From 4a345e82591404eedf48b8df11cd7508de0b4af1 Mon Sep 17 00:00:00 2001
From: bolero-MURAKAMI <bolero.murakami@gmail.com>
Date: Thu, 29 Sep 2011 22:46:32 +0900
Subject: [PATCH] =?UTF-8?q?random=20=E6=9B=B4=E6=96=B0?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 sprout/random.hpp                             |   5 +
 .../random/detail/signed_unsigned_tools.hpp   |  63 +++++
 sprout/random/linear_congruential.hpp         |  21 +-
 sprout/random/random_result.hpp               | 127 +++++++++
 sprout/random/uniform_01.hpp                  |  91 +++++++
 sprout/random/uniform_smallint.hpp            | 245 ++++++++++++++++++
 6 files changed, 544 insertions(+), 8 deletions(-)
 create mode 100644 sprout/random/detail/signed_unsigned_tools.hpp
 create mode 100644 sprout/random/random_result.hpp
 create mode 100644 sprout/random/uniform_01.hpp
 create mode 100644 sprout/random/uniform_smallint.hpp

diff --git a/sprout/random.hpp b/sprout/random.hpp
index af3555dd..1a6a9396 100644
--- a/sprout/random.hpp
+++ b/sprout/random.hpp
@@ -1,7 +1,12 @@
 #ifndef SPROUT_RANDOM_HPP
 #define SPROUT_RANDOM_HPP
 
+#include <sprout/config.hpp>
+#include <sprout/random/random_result.hpp>
 #include <sprout/random/linear_congruential.hpp>
+#include <sprout/random/uniform_smallint.hpp>
+#include <sprout/random/uniform_01.hpp>
 
 #endif // #ifndef SPROUT_RANDOM_HPP
 
+
diff --git a/sprout/random/detail/signed_unsigned_tools.hpp b/sprout/random/detail/signed_unsigned_tools.hpp
new file mode 100644
index 00000000..cd8eeb96
--- /dev/null
+++ b/sprout/random/detail/signed_unsigned_tools.hpp
@@ -0,0 +1,63 @@
+#ifndef SPROUT_RANDOM_DETAIL_SIGNED_UNSIGNED_TOOLS_HPP
+#define SPROUT_RANDOM_DETAIL_SIGNED_UNSIGNED_TOOLS_HPP
+
+#include <limits>
+#include <type_traits>
+#include <sprout/config.hpp>
+
+namespace sprout {
+	namespace random {
+		namespace detail {
+			template<typename T, bool B = std::numeric_limits<T>::is_signed>
+			struct subtract {};
+			template<typename T>
+			struct subtract<T, false> {
+			public:
+				typedef T result_type;
+			public:
+				SPROUT_CONSTEXPR result_type operator()(T x, T y) const {
+					return x - y;
+				}
+			};
+			template<typename T>
+			struct subtract<T, true> {
+			public:
+				typedef typename std::make_unsigned<T>::type result_type;
+			public:
+				SPROUT_CONSTEXPR result_type operator()(T x, T y) const {
+					return y >= 0 ? result_type(x) - result_type(y)
+						: x >= 0 ? result_type(x) + result_type(-(y + 1)) + 1
+						: result_type(x - y)
+						;
+				}
+			};
+
+			template<typename T1, typename T2, bool B = std::numeric_limits<T2>::is_signed>
+			struct add {};
+			template<typename T1, typename T2>
+			struct add<T1, T2, false> {
+			public:
+				typedef T2 result_type;
+			public:
+				SPROUT_CONSTEXPR result_type operator()(T1 x, T2 y) const {
+					return T2(x) + y;
+				}
+			};
+			template<typename T1, typename T2>
+			struct add<T1, T2, true> {
+			public:
+				typedef T2 result_type;
+			public:
+				SPROUT_CONSTEXPR result_type operator()(T1 x, T2 y) const {
+					return y >= 0 ? T2(x) + y
+						: x >= T1(-(y + 1)) ? T2(x - T1(-(y + 1)) - 1)
+						: T2(x) + y
+						;
+				}
+			};
+		} // namespace detail
+	} // namespace random
+} // namespace sprout
+
+#endif // SPROUT_RANDOM_DETAIL_SIGNED_UNSIGNED_TOOLS_HPP
