - rhs,
-				lhs.R_component_2(),
-				lhs.R_component_3(),
-				lhs.R_component_4()
-				);
-		}
-		template<typename T>
-		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
-		operator-(sprout::complex<T> const& lhs, sprout::math::quaternion<T> const& rhs) {
-			return sprout::math::quaternion<T>(
-				lhs.real() - rhs.R_component_1(),
-				lhs.imag() - rhs.R_component_2(),
-				rhs.R_component_3(),
-				rhs.R_component_4()
-				);
-		}
-		template<typename T>
-		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
-		operator-(sprout::math::quaternion<T> const& lhs, sprout::complex<T> const& rhs) {
-			return sprout::math::quaternion<T>(
-				lhs.R_component_1() - rhs.real(),
-				lhs.R_component_2() - rhs.imag(),
-				lhs.R_component_3(),
-				lhs.R_component_4()
-				);
-		}
-		template<typename T>
-		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
-		operator-(sprout::math::quaternion<T> const& lhs, sprout::math::quaternion<T> const& rhs) {
-			return sprout::math::quaternion<T>(
-				lhs.R_component_1() - rhs.R_component_1(),
-				lhs.R_component_2() - rhs.R_component_2(),
-				lhs.R_component_3() - rhs.R_component_3(),
-				lhs.R_component_4() - rhs.R_component_4()
-				);
-		}
-		//
-		// operator*
-		//
-		template<typename T>
-		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
-		operator*(T const& lhs, sprout::math::quaternion<T> const& rhs) {
-			return sprout::math::quaternion<T>(
-				lhs * rhs.R_component_1(),
-				lhs * rhs.R_component_2(),
-				lhs * rhs.R_component_3(),
-				lhs * rhs.R_component_4()
-				);
-		}
-		template<typename T>
-		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
-		operator*(sprout::math::quaternion<T> const& lhs, T const& rhs) {
-			return sprout::math::quaternion<T>(
-				lhs.R_component_1() * rhs,
-				lhs.R_component_2() * rhs,
-				lhs.R_component_3() * rhs,
-				lhs.R_component_4() * rhs
-				);
-		}
-		namespace detail {
-			template<typename T>
-			inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
-			mul_qc_impl(T const& a, T const& b, T const& c, T const& d, T const& ar, T const& br) {
-				return sprout::math::quaternion<T>(
-					+a * ar - b * br,
-					+a * br + b * ar,
-					+c * ar + d * br,
-					-c * br + d * ar
-					);
-			}
-		}	// namespace detail
-		template<typename T>
-		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
-		operator*(sprout::complex<T> const& lhs, sprout::math::quaternion<T> const& rhs) {
-			return sprout::math::detail::mul_qc_impl(
-				lhs.R_component_1(), lhs.R_component_2(), lhs.R_component_3(), lhs.R_component_4(),
-				rhs.real(), rhs.imag()
-				);
-		}
-		template<typename T>
-		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
-		operator*(sprout::math::quaternion<T> const& lhs, sprout::complex<T> const& rhs) {
-			return sprout::math::detail::mul_qc_impl(
-				rhs.R_component_1(), rhs.R_component_2(), rhs.R_component_3(), rhs.R_component_4(),
-				lhs.real(), lhs.imag()
-				);
-		}
-		namespace detail {
-			template<typename T>
-			inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
-			mul_qq_impl(T const& a, T const& b, T const& c, T const& d, T const& ar, T const& br, T const& cr, T const& dr) {
-				return sprout::math::quaternion<T>(
-					+a * ar - b * br - c * cr - d * dr,
-					+a * br + b * ar + c * dr - d * cr,
-					+a * cr - b * dr + c * ar + d * br,
-					+a * dr + b * cr - c * br + d * ar
-					);
-			}
-		}	// namespace detail
