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Sprout/sprout/random/uniform_real_distribution.hpp
2014-01-17 22:09:08 +09:00

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/*=============================================================================
Copyright (c) 2011-2014 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_RANDOM_UNIFORM_REAL_DISTRIBUTION_HPP
#define SPROUT_RANDOM_UNIFORM_REAL_DISTRIBUTION_HPP
#include <ios>
#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/results.hpp>
#include <sprout/assert.hpp>
namespace sprout {
namespace random {
namespace detail {
template<typename T, typename Engine>
struct generate_uniform_real_result {
public:
T result;
Engine engine;
};
template<typename Engine, typename T>
inline SPROUT_CXX14_CONSTEXPR T
generate_uniform_real(
Engine& eng, T min_value, T max_value,
std::false_type
)
{
for(;;) {
typedef T result_type;
typedef typename Engine::result_type base_result;
result_type numerator = static_cast<T>(static_cast<base_result>(eng()) - eng.min());
result_type divisor = static_cast<T>(eng.max() - eng.min());
SPROUT_ASSERT(divisor > 0);
SPROUT_ASSERT(numerator >= 0 && numerator <= divisor);
result_type result = numerator / divisor * (max_value - min_value) + min_value;
if (result < max_value) {
return result;
}
}
}
template<typename Engine, typename T>
inline SPROUT_CXX14_CONSTEXPR T
generate_uniform_real(
Engine& eng, T min_value, T max_value,
std::true_type
)
{
for(;;) {
typedef T result_type;
typedef typename Engine::result_type base_result;
result_type numerator = static_cast<T>(sprout::random::detail::subtract<base_result>()(static_cast<base_result>(eng()), eng.min()));
result_type divisor = static_cast<T>(sprout::random::detail::subtract<base_result>()(eng.max(), eng.min())) + 1;
SPROUT_ASSERT(divisor > 0);
SPROUT_ASSERT(numerator >= 0 && numerator <= divisor);
result_type result = numerator / divisor * (max_value - min_value) + min_value;
if (result < max_value) {
return result;
}
}
}
template<typename Engine, typename T>
inline SPROUT_CXX14_CONSTEXPR T
generate_uniform_real(
Engine& eng, T min_value, T max_value
)
{
return sprout::random::detail::generate_uniform_real(
eng, min_value, max_value,
typename std::is_integral<typename Engine::result_type>::type()
);
}
#ifdef SPROUT_WORKAROUND_NOT_TERMINATE_RECURSIVE_CONSTEXPR_FUNCTION_TEMPLATE
template<int D = 16, typename EngineResult, typename T, SPROUT_RECURSIVE_FUNCTION_TEMPLATE_CONTINUE(D)>
inline SPROUT_CONSTEXPR sprout::random::detail::generate_uniform_real_result<T, typename EngineResult::engine_type>
generate_uniform_real_false_1(
EngineResult const& rnd,
T min_value, T max_value
);
template<int D = 16, typename EngineResult, typename T, SPROUT_RECURSIVE_FUNCTION_TEMPLATE_BREAK(D)>
inline SPROUT_CONSTEXPR sprout::random::detail::generate_uniform_real_result<T, typename EngineResult::engine_type>
generate_uniform_real_false_1(
EngineResult const& rnd,
T min_value, T max_value
);
template<int D, typename Engine, typename T, SPROUT_RECURSIVE_FUNCTION_TEMPLATE_CONTINUE(D)>
inline SPROUT_CONSTEXPR sprout::random::detail::generate_uniform_real_result<T, Engine>
generate_uniform_real_false_3(
Engine const& eng,
T min_value, T max_value,
T result
)
{
return result < max_value
? sprout::random::detail::generate_uniform_real_result<T, Engine>{result, eng}
: sprout::random::detail::generate_uniform_real_false_1<D + 1>(eng(), min_value, max_value)
;
}
template<int D, typename Engine, typename T, SPROUT_RECURSIVE_FUNCTION_TEMPLATE_BREAK(D)>
inline SPROUT_CONSTEXPR sprout::random::detail::generate_uniform_real_result<T, Engine>