+
diff --git a/sprout/random/linear_congruential.hpp b/sprout/random/linear_congruential.hpp
index 655f6eef..ac41ba0f 100644
--- a/sprout/random/linear_congruential.hpp
+++ b/sprout/random/linear_congruential.hpp
@@ -6,6 +6,7 @@
 #include <ios>
 #include <sprout/config.hpp>
 #include <sprout/random/detail/const_mod.hpp>
+#include <sprout/random/random_result.hpp>
 
 namespace sprout {
 	namespace random {
@@ -29,9 +30,10 @@ namespace sprout {
 			static_assert(m == 0 || c < m, "m == 0 || c < m");
 		private:
 			static SPROUT_CONSTEXPR IntType init_seed_3(IntType const& x0) {
-				//static_assert(x0 >= static_min(), "x0 >= static_min()");
-				//static_assert(x0 <= static_max(), "x0 <= static_max()");
-				return x0;
+				return x0 >= static_min() && x0 <= static_max()
+					? x0
+					: throw "assert(x0 >= static_min() && x0 <= static_max())"
+					;
 			}
 			static SPROUT_CONSTEXPR IntType init_seed_2(IntType const& x0) {
 				return init_seed_3(increment == 0 && x0 == 0 ? 1 : x0);
@@ -55,6 +57,12 @@ namespace sprout {
 			SPROUT_CONSTEXPR linear_congruential_engine(IntType const& x, private_constructor_tag)
 				: x_(x)
 			{}
+			SPROUT_CONSTEXPR sprout::random::random_result<linear_congruential_engine> generate(result_type result) const {
+				return sprout::random::random_result<linear_congruential_engine>(
+					result,
+					linear_congruential_engine(result, private_constructor_tag())
+					);
+			}
 		public:
 			SPROUT_CONSTEXPR linear_congruential_engine()
 				: x_(init_seed(default_seed))
@@ -68,11 +76,8 @@ namespace sprout {
 			SPROUT_CONSTEXPR result_type max() const {
 				return static_max();
 			}
-			SPROUT_CONSTEXPR result_type operator()() const {
-				return sprout::random::detail::const_mod<IntType, m>::mult_add(a, x_, c);
-			}
-			SPROUT_CONSTEXPR linear_congruential_engine next() const {
-				return linear_congruential_engine(operator()(), private_constructor_tag());
+			SPROUT_CONSTEXPR sprout::random::random_result<linear_congruential_engine> operator()() const {
+				return generate(sprout::random::detail::const_mod<IntType, m>::mult_add(a, x_, c));
 			}
 			friend SPROUT_CONSTEXPR bool operator==(linear_congruential_engine const& lhs, linear_congruential_engine const& rhs) {
 				return lhs.x_ == rhs.x_;
diff --git a/sprout/random/random_result.hpp b/sprout/random/random_result.hpp
new file mode 100644
index 00000000..99f5e730
--- /dev/null
+++ b/sprout/random/random_result.hpp
@@ -0,0 +1,127 @@
+#ifndef SPROUT_RANDOM_RANDOM_RESULT_HPP
+#define SPROUT_RANDOM_RANDOM_RESULT_HPP
+
+#include <type_traits>
+#include <sprout/config.hpp>
+
+namespace sprout {
+	namespace random {
+		//
+		// random_result
+		//
+		template<typename Engine, typename Distribution = void, typename Enable = void>
+		class random_result;
+
+		template<typename Engine, typename Distribution>
+		class random_result<
+			Engine,
+			Distribution,
+			typename std::enable_if<!std::is_same<Distribution, void>::value>::type
+		> {
+		public:
+			typedef Engine engine_type;
+			typedef Distribution distribution_type;
+			typedef typename distribution_type::result_type result_type;
+		private:
+			result_type result_;
+			engine_type engine_;
+			distribution_type distribution_;
+		public:
+			SPROUT_CONSTEXPR random_result(