-		template<typename T>
-		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
-		operator*(sprout::math::quaternion<T> const& lhs, sprout::math::quaternion<T> const& rhs) {
-			return sprout::math::detail::mul_qq_impl(
-				lhs.R_component_1(), lhs.R_component_2(), lhs.R_component_3(), lhs.R_component_4(),
-				rhs.R_component_1(), rhs.R_component_2(), rhs.R_component_3(), rhs.R_component_4()
-				);
-		}
-		//
-		// operator/
-		//
-		template<typename T>
-		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
-		operator/(T const& lhs, sprout::math::quaternion<T> const& rhs) {
-			return sprout::math::quaternion<T>(
-				lhs / rhs.R_component_1(),
-				lhs / rhs.R_component_2(),
-				lhs / rhs.R_component_3(),
-				lhs / rhs.R_component_4()
-				);
-		}
-		template<typename T>
-		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
-		operator/(sprout::math::quaternion<T> const& lhs, T const& rhs) {
-			return sprout::math::quaternion<T>(
-				lhs.R_component_1() / rhs,
-				lhs.R_component_2() / rhs,
-				lhs.R_component_3() / rhs,
-				lhs.R_component_4() / rhs
-				);
-		}
-		namespace detail {
-			template<typename T>
-			inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
-			div_qq_impl_4(sprout::array<T, 4> const& tt) {
-				return sprout::math::quaternion<T>(
-					tt[0], tt[1], tt[2], tt[3]
-					);
-			}
-			template<typename T>
-			inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
-			div_qq_impl_3(sprout::array<T, 4> const& tr, T const& mixam, sprout::array<T, 4> const& tt) {
-				return sprout::math::detail::div_qq_impl_3(
-					sprout::math::detail::mul(tt, mixam / sprout::math::detail::sum(tr))
-					);
-			}
-			template<typename T>
-			inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
-			div_qq_impl_2(T const& a, T const& b, T const& c, T const& d, sprout::array<T, 4> const& tr, T const& mixam) {
-				return sprout::math::detail::div_qq_impl_3(
-					sprout::math::detail::mul(tr, tr), mixam,
-					sprout::array<T, 4>{{
-						+a * tr[0] + b * tr[1] + c * tr[2] + d * tr[3],
-						-a * tr[1] + b * tr[0] - c * tr[3] + d * tr[2],
-						-a * tr[2] + b * tr[3] + c * tr[0] - d * tr[1],
-						-a * tr[3] - b * tr[2] + c * tr[1] + d * tr[0]
-						}}
-					);
-			}
-			template<typename T>
-			inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
-			div_qq_impl_1(T const& a, T const& b, T const& c, T const& d, sprout::array<T, 4> const& tr, T const& mixam) {
-				return sprout::math::detail::div_qq_impl_2(
-					a, b, c, d, sprout::math::detail::mul(tr, mixam), mixam
-					);
-			}
-			template<typename T>
-			inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
-			div_qq_impl(T const& a, T const& b, T const& c, T const& d, sprout::array<T, 4> const& tr) {
-				return sprout::math::detail::div_qq_impl_1(
-					a, b, c, d, tr,
-					static_cast<T>(1) / sprout::math::detail::abs_max(tr)
-					);
-			}
-		}	// namespace detail
-		template<typename T>
-		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
-		operator/(sprout::complex<T> const& lhs, sprout::math::quaternion<T> const& rhs) {
-			return sprout::math::detail::div_qq_impl(
-				lhs.real(), lhs.imag(), static_cast<T>(0), static_cast<T>(0),
-				sprout::array<T, 4>{{rhs.R_component_1(), rhs.R_component_2(), rhs.R_component_3(), rhs.R_component_4()}}
-				);
-		}
-		template<typename T>
-		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