generate_uniform_real_false_3(
Engine const&,
T, T,
T
)
{
return sprout::throw_recursive_function_template_instantiation_exeeded();
}
template<int D, typename Engine, typename T, SPROUT_RECURSIVE_FUNCTION_TEMPLATE_CONTINUE(D)>
inline SPROUT_CONSTEXPR sprout::random::detail::generate_uniform_real_result<T, Engine>
generate_uniform_real_false_2(
Engine const& eng,
T min_value, T max_value,
T numerator, T divisor
)
{
return SPROUT_ASSERT(divisor > 0), SPROUT_ASSERT(numerator >= 0 && numerator <= divisor),
sprout::random::detail::generate_uniform_real_false_3<D + 1>(
eng,
min_value, max_value,
numerator / divisor * (max_value - min_value) + min_value
)
;
}
template<int D, typename Engine, typename T, SPROUT_RECURSIVE_FUNCTION_TEMPLATE_BREAK(D)>
inline SPROUT_CONSTEXPR sprout::random::detail::generate_uniform_real_result<T, Engine>
generate_uniform_real_false_2(
Engine const&,
T, T,
T, T
)
{
return sprout::throw_recursive_function_template_instantiation_exeeded();
}
template<int D, typename EngineResult, typename T, SPROUT_RECURSIVE_FUNCTION_TEMPLATE_CONTINUE_DECL(D)>
inline SPROUT_CONSTEXPR sprout::random::detail::generate_uniform_real_result<T, typename EngineResult::engine_type>
generate_uniform_real_false_1(
EngineResult const& rnd,
T min_value, T max_value
)
{
return sprout::random::detail::generate_uniform_real_false_2<D + 1>(
sprout::random::next(rnd),
min_value, max_value,
static_cast<T>(sprout::random::result(rnd) - sprout::random::next(rnd).min()),
static_cast<T>(sprout::random::next(rnd).max() - sprout::random::next(rnd).min())
);
}
template<int D, typename EngineResult, typename T, SPROUT_RECURSIVE_FUNCTION_TEMPLATE_BREAK_DECL(D)>
inline SPROUT_CONSTEXPR sprout::random::detail::generate_uniform_real_result<T, typename EngineResult::engine_type>
generate_uniform_real_false_1(
EngineResult const&,
T, T
)
{
return sprout::throw_recursive_function_template_instantiation_exeeded();
}
template<int D = 16, typename EngineResult, typename T, SPROUT_RECURSIVE_FUNCTION_TEMPLATE_CONTINUE(D)>
inline SPROUT_CONSTEXPR sprout::random::detail::generate_uniform_real_result<T, typename EngineResult::engine_type>
generate_uniform_real_true_1(
EngineResult const& rnd,
T min_value, T max_value
);
template<int D = 16, typename EngineResult, typename T, SPROUT_RECURSIVE_FUNCTION_TEMPLATE_BREAK(D)>
inline SPROUT_CONSTEXPR sprout::random::detail::generate_uniform_real_result<T, typename EngineResult::engine_type>
generate_uniform_real_true_1(
EngineResult const& rnd,
T min_value, T max_value
);
template<int D, typename Engine, typename T, SPROUT_RECURSIVE_FUNCTION_TEMPLATE_CONTINUE(D)>
inline SPROUT_CONSTEXPR sprout::random::detail::generate_uniform_real_result<T, Engine>
generate_uniform_real_true_3(
Engine const& eng,
T min_value, T max_value,
T result
)
{
return result < max_value
? sprout::random::detail::generate_uniform_real_result<T, Engine>{result, eng}
: sprout::random::detail::generate_uniform_real_true_1<D + 1>(eng(), min_value, max_value)
;
}
template<int D, typename Engine, typename T, SPROUT_RECURSIVE_FUNCTION_TEMPLATE_BREAK(D)>
inline SPROUT_CONSTEXPR sprout::random::detail::generate_uniform_real_result<T, Engine>
generate_uniform_real_true_3(
Engine const&,
T, T,
T
)
{
return sprout::throw_recursive_function_template_instantiation_exeeded();
}
template<int D, typename Engine, typename T, SPROUT_RECURSIVE_FUNCTION_TEMPLATE_CONTINUE(D)>
inline SPROUT_CONSTEXPR sprout::random::detail::generate_uniform_real_result<T, Engine>
generate_uniform_real_true_2(
Engine const& eng,
T min_value, T max_value,
T numerator, T divisor