+				result_type result,
+				engine_type const& engine,
+				distribution_type const& distribution
+				)
+				: result_(result)
+				, engine_(engine)
+				, distribution_(distribution)
+			{}
+			SPROUT_CONSTEXPR operator result_type() const {
+				return result_;
+			}
+			SPROUT_CONSTEXPR result_type operator*() const {
+				return result_;
+			}
+			SPROUT_CONSTEXPR random_result operator()() const {
+				return distribution_(engine_);
+			}
+			result_type& result() {
+				return result_;
+			}
+			SPROUT_CONSTEXPR result_type const& result() const {
+				return result_;
+			}
+			engine_type& engine() {
+				return engine_;
+			}
+			SPROUT_CONSTEXPR engine_type const& engine() const {
+				return engine_;
+			}
+			distribution_type& distribution() {
+				return distribution_;
+			}
+			SPROUT_CONSTEXPR distribution_type const& distribution() const {
+				return distribution_;
+			}
+			SPROUT_CONSTEXPR result_type min() const {
+				return distribution_.min();
+			}
+			SPROUT_CONSTEXPR result_type max() const {
+				return distribution_.max();
+			}
+		};
+		template<typename Engine, typename Distribution>
+		class random_result<
+			Engine,
+			Distribution,
+			typename std::enable_if<std::is_same<Distribution, void>::value>::type
+		> {
+		public:
+			typedef Engine engine_type;
+			typedef typename engine_type::result_type result_type;
+		private:
+			result_type result_;
+			engine_type engine_;
+		public:
+			SPROUT_CONSTEXPR random_result(
+				result_type result,
+				engine_type const& engine
+				)
+				: result_(result)
+				, engine_(engine)
+			{}
+			SPROUT_CONSTEXPR operator result_type() const {
+				return result_;
+			}
+			SPROUT_CONSTEXPR result_type operator*() const {
+				return result_;
+			}
+			SPROUT_CONSTEXPR random_result operator()() const {
+				return engine_();
+			}
+			result_type& result() {
+				return result_;
+			}
+			SPROUT_CONSTEXPR result_type const& result() const {
+				return result_;
+			}
+			engine_type& engine() {
+				return engine_;
+			}
+			SPROUT_CONSTEXPR engine_type const& engine() const {
+				return engine_;
+			}
+			SPROUT_CONSTEXPR result_type min() const {
+				return engine_.min();
+			}
+			SPROUT_CONSTEXPR result_type max() const {
+				return engine_.max();
+			}
+		};
+	}	// namespace random
+
+	using sprout::random::random_result;
+}	// namespace sprout
+
+#endif // #ifndef SPROUT_RANDOM_RANDOM_RESULT_HPP
+
diff --git a/sprout/random/uniform_01.hpp b/sprout/random/uniform_01.hpp
new file mode 100644
index 00000000..3adc08a6
--- /dev/null
+++ b/sprout/random/uniform_01.hpp
@@ -0,0 +1,91 @@
+#ifndef SPROUT_RANDOM_UNIFORM_01_HPP
+#define SPROUT_RANDOM_UNIFORM_01_HPP
+
+#include <iosfwd>
+#include <limits>
+#include <sprout/config.hpp>
+#include <sprout/random/random_result.hpp>
+
+namespace sprout {
+	namespace random {
+		//
+		// uniform_01
+		//
+		template<typename RealType = double>
+		class uniform_01 {
+		public:
+			typedef RealType input_type;
+			typedef RealType result_type;
+		private:
+			template<typename Engine>
+			SPROUT_CONSTEXPR sprout::random::random_result<Engine, uniform_01> generate_1(
+				Engine const& eng,
+				sprout::random::random_result<Engine> const& rnd,
+				result_type result
+				) const
+			{
+				return result < result_type(1)