-		operator/(sprout::math::quaternion<T> const& lhs, sprout::complex<T> const& rhs) {
-			return sprout::math::detail::div_qq_impl(
-				lhs.R_component_1(), lhs.R_component_2(), lhs.R_component_3(), lhs.R_component_4(),
-				sprout::array<T, 4>{{rhs.real(), rhs.imag(), static_cast<T>(0), static_cast<T>(0)}}
-				);
-		}
-		template<typename T>
-		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
-		operator/(sprout::math::quaternion<T> const& lhs, sprout::math::quaternion<T> const& rhs) {
-			return sprout::math::detail::div_qq_impl(
-				lhs.R_component_1(), lhs.R_component_2(), lhs.R_component_3(), lhs.R_component_4(),
-				sprout::array<T, 4>{{rhs.R_component_1(), rhs.R_component_2(), rhs.R_component_3(), rhs.R_component_4()}}
-				);
-		}
-
-		//
-		// operator+
-		// operator-
-		//
-		template<typename T>
-		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
-		operator+(sprout::math::quaternion<T> const& q) {
-			return q;
-		}
-		template<typename T>
-		inline SPROUT_CONSTEXPR sprout::math::quaternion<T>
-		operator-(sprout::math::quaternion<T> const& q) {
-			return sprout::math::quaternion<T>(-q.R_component_1(), -q.R_component_2(), -q.R_component_3(), -q.R_component_4());
-		}
-
-		//
-		// operator==
-		// operator!=
-		//
-		template<typename T>
-		inline SPROUT_CONSTEXPR bool
-		operator==(T const& lhs, sprout::math::quaternion<T> const& rhs) {
-			return rhs.R_component_1() == lhs
-				&& rhs.R_component_2() == static_cast<T>(0)
-				&& rhs.R_component_3() == static_cast<T>(0)
-				&& rhs.R_component_4() == static_cast<T>(0)
-				;
-		}
-		template<typename T>
-		inline SPROUT_CONSTEXPR bool
-		operator==(sprout::math::quaternion<T> const& lhs, T const& rhs) {
-			return lhs.R_component_1() == rhs
-				&& lhs.R_component_2() == static_cast<T>(0)
-				&& lhs.R_component_3() == static_cast<T>(0)
-				&& lhs.R_component_4() == static_cast<T>(0)
-				;
-		}
-		template<typename T>
-		inline SPROUT_CONSTEXPR bool
-		operator==(sprout::complex<T> const& lhs, sprout::math::quaternion<T> const& rhs) {
-			return rhs.R_component_1() == lhs.real()
-				&& rhs.R_component_2() == lhs.imag()
-				&& rhs.R_component_3() == static_cast<T>(0)
-				&& rhs.R_component_4() == static_cast<T>(0)
-				;
-		}
-		template<typename T>
-		inline SPROUT_CONSTEXPR bool
-		operator==(sprout::math::quaternion<T> const& lhs, sprout::complex<T> const& rhs) {
-			return lhs.R_component_1() == rhs.real()
-				&& lhs.R_component_2() == rhs.imag()
-				&& lhs.R_component_3() == static_cast<T>(0)
-				&& lhs.R_component_4() == static_cast<T>(0)
-				;
-		}
-		template<typename T>
-		inline SPROUT_CONSTEXPR bool
-		operator==(sprout::math::quaternion<T> const& lhs, sprout::math::quaternion<T> const& rhs) {
-			return rhs.R_component_1() == lhs.R_component_1()
-				&& rhs.R_component_2() == lhs.R_component_2()
-				&& rhs.R_component_3() == lhs.R_component_3()
-				&& rhs.R_component_4() == lhs.R_component_4()
-				;
-		}
-
-#define	SPROUT_QUATERNION_NOT_EQUAL_GENERATOR \
-		{ \
-			return !(lhs == rhs); \
-		}
-
-		template<typename T>
-		inline SPROUT_CONSTEXPR bool
-		operator!=(T const& lhs, sprout::math::quaternion<T> const& rhs)
-		SPROUT_QUATERNION_NOT_EQUAL_GENERATOR
-		template<typename T>
-		inline SPROUT_CONSTEXPR bool
-		operator!=(sprout::math::quaternion<T> const& lhs, T const& rhs)
-		SPROUT_QUATERNION_NOT_EQUAL_GENERATOR
-		template<typename T>
-		inline SPROUT_CONSTEXPR bool
