mirror of
https://github.com/bolero-MURAKAMI/Sprout.git
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195 lines
7.1 KiB
C++
195 lines
7.1 KiB
C++
/*=============================================================================
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Copyright (c) 2011-2016 Bolero MURAKAMI
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https://github.com/bolero-MURAKAMI/Sprout
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Distributed under the Boost Software License, Version 1.0. (See accompanying
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file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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=============================================================================*/
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#ifndef SPROUT_RANDOM_UNIFORM_01_HPP
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#define SPROUT_RANDOM_UNIFORM_01_HPP
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#include <iosfwd>
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#include <istream>
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#include <sprout/config.hpp>
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#include <sprout/limits.hpp>
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#include <sprout/random/random_result.hpp>
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#include <sprout/random/results.hpp>
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#ifdef SPROUT_WORKAROUND_NOT_TERMINATE_RECURSIVE_CONSTEXPR_FUNCTION_TEMPLATE
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# include <sprout/workaround/recursive_function_template.hpp>
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#endif
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namespace sprout {
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namespace random {
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//
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// uniform_01
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//
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template<typename RealType = double>
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class uniform_01 {
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public:
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typedef RealType input_type;
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typedef RealType result_type;
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public:
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//
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// param_type
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//
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class param_type {
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public:
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typedef uniform_01 distribution_type;
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public:
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template<typename Elem, typename Traits>
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friend SPROUT_NON_CONSTEXPR std::basic_istream<Elem, Traits>& operator>>(
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std::basic_istream<Elem, Traits>& lhs,
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param_type&
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)
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{
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return lhs;
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}
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template<typename Elem, typename Traits>
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friend SPROUT_NON_CONSTEXPR std::basic_ostream<Elem, Traits>& operator<<(
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std::basic_ostream<Elem, Traits>& lhs,
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param_type const&
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)
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{
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return lhs;
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}
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friend SPROUT_CONSTEXPR bool operator==(param_type const&, param_type const&) SPROUT_NOEXCEPT {
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return true;
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}
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friend SPROUT_CONSTEXPR bool operator!=(param_type const& lhs, param_type const& rhs) SPROUT_NOEXCEPT {
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return !(lhs == rhs);
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}
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};
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private:
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#ifdef SPROUT_WORKAROUND_NOT_TERMINATE_RECURSIVE_CONSTEXPR_FUNCTION_TEMPLATE
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template<int D, typename Engine, typename EngineResult, SPROUT_RECURSIVE_FUNCTION_TEMPLATE_CONTINUE(D)>
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SPROUT_CONSTEXPR sprout::random::random_result<Engine, uniform_01>
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generate_1(Engine const&, EngineResult const& rnd, result_type result) const {
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return result < result_type(1)
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? sprout::random::random_result<Engine, uniform_01>(result, rnd.engine(), *this)
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: generate<D + 1>(sprout::random::next(rnd), sprout::random::next(rnd)())
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;
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}
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template<int D, typename Engine, typename EngineResult, SPROUT_RECURSIVE_FUNCTION_TEMPLATE_BREAK(D)>
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SPROUT_CONSTEXPR sprout::random::random_result<Engine, uniform_01>
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generate_1(Engine const&, EngineResult const&, result_type) const {
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return sprout::throw_recursive_function_template_instantiation_exeeded();
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}
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template<int D = 16, typename Engine, typename EngineResult, SPROUT_RECURSIVE_FUNCTION_TEMPLATE_CONTINUE(D)>
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SPROUT_CONSTEXPR sprout::random::random_result<Engine, uniform_01>
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generate(Engine const& eng, EngineResult const& rnd) const {
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typedef typename Engine::result_type base_result;
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return generate_1<D + 1>(
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eng,
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rnd,
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result_type(sprout::random::result(rnd) - eng.min()) * (
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result_type(1) / (
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result_type(eng.max() - eng.min()) + result_type(
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sprout::numeric_limits<base_result>::is_integer ? 1 : 0
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)
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)
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)
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);
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}
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template<int D = 16, typename Engine, typename EngineResult, SPROUT_RECURSIVE_FUNCTION_TEMPLATE_BREAK(D)>
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SPROUT_CONSTEXPR sprout::random::random_result<Engine, uniform_01>
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generate(Engine const&, EngineResult const&) const {
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return sprout::throw_recursive_function_template_instantiation_exeeded();