)
{
return SPROUT_ASSERT(divisor > 0), SPROUT_ASSERT(numerator >= 0 && numerator <= divisor),
sprout::random::detail::generate_uniform_real_true_3<D + 1>(
eng,
min_value, max_value,
numerator / divisor * (max_value - min_value) + min_value
)
;
}
template<int D, typename Engine, typename T, SPROUT_RECURSIVE_FUNCTION_TEMPLATE_BREAK(D)>
inline SPROUT_CONSTEXPR sprout::random::detail::generate_uniform_real_result<T, Engine>
generate_uniform_real_true_2(
Engine const&,
T, T,
T, T
)
{
return sprout::throw_recursive_function_template_instantiation_exeeded();
}
template<int D, typename EngineResult, typename T, SPROUT_RECURSIVE_FUNCTION_TEMPLATE_CONTINUE_DECL(D)>
inline SPROUT_CONSTEXPR sprout::random::detail::generate_uniform_real_result<T, typename EngineResult::engine_type>
generate_uniform_real_true_1(
EngineResult const& rnd,
T min_value, T max_value
)
{
typedef typename EngineResult::result_type base_result;
return sprout::random::detail::generate_uniform_real_true_2<D + 1>(
sprout::random::next(rnd),
min_value, max_value,
static_cast<T>(sprout::random::detail::subtract<base_result>()(sprout::random::result(rnd), sprout::random::next(rnd).min())),
static_cast<T>(sprout::random::detail::subtract<base_result>()(sprout::random::next(rnd).max(), sprout::random::next(rnd).min())) + 1
);
}
template<int D, typename EngineResult, typename T, SPROUT_RECURSIVE_FUNCTION_TEMPLATE_BREAK_DECL(D)>
inline SPROUT_CONSTEXPR sprout::random::detail::generate_uniform_real_result<T, typename EngineResult::engine_type>
generate_uniform_real_true_1(
EngineResult const&,
T, T
)
{
return sprout::throw_recursive_function_template_instantiation_exeeded();
}
#else
template<typename EngineResult, typename T>
inline SPROUT_CONSTEXPR sprout::random::detail::generate_uniform_real_result<T, typename EngineResult::engine_type>
generate_uniform_real_false_1(
EngineResult const& rnd,
T min_value, T max_value
);
template<typename Engine, typename T>
inline SPROUT_CONSTEXPR sprout::random::detail::generate_uniform_real_result<T, Engine>
generate_uniform_real_false_3(
Engine const& eng,
T min_value, T max_value,
T result
)
{
return result < max_value
? sprout::random::detail::generate_uniform_real_result<T, Engine>{result, eng}
: sprout::random::detail::generate_uniform_real_false_1(eng(), min_value, max_value)
;
}
template<typename Engine, typename T>
inline SPROUT_CONSTEXPR sprout::random::detail::generate_uniform_real_result<T, Engine>
generate_uniform_real_false_2(
Engine const& eng,
T min_value, T max_value,
T numerator, T divisor
)
{
return SPROUT_ASSERT(divisor > 0), SPROUT_ASSERT(numerator >= 0 && numerator <= divisor),
sprout::random::detail::generate_uniform_real_false_3(
eng,
min_value, max_value,
numerator / divisor * (max_value - min_value) + min_value
)
;
}
template<typename EngineResult, typename T>
inline SPROUT_CONSTEXPR sprout::random::detail::generate_uniform_real_result<T, typename EngineResult::engine_type>
generate_uniform_real_false_1(
EngineResult const& rnd,
T min_value, T max_value
)
{
return sprout::random::detail::generate_uniform_real_false_2(
sprout::random::next(rnd),
min_value, max_value,
static_cast<T>(sprout::random::result(rnd) - sprout::random::next(rnd).min()),
static_cast<T>(sprout::random::next(rnd).max() - sprout::random::next(rnd).min())
);
}
template<typename EngineResult, typename T>
inline SPROUT_CONSTEXPR sprout::random::detail::generate_uniform_real_result<T, typename EngineResult::engine_type>
generate_uniform_real_true_1(
EngineResult const& rnd,
T min_value, T max_value
);
template<typename Engine, typename T>