-		operator!=(sprout::complex<T> const& lhs, sprout::math::quaternion<T> const& rhs)
-		SPROUT_QUATERNION_NOT_EQUAL_GENERATOR
-		template<typename T>
-		inline SPROUT_CONSTEXPR bool
-		operator!=(sprout::math::quaternion<T> const& lhs, sprout::complex<T> const& rhs)
-		SPROUT_QUATERNION_NOT_EQUAL_GENERATOR
-		template<typename T>
-		inline SPROUT_CONSTEXPR bool
-		operator!=(sprout::math::quaternion<T> const& lhs, sprout::math::quaternion<T> const& rhs)
-		SPROUT_QUATERNION_NOT_EQUAL_GENERATOR
-
-#undef	SPROUT_QUATERNION_NOT_EQUAL_GENERATOR
-
-		//
-		// operator<<
-		// operator>>
-		//
-		template<typename T, typename Elem, typename Traits>
-		inline SPROUT_NON_CONSTEXPR std::basic_ostream<Elem, Traits>&
-		operator<<(	std::basic_ostream<Elem, Traits>& lhs, sprout::math::quaternion<T> const& rhs) {
-			std::basic_ostringstream<Elem, Traits> s;
-			s.flags(lhs.flags());
-			s.imbue(lhs.getloc());
-			s.precision(lhs.precision());
-			s
-				<< '('
-				<< rhs.R_component_1() << ','
-				<< rhs.R_component_2() << ','
-				<< rhs.R_component_3() << ','
-				<< rhs.R_component_4()
-				<< ')'
-				;
-			return lhs << s.str();
-		}
-		template<typename T, typename Elem, typename Traits>
-		inline SPROUT_NON_CONSTEXPR std::basic_istream<Elem, Traits>&
-		operator>>(std::basic_istream<Elem, Traits>& lhs, sprout::math::quaternion<T>& rhs) {
-			std::ctype<Elem> const& ct = std::use_facet<std::ctype<Elem> >(lhs.getloc());
-			T a = T();
-			T b = T();
-			T c = T();
-			T d = T();
-			sprout::complex<T> u = sprout::complex<T>();
-			sprout::complex<T> v = sprout::complex<T>();
-			Elem ch = Elem();
-			char cc;
-			lhs >> ch;
-			if (!lhs.good()) {
-				goto finish;
-			}
-			cc = ct.narrow(ch, char());
-			if (cc == '(') {
-				lhs >> ch;
-				if (!lhs.good()) {
-					goto finish;
-				}
-				cc = ct.narrow(ch, char());
-				if (cc == '(') {
-					lhs.putback(ch);
-					lhs >> u;
-					a = u.real();
-					b = u.imag();
-					if (!lhs.good()) {
-						goto finish;
-					}
-					lhs >> ch;
-					if (!lhs.good()) {
-						goto finish;
-					}
-					cc = ct.narrow(ch, char());
-					if (cc == ')') {
-						rhs = sprout::math::quaternion<T>(a, b);
-					} else if (cc == ',') {
-						lhs >> v;
-						c = v.real();
-						d = v.imag();
-						if (!lhs.good()) {
-							goto finish;
-						}
-						lhs >> ch;
-						if (!lhs.good()) {
-							goto finish;
-						}
-						cc = ct.narrow(ch, char());
-						if (cc == ')') {
-							rhs = sprout::math::quaternion<T>(a, b, c, d);
-						} else {
-							lhs.setstate(std::ios_base::failbit);
-						}
-					} else {
-						lhs.setstate(std::ios_base::failbit);
-					}
-				} else {
-					lhs.putback(ch);
-					lhs >> a;
-					if (!lhs.good()) {
-						goto finish;
-					}
-					lhs >> ch;
-					if (!lhs.good()) {
-						goto finish;
-					}
-					cc = ct.narrow(ch, char());
-					if (cc == ')') {
-						rhs = sprout::math::quaternion<T>(a);
-					} else if (cc == ',') {
-						lhs >> ch;
-						if (!lhs.good()) {
-							goto finish;
-						}
-						cc = ct.narrow(ch, char());
-						if (cc == '(') {
-							lhs.putback(ch);
-							lhs >> v;
-							c = v.real();
-							d = v.imag();
-							if (!lhs.good()) {
-								goto finish;
-							}
-							lhs >> ch;
-							if (!lhs.good()) {
-								goto finish;
-							}
-							cc = ct.narrow(ch, char());
-							if (cc == ')') {
-								rhs = sprout::math::quaternion<T>(a, b, c, d);
-							} else {