+					? sprout::random::random_result<Engine, uniform_01>(result, rnd.engine(), *this)
+					: operator()(rnd.engine())
+					;
+			}
+			template<typename Engine>
+			SPROUT_CONSTEXPR sprout::random::random_result<Engine, uniform_01> generate(
+				Engine const& eng,
+				sprout::random::random_result<Engine> const& rnd
+				) const
+			{
+				typedef typename Engine::result_type base_result;
+				return generate_1(
+					eng,
+					rnd,
+					result_type(rnd.result() - eng.min()) * (
+						result_type(1) / (
+							result_type(eng.max() - eng.min()) + result_type(
+								std::numeric_limits<base_result>::is_integer ? 1 : 0
+								)
+							)
+						)
+					);
+			}
+		public:
+			SPROUT_CONSTEXPR result_type min() const {
+				return result_type(0);
+			}
+			SPROUT_CONSTEXPR result_type max() const {
+				return result_type(1);
+			}
+			template<typename Engine>
+			SPROUT_CONSTEXPR sprout::random::random_result<Engine, uniform_01> operator()(Engine const& eng) const {
+				return generate(eng, eng());
+			}
+			template<typename Elem, typename Traits>
+			friend std::basic_ostream<Elem, Traits>& operator>>(
+				std::basic_istream<Elem, Traits>& lhs,
+				uniform_01 const& rhs
+				)
+			{
+				return lhs;
+			}
+			template<typename Elem, typename Traits>
+			friend std::basic_ostream<Elem, Traits>& operator<<(
+				std::basic_ostream<Elem, Traits>& lhs,
+				uniform_01 const& rhs
+				)
+			{
+				return lhs;
+			}
+			SPROUT_CONSTEXPR friend bool operator==(uniform_01 const& lhs, uniform_01 const& rhs) {
+				return true;
+			}
+			SPROUT_CONSTEXPR friend bool operator!=(uniform_01 const& lhs, uniform_01 const& rhs) {
+				return !(lhs == rhs);
+			}
+		};
+	}	// namespace random
+
+	using sprout::random::uniform_01;
+}	// namespace sprout
+
+#endif // #ifndef SPROUT_RANDOM_UNIFORM_01_HPP
+
diff --git a/sprout/random/uniform_smallint.hpp b/sprout/random/uniform_smallint.hpp
new file mode 100644
index 00000000..92e6ea51
--- /dev/null
+++ b/sprout/random/uniform_smallint.hpp
@@ -0,0 +1,245 @@
+#ifndef SPROUT_RANDOM_UNIFORM_SMALLINT_HPP
+#define SPROUT_RANDOM_UNIFORM_SMALLINT_HPP
+
+#include <iosfwd>
+#include <istream>
+#include <type_traits>
+#include <sprout/config.hpp>
+#include <sprout/random/detail/signed_unsigned_tools.hpp>
+#include <sprout/random/random_result.hpp>
+#include <sprout/random/uniform_01.hpp>
+
+namespace sprout {
+	namespace random {
+		//
+		// uniform_smallint
+		//
+		template<typename IntType = int>
+		class uniform_smallint {
+		public:
+			typedef IntType input_type;
+			typedef IntType result_type;
+		public:
+			//
+			// param_type
+			//
+			class param_type {
+			public:
+				typedef uniform_smallint distribution_type;
+			private:
+				static SPROUT_CONSTEXPR IntType arg_check(IntType min_arg, IntType max_arg) {
+					return min_arg <= max_arg
+						? min_arg
+						: throw "assert(min_arg <= max_arg)"
+						;
+				}
+			private:
+				IntType min_;
+				IntType max_;
+			public:
+				SPROUT_CONSTEXPR param_type(IntType min_arg = 0, IntType max_arg = 9)
+					: min_(arg_check(min_arg, max_arg))
+					, max_(max_arg)
+				{}
+				SPROUT_CONSTEXPR IntType a() const {
+					return min_;
+				}
+				SPROUT_CONSTEXPR IntType b() const {
+					return max_;
+				}
+				template<typename Elem, typename Traits>