inline SPROUT_CONSTEXPR sprout::random::detail::generate_uniform_real_result<T, Engine>
generate_uniform_real_true_3(
Engine const& eng,
T min_value, T max_value,
T result
)
{
return result < max_value
? sprout::random::detail::generate_uniform_real_result<T, Engine>{result, eng}
: sprout::random::detail::generate_uniform_real_true_1(eng(), min_value, max_value)
;
}
template<typename Engine, typename T>
inline SPROUT_CONSTEXPR sprout::random::detail::generate_uniform_real_result<T, Engine>
generate_uniform_real_true_2(
Engine const& eng,
T min_value, T max_value,
T numerator, T divisor
)
{
return SPROUT_ASSERT(divisor > 0), SPROUT_ASSERT(numerator >= 0 && numerator <= divisor),
sprout::random::detail::generate_uniform_real_true_3(
eng,
min_value, max_value,
numerator / divisor * (max_value - min_value) + min_value
)
;
}
template<typename EngineResult, typename T>
inline SPROUT_CONSTEXPR sprout::random::detail::generate_uniform_real_result<T, typename EngineResult::engine_type>
generate_uniform_real_true_1(
EngineResult const& rnd,
T min_value, T max_value
)
{
typedef typename EngineResult::result_type base_result;
return sprout::random::detail::generate_uniform_real_true_2(
sprout::random::next(rnd),
min_value, max_value,
static_cast<T>(sprout::random::detail::subtract<base_result>()(sprout::random::result(rnd), sprout::random::next(rnd).min())),
static_cast<T>(sprout::random::detail::subtract<base_result>()(sprout::random::next(rnd).max(), sprout::random::next(rnd).min())) + 1
);
}
#endif
template<typename Engine, typename T>
inline SPROUT_CONSTEXPR sprout::random::detail::generate_uniform_real_result<T, Engine>
generate_uniform_real(
Engine const& eng,
T min_value, T max_value,
std::false_type
)
{
return sprout::random::detail::generate_uniform_real_false_1(
eng(),
min_value, max_value
);
}
template<typename Engine, typename T>
inline SPROUT_CONSTEXPR sprout::random::detail::generate_uniform_real_result<T, Engine>
generate_uniform_real(
Engine const& eng,
T min_value, T max_value,
std::true_type
)
{
return sprout::random::detail::generate_uniform_real_true_1(
eng(),
min_value, max_value
);
}
template<typename Engine, typename T>
inline SPROUT_CONSTEXPR sprout::random::detail::generate_uniform_real_result<T, Engine>
generate_uniform_real(
Engine const& eng,
T min_value, T max_value
)
{
return sprout::random::detail::generate_uniform_real(
eng,
min_value, max_value,
typename std::is_integral<typename Engine::result_type>::type()
);
}
} // namespace detail
//
// uniform_real_distribution
//
template<typename RealType = double>
class uniform_real_distribution {
public:
typedef RealType input_type;
typedef RealType result_type;
public:
//
// param_type
//
class param_type {
public:
typedef uniform_real_distribution distribution_type;
private:
RealType min_;
RealType max_;
public:
SPROUT_CONSTEXPR param_type()
: min_(RealType(0.0))
, max_(RealType(1.0))
{}
explicit SPROUT_CONSTEXPR param_type(RealType min_arg, RealType max_arg = RealType(1.0))
: min_((SPROUT_ASSERT(min_arg <= max_arg), min_arg))
, max_(max_arg)
{}
SPROUT_CONSTEXPR RealType a() const SPROUT_NOEXCEPT {
return min_;
}
SPROUT_CONSTEXPR RealType b() const SPROUT_NOEXCEPT {
return max_;
}
template<typename Elem, typename Traits>
friend SPROUT_NON_CONSTEXPR std::basic_istream<Elem, Traits>& operator>>(
std::basic_istream<Elem, Traits>& lhs,
param_type& rhs
)
{
RealType min;
RealType max;
if (lhs >> min >> std::ws >> max) {
if (min <= max) {
rhs.min_ = min;
rhs.max_ = max;
} else {
lhs.setstate(std::ios_base::failbit);
}
}
return lhs;
}
template<typename Elem, typename Traits>