-								lhs.setstate(std::ios_base::failbit);
-							}
-						} else {
-							lhs.putback(ch);
-							lhs >> b;
-							if (!lhs.good()) {
-								goto finish;
-							}
-							lhs >> ch;
-							if (!lhs.good()) {
-								goto finish;
-							}
-							cc = ct.narrow(ch, char());
-							if (cc == ')') {
-								rhs = sprout::math::quaternion<T>(a, b);
-							} else if (cc == ',') {
-								lhs >> c;
-								if (!lhs.good()) {
-									goto finish;
-								}
-								lhs >> ch;
-								if (!lhs.good()) {
-									goto finish;
-								}
-								cc = ct.narrow(ch, char());
-								if (cc == ')') {
-									rhs = sprout::math::quaternion<T>(a, b, c);
-								} else if (cc == ',') {
-									lhs >> d;
-									if (!lhs.good()) {
-										goto finish;
-									}
-									lhs >> ch;
-									if (!lhs.good()) {
-										goto finish;
-									}
-									cc = ct.narrow(ch, char());
-									if (cc == ')') {
-										rhs = sprout::math::quaternion<T>(a, b, c, d);
-									} else {
-										lhs.setstate(std::ios_base::failbit);
-									}
-								} else {
-									lhs.setstate(std::ios_base::failbit);
-								}
-							} else {
-								lhs.setstate(std::ios_base::failbit);
-							}
-						}
-					} else {
-						lhs.setstate(std::ios_base::failbit);
-					}
-				}
-			} else {
-				lhs.putback(ch);
-				lhs >> a;
-				if (!lhs.good()) {
-					goto finish;
-				}
-				rhs = sprout::math::quaternion<T>(a);
-			}
-		finish:
-			return lhs;
-		}
-	}	// namespace math
-}	// namespace sprout
+#include <sprout/math/quaternion/arithmetic_operators.hpp>
+#include <sprout/math/quaternion/stream_operators.hpp>
 
 #endif	// #ifndef SPROUT_MATH_QUATERNION_OPERATORS_HPP
diff --git a/sprout/math/quaternion/stream_operators.hpp b/sprout/math/quaternion/stream_operators.hpp
new file mode 100644
index 00000000..bd42f5e6
--- /dev/null
+++ b/sprout/math/quaternion/stream_operators.hpp
@@ -0,0 +1,200 @@
+/*=============================================================================
+  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_QUATERNION_STREAM_OPERATORS_HPP
+#define SPROUT_MATH_QUATERNION_STREAM_OPERATORS_HPP
+
+#include <iosfwd>
+#include <sstream>
+#include <locale>
+#include <sprout/config.hpp>
+#include <sprout/math/quaternion/quaternion.hpp>
+
+namespace sprout {
+	namespace math {
+		//
+		// operator<<
+		// operator>>
+		//
+		template<typename T, typename Elem, typename Traits>
+		inline SPROUT_NON_CONSTEXPR std::basic_ostream<Elem, Traits>&
+		operator<<(	std::basic_ostream<Elem, Traits>& lhs, sprout::math::quaternion<T> const& rhs) {
+			std::basic_ostringstream<Elem, Traits> s;
+			s.flags(lhs.flags());
+			s.imbue(lhs.getloc());
+			s.precision(lhs.precision());
+			s
+				<< '('
+				<< rhs.R_component_1() << ','
+				<< rhs.R_component_2() << ','
+				<< rhs.R_component_3() << ','
+				<< rhs.R_component_4()
+				<< ')'
+				;
+			return lhs << s.str();
+		}
+		template<typename T, typename Elem, typename Traits>
+		inline SPROUT_NON_CONSTEXPR std::basic_istream<Elem, Traits>&
+		operator>>(std::basic_istream<Elem, Traits>& lhs, sprout::math::quaternion<T>& rhs) {
+			std::ctype<Elem> const& ct = std::use_facet<std::ctype<Elem> >(lhs.getloc());
+			T a = T();
+			T b = T();
+			T c = T();
+			T d = T();
+			sprout::complex<T> u = sprout::complex<T>();
+			sprout::complex<T> v = sprout::complex<T>();
+			Elem ch = Elem();