+				friend std::basic_ostream<Elem, Traits>& operator>>(
+					std::basic_istream<Elem, Traits>& lhs,
+					param_type const& rhs
+					)
+				{
+					return lhs >> rhs.min_ >> std::ws >> rhs.max_;
+				}
+				template<typename Elem, typename Traits>
+				friend std::basic_ostream<Elem, Traits>& operator<<(
+					std::basic_ostream<Elem, Traits>& lhs,
+					param_type const& rhs
+					)
+				{
+					return lhs << rhs.min_ << " " << rhs.max_;
+				}
+				SPROUT_CONSTEXPR friend bool operator==(param_type const& lhs, param_type const& rhs) {
+					return lhs.min_ == rhs.min_ && lhs.max_ == rhs.max_;
+				}
+				SPROUT_CONSTEXPR friend bool operator!=(param_type const& lhs, param_type const& rhs) {
+					return !(lhs == rhs);
+				}
+			};
+		private:
+			result_type min_;
+			result_type max_;
+		private:
+			template<typename Engine, typename RangeType, typename BaseUnsigned>
+			SPROUT_CONSTEXPR sprout::random::random_result<Engine, uniform_smallint> generate_true_2(
+				Engine const& eng,
+				sprout::random::random_result<Engine> const& rnd,
+				RangeType range,
+				BaseUnsigned base_range,
+				BaseUnsigned val
+				) const
+			{
+				return range >= base_range
+					? sprout::random::random_result<Engine, uniform_smallint>(
+						sprout::random::detail::add<RangeType, result_type>()(static_cast<RangeType>(val), min_),
+						rnd.engine(),
+						*this
+						)
+					: sprout::random::random_result<Engine, uniform_smallint>(
+						sprout::random::detail::add<RangeType, result_type>()(static_cast<RangeType>(val % (static_cast<BaseUnsigned>(range) + 1)), min_),
+						rnd.engine(),
+						*this
+						)
+					;
+			}
+			template<typename Engine, typename RangeType, typename BaseUnsigned>
+			SPROUT_CONSTEXPR sprout::random::random_result<Engine, uniform_smallint> generate_true_1(
+				Engine const& eng,
+				sprout::random::random_result<Engine> const& rnd,
+				RangeType range,
+				BaseUnsigned base_range
+				) const
+			{
+				typedef typename Engine::result_type base_result;
+				return generate_true_2(
+					eng,
+					rnd,
+					range,
+					base_range,
+					BaseUnsigned(sprout::random::detail::subtract<base_result>()(rnd.result(), eng.min()))
+					);
+			}
+			template<typename Engine>
+			SPROUT_CONSTEXPR sprout::random::random_result<Engine, uniform_smallint> generate(
+				Engine const& eng,
+				std::true_type
+				) const
+			{
+				typedef typename Engine::result_type base_result;
+				typedef typename std::make_unsigned<base_result>::type base_unsigned;
+				typedef typename std::make_unsigned<result_type>::type range_type;
+				return generate_true_1(
+					eng,
+					eng(),
+					range_type(sprout::random::detail::subtract<result_type>()(max_, min_)),
+					base_unsigned(sprout::random::detail::subtract<result_type>()(eng.max(), eng.min()))
+					);
+			}
+			template<typename Engine, typename RangeType>
+			SPROUT_CONSTEXPR sprout::random::random_result<Engine, uniform_smallint> generate_false_2(
+				Engine const& eng,
+				sprout::random::random_result<Engine, sprout::random::uniform_01<typename Engine::result_type> > const& rnd,
+				RangeType range,
+				RangeType offset
+				) const
+			{
+				return offset > range
+					? sprout::random::random_result<Engine, uniform_smallint>(