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}
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#else
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template<typename Engine, typename EngineResult>
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SPROUT_CONSTEXPR sprout::random::random_result<Engine, uniform_01>
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generate_1(Engine const&, EngineResult const& rnd, result_type result) const {
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return result < result_type(1)
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? sprout::random::random_result<Engine, uniform_01>(result, rnd.engine(), *this)
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: generate(sprout::random::next(rnd), sprout::random::next(rnd)())
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;
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}
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template<typename Engine, typename EngineResult>
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SPROUT_CONSTEXPR sprout::random::random_result<Engine, uniform_01>
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generate(Engine const& eng, EngineResult const& rnd) const {
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typedef typename Engine::result_type base_result;
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return generate_1(
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eng,
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rnd,
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result_type(sprout::random::result(rnd) - eng.min()) * (
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result_type(1) / (
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result_type(eng.max() - eng.min()) + result_type(
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sprout::numeric_limits<base_result>::is_integer ? 1 : 0
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)
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)
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)
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);
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}
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#endif
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public:
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SPROUT_CONSTEXPR uniform_01() SPROUT_DEFAULTED_DEFAULT_CONSTRUCTOR_DECL
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uniform_01(uniform_01 const&) = default;
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explicit SPROUT_CONSTEXPR uniform_01(param_type const&) SPROUT_NOEXCEPT {}
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SPROUT_CONSTEXPR result_type min() const SPROUT_NOEXCEPT {
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return result_type(0);
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}
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SPROUT_CONSTEXPR result_type max() const SPROUT_NOEXCEPT {
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return result_type(1);
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}
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SPROUT_CXX14_CONSTEXPR void reset() SPROUT_NOEXCEPT {}
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SPROUT_CONSTEXPR param_type param() const SPROUT_NOEXCEPT {
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return param_type();
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}
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SPROUT_CXX14_CONSTEXPR void param(param_type const&) SPROUT_NOEXCEPT {}
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template<typename Engine>
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SPROUT_CXX14_CONSTEXPR result_type operator()(Engine& eng) const {
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for (; ; ) {
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typedef typename Engine::result_type base_result;
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result_type result = result_type(static_cast<base_result>(eng()) - eng.min()) * (
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result_type(1) / (
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result_type(eng.max() - eng.min()) + result_type(
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sprout::numeric_limits<base_result>::is_integer ? 1 : 0
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)
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)
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);
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if (result < result_type(1)) {
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return result;
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}
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}
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}
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template<typename Engine>
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SPROUT_CONSTEXPR sprout::random::random_result<Engine, uniform_01> const operator()(Engine const& eng) const {
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return generate(eng, eng());
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}
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template<typename Engine>
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SPROUT_CXX14_CONSTEXPR result_type operator()(Engine& eng, param_type const&) const {
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return operator()(eng);
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}
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template<typename Engine>
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SPROUT_CONSTEXPR sprout::random::random_result<Engine, uniform_01> const operator()(Engine const& eng, param_type const&) const {
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return operator()(eng);
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}
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template<typename Elem, typename Traits>
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friend SPROUT_NON_CONSTEXPR std::basic_istream<Elem, Traits>& operator>>(
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std::basic_istream<Elem, Traits>& lhs,
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uniform_01&
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)
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{
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return lhs;
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}
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template<typename Elem, typename Traits>
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friend SPROUT_NON_CONSTEXPR std::basic_ostream<Elem, Traits>& operator<<(
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std::basic_ostream<Elem, Traits>& lhs,
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uniform_01 const&
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)
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{
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return lhs;
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}
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friend SPROUT_CONSTEXPR bool operator==(uniform_01 const&, uniform_01 const&) SPROUT_NOEXCEPT {
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return true;
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}
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friend SPROUT_CONSTEXPR bool operator!=(uniform_01 const& lhs, uniform_01 const& rhs) SPROUT_NOEXCEPT {
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return !(lhs == rhs);
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}
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};
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} // namespace random
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using sprout::random::uniform_01;
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} // namespace sprout
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#endif // #ifndef SPROUT_RANDOM_UNIFORM_01_HPP
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