+			char cc;
+			lhs >> ch;
+			if (!lhs.good()) {
+				goto finish;
+			}
+			cc = ct.narrow(ch, char());
+			if (cc == '(') {
+				lhs >> ch;
+				if (!lhs.good()) {
+					goto finish;
+				}
+				cc = ct.narrow(ch, char());
+				if (cc == '(') {
+					lhs.putback(ch);
+					lhs >> u;
+					a = u.real();
+					b = u.imag();
+					if (!lhs.good()) {
+						goto finish;
+					}
+					lhs >> ch;
+					if (!lhs.good()) {
+						goto finish;
+					}
+					cc = ct.narrow(ch, char());
+					if (cc == ')') {
+						rhs = sprout::math::quaternion<T>(a, b);
+					} else if (cc == ',') {
+						lhs >> v;
+						c = v.real();
+						d = v.imag();
+						if (!lhs.good()) {
+							goto finish;
+						}
+						lhs >> ch;
+						if (!lhs.good()) {
+							goto finish;
+						}
+						cc = ct.narrow(ch, char());
+						if (cc == ')') {
+							rhs = sprout::math::quaternion<T>(a, b, c, d);
+						} else {
+							lhs.setstate(std::ios_base::failbit);
+						}
+					} else {
+						lhs.setstate(std::ios_base::failbit);
+					}
+				} else {
+					lhs.putback(ch);
+					lhs >> a;
+					if (!lhs.good()) {
+						goto finish;
+					}
+					lhs >> ch;
+					if (!lhs.good()) {
+						goto finish;
+					}
+					cc = ct.narrow(ch, char());
+					if (cc == ')') {
+						rhs = sprout::math::quaternion<T>(a);
+					} else if (cc == ',') {
+						lhs >> ch;
+						if (!lhs.good()) {
+							goto finish;
+						}
+						cc = ct.narrow(ch, char());
+						if (cc == '(') {
+							lhs.putback(ch);
+							lhs >> v;
+							c = v.real();
+							d = v.imag();
+							if (!lhs.good()) {
+								goto finish;
+							}
+							lhs >> ch;
+							if (!lhs.good()) {
+								goto finish;
+							}
+							cc = ct.narrow(ch, char());
+							if (cc == ')') {
+								rhs = sprout::math::quaternion<T>(a, b, c, d);
+							} else {
+								lhs.setstate(std::ios_base::failbit);
+							}
+						} else {
+							lhs.putback(ch);
+							lhs >> b;
+							if (!lhs.good()) {
+								goto finish;
+							}
+							lhs >> ch;
+							if (!lhs.good()) {
+								goto finish;
+							}
+							cc = ct.narrow(ch, char());
+							if (cc == ')') {
+								rhs = sprout::math::quaternion<T>(a, b);
+							} else if (cc == ',') {
+								lhs >> c;
+								if (!lhs.good()) {
+									goto finish;
+								}
+								lhs >> ch;
+								if (!lhs.good()) {
+									goto finish;
+								}
+								cc = ct.narrow(ch, char());
+								if (cc == ')') {
+									rhs = sprout::math::quaternion<T>(a, b, c);
+								} else if (cc == ',') {
+									lhs >> d;
+									if (!lhs.good()) {
+										goto finish;
+									}
+									lhs >> ch;
+									if (!lhs.good()) {
+										goto finish;
+									}
+									cc = ct.narrow(ch, char());
+									if (cc == ')') {
+										rhs = sprout::math::quaternion<T>(a, b, c, d);
+									} else {
+										lhs.setstate(std::ios_base::failbit);
+									}
+								} else {
+									lhs.setstate(std::ios_base::failbit);
+								}
+							} else {
+								lhs.setstate(std::ios_base::failbit);
+							}
+						}
+					} else {
+						lhs.setstate(std::ios_base::failbit);
+					}
+				}
+			} else {
+				lhs.putback(ch);
+				lhs >> a;
+				if (!lhs.good()) {
+					goto finish;
+				}
+				rhs = sprout::math::quaternion<T>(a);
+			}
+		finish:
+			return lhs;
+		}
+	}	// namespace math
+}	// namespace sprout
+
+#endif	// #ifndef SPROUT_MATH_QUATERNION_STREAM_OPERATORS_HPP