friend SPROUT_NON_CONSTEXPR std::basic_ostream<Elem, Traits>& operator<<(
std::basic_ostream<Elem, Traits>& lhs,
param_type const& rhs
)
{
return lhs << rhs.min_ << " " << rhs.max_;
}
friend SPROUT_CONSTEXPR bool operator==(param_type const& lhs, param_type const& rhs) SPROUT_NOEXCEPT {
return lhs.min_ == rhs.min_ && lhs.max_ == rhs.max_;
}
friend SPROUT_CONSTEXPR bool operator!=(param_type const& lhs, param_type const& rhs) SPROUT_NOEXCEPT {
return !(lhs == rhs);
}
};
private:
RealType min_;
RealType max_;
private:
template<typename Engine, typename Result>
SPROUT_CONSTEXPR sprout::random::random_result<Engine, uniform_real_distribution> generate(Result const& rnd) const {
return sprout::random::random_result<Engine, uniform_real_distribution>(
rnd.result,
rnd.engine,
*this
);
}
public:
SPROUT_CONSTEXPR uniform_real_distribution() SPROUT_NOEXCEPT
: min_(RealType(0.0))
, max_(RealType(1.0))
{}
explicit SPROUT_CONSTEXPR uniform_real_distribution(RealType min_arg, RealType max_arg = RealType(1.0))
: min_((SPROUT_ASSERT(min_arg <= max_arg), min_arg))
, max_(max_arg)
{}
explicit SPROUT_CONSTEXPR uniform_real_distribution(param_type const& parm) SPROUT_NOEXCEPT
: min_(parm.a())
, max_(parm.b())
{}
SPROUT_CONSTEXPR result_type a() const SPROUT_NOEXCEPT {
return min_;
}
SPROUT_CONSTEXPR result_type b() const SPROUT_NOEXCEPT {
return max_;
}
SPROUT_CONSTEXPR result_type min() const SPROUT_NOEXCEPT {
return min_;
}
SPROUT_CONSTEXPR result_type max() const SPROUT_NOEXCEPT {
return max_;
}
SPROUT_CXX14_CONSTEXPR void reset() SPROUT_NOEXCEPT {}
SPROUT_CONSTEXPR param_type param() const SPROUT_NOEXCEPT {
return param_type(min_, max_);
}
SPROUT_CXX14_CONSTEXPR void param(param_type const& parm) {
min_ = parm.a();
max_ = parm.b();
}
template<typename Engine>
SPROUT_CXX14_CONSTEXPR result_type operator()(Engine& eng) const {
return sprout::random::detail::generate_uniform_real(eng, min_, max_);
}
template<typename Engine>
SPROUT_CONSTEXPR sprout::random::random_result<Engine, uniform_real_distribution> const operator()(Engine const& eng) const {
return generate<Engine>(sprout::random::detail::generate_uniform_real(eng, min_, max_));
}
template<typename Engine>
SPROUT_CXX14_CONSTEXPR result_type operator()(Engine& eng, param_type const& parm) const {
return sprout::random::detail::generate_uniform_real(eng, parm.a(), parm.b());
}
template<typename Engine>
SPROUT_CONSTEXPR sprout::random::random_result<Engine, uniform_real_distribution> const operator()(Engine const& eng, param_type const& parm) const {
return generate<Engine>(sprout::random::detail::generate_uniform_real(eng, parm.a(), parm.b()));
}
template<typename Elem, typename Traits>
friend SPROUT_NON_CONSTEXPR std::basic_istream<Elem, Traits>& operator>>(
std::basic_istream<Elem, Traits>& lhs,
uniform_real_distribution& rhs
)
{
param_type parm;
if (lhs >> parm) {
rhs.param(parm);
}
return lhs;
}
template<typename Elem, typename Traits>
friend SPROUT_NON_CONSTEXPR std::basic_ostream<Elem, Traits>& operator<<(
std::basic_ostream<Elem, Traits>& lhs,
uniform_real_distribution const& rhs
)
{
return lhs << rhs.param();
}
friend SPROUT_CONSTEXPR bool operator==(uniform_real_distribution const& lhs, uniform_real_distribution const& rhs) SPROUT_NOEXCEPT {
return lhs.param() == rhs.param();
}
friend SPROUT_CONSTEXPR bool operator!=(uniform_real_distribution const& lhs, uniform_real_distribution const& rhs) SPROUT_NOEXCEPT {
return !(lhs == rhs);
}
};
} // namespace random
using sprout::random::uniform_real_distribution;
} // namespace sprout
#endif // #ifndef SPROUT_RANDOM_UNIFORM_REAL_DISTRIBUTION_HPP