+						max_,
+						rnd.engine(),
+						*this
+						)
+					: sprout::random::random_result<Engine, uniform_smallint>(
+						sprout::random::detail::add<RangeType, result_type>()(offset , min_),
+						rnd.engine(),
+						*this
+						)
+					;
+			}
+			template<typename Engine, typename RangeType>
+			SPROUT_CONSTEXPR sprout::random::random_result<Engine, uniform_smallint> generate_false_1(
+				Engine const& eng,
+				sprout::random::random_result<Engine, sprout::random::uniform_01<typename Engine::result_type> > const& rnd,
+				RangeType range
+				) const
+			{
+				typedef typename Engine::result_type base_result;
+				return generate_false_2(
+					eng,
+					rnd,
+					RangeType(sprout::random::detail::subtract<result_type>()(max_, min_)),
+					RangeType(static_cast<RangeType>(rnd.result() * (static_cast<base_result>(range) + 1)))
+					);
+			}
+			template<class Engine>
+			SPROUT_CONSTEXPR sprout::random::random_result<Engine, uniform_smallint> generate(
+				Engine const& eng,
+				std::false_type
+				) const
+			{
+				typedef typename Engine::result_type base_result;
+				typedef typename std::make_unsigned<result_type>::type range_type;
+				return generate_false_1(
+					eng,
+					sprout::random::uniform_01<base_result>()(eng),
+					range_type(sprout::random::detail::subtract<result_type>()(max_, min_))
+					);
+			}
+		public:
+			SPROUT_CONSTEXPR explicit uniform_smallint(IntType min_arg = 0, IntType max_arg = 9)
+				: min_(min_arg), max_(max_arg)
+			{}
+			explicit uniform_smallint(param_type const& parm)
+				: min_(parm.a()), max_(parm.b())
+			{}
+			SPROUT_CONSTEXPR result_type a() const {
+				return min_;
+			}
+			SPROUT_CONSTEXPR result_type b() const {
+				return max_;
+			}
+			SPROUT_CONSTEXPR result_type min() const {
+				return min_;
+			}
+			SPROUT_CONSTEXPR result_type max() const {
+				return max_;
+			}
+			SPROUT_CONSTEXPR param_type param() const {
+				return param_type(min_, max_);
+			}
+			void param(param_type const& parm) {
+				min_ = parm.a();
+				max_ = parm.b();
+			}
+			template<typename Engine>
+			SPROUT_CONSTEXPR sprout::random::random_result<Engine, uniform_smallint> operator()(Engine const& eng) const {
+				typedef typename Engine::result_type base_result;
+				return generate(eng, typename std::is_integral<base_result>::type());
+			}
+			template<typename Elem, typename Traits>
+			friend std::basic_ostream<Elem, Traits>& operator>>(
+				std::basic_istream<Elem, Traits>& lhs,
+				uniform_smallint const& rhs
+				)
+			{
+				param_type parm;
+				return lhs >> parm;
+				param(parm);
+				return lhs;
+			}
+			template<typename Elem, typename Traits>
+			friend std::basic_ostream<Elem, Traits>& operator<<(
+				std::basic_ostream<Elem, Traits>& lhs,
+				uniform_smallint const& rhs
+				)
+			{
+				return lhs << param();
+			}
+			SPROUT_CONSTEXPR friend bool operator==(uniform_smallint const& lhs, uniform_smallint const& rhs) {
+				return lhs.param() == rhs.param();
+			}
+			SPROUT_CONSTEXPR friend bool operator!=(uniform_smallint const& lhs, uniform_smallint const& rhs) {
+				return !(lhs == rhs);
+			}
+		};
+	}	// namespace random
+
+	using sprout::random::uniform_smallint;
+}	// namespace sprout
+
+#endif // #ifndef SPROUT_RANDOM_UNIFORM_SMALLINT_HPP
+