/Src/Dependencies/Boost/boost/random/uniform_01.hpp
http://hadesmem.googlecode.com/ · C++ Header · 277 lines · 203 code · 41 blank · 33 comment · 8 complexity · c709c956a9f24dfefc96d258547ed4aa MD5 · raw file
- /* boost random/uniform_01.hpp header file
- *
- * Copyright Jens Maurer 2000-2001
- * 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)
- *
- * See http://www.boost.org for most recent version including documentation.
- *
- * $Id: uniform_01.hpp 71018 2011-04-05 21:27:52Z steven_watanabe $
- *
- * Revision history
- * 2001-02-18 moved to individual header files
- */
- #ifndef BOOST_RANDOM_UNIFORM_01_HPP
- #define BOOST_RANDOM_UNIFORM_01_HPP
- #include <iostream>
- #include <boost/config.hpp>
- #include <boost/limits.hpp>
- #include <boost/static_assert.hpp>
- #include <boost/random/detail/config.hpp>
- #include <boost/random/detail/ptr_helper.hpp>
- #include <boost/random/detail/disable_warnings.hpp>
- namespace boost {
- namespace random {
- #ifdef BOOST_RANDOM_DOXYGEN
- /**
- * The distribution function uniform_01 models a \random_distribution.
- * On each invocation, it returns a random floating-point value
- * uniformly distributed in the range [0..1).
- *
- * The template parameter RealType shall denote a float-like value type
- * with support for binary operators +, -, and /.
- *
- * Note: The current implementation is buggy, because it may not fill
- * all of the mantissa with random bits. I'm unsure how to fill a
- * (to-be-invented) @c boost::bigfloat class with random bits efficiently.
- * It's probably time for a traits class.
- */
- template<class RealType = double>
- class uniform_01
- {
- public:
- typedef RealType input_type;
- typedef RealType result_type;
- result_type min BOOST_PREVENT_MACRO_SUBSTITUTION () const;
- result_type max BOOST_PREVENT_MACRO_SUBSTITUTION () const;
- void reset();
- template<class Engine>
- result_type operator()(Engine& eng);
- #ifndef BOOST_RANDOM_NO_STREAM_OPERATORS
- template<class CharT, class Traits>
- friend std::basic_ostream<CharT,Traits>&
- operator<<(std::basic_ostream<CharT,Traits>& os, const new_uniform_01&)
- {
- return os;
- }
- template<class CharT, class Traits>
- friend std::basic_istream<CharT,Traits>&
- operator>>(std::basic_istream<CharT,Traits>& is, new_uniform_01&)
- {
- return is;
- }
- #endif
- };
- #else
- namespace detail {
- template<class RealType>
- class new_uniform_01
- {
- public:
- typedef RealType input_type;
- typedef RealType result_type;
- // compiler-generated copy ctor and copy assignment are fine
- result_type min BOOST_PREVENT_MACRO_SUBSTITUTION () const { return result_type(0); }
- result_type max BOOST_PREVENT_MACRO_SUBSTITUTION () const { return result_type(1); }
- void reset() { }
- template<class Engine>
- result_type operator()(Engine& eng) {
- for (;;) {
- typedef typename Engine::result_type base_result;
- result_type factor = result_type(1) /
- (result_type((eng.max)()-(eng.min)()) +
- result_type(std::numeric_limits<base_result>::is_integer ? 1 : 0));
- result_type result = result_type(eng() - (eng.min)()) * factor;
- if (result < result_type(1))
- return result;
- }
- }
- #ifndef BOOST_RANDOM_NO_STREAM_OPERATORS
- template<class CharT, class Traits>
- friend std::basic_ostream<CharT,Traits>&
- operator<<(std::basic_ostream<CharT,Traits>& os, const new_uniform_01&)
- {
- return os;
- }
- template<class CharT, class Traits>
- friend std::basic_istream<CharT,Traits>&
- operator>>(std::basic_istream<CharT,Traits>& is, new_uniform_01&)
- {
- return is;
- }
- #endif
- };
- template<class UniformRandomNumberGenerator, class RealType>
- class backward_compatible_uniform_01
- {
- typedef boost::random::detail::ptr_helper<UniformRandomNumberGenerator> traits;
- public:
- typedef UniformRandomNumberGenerator base_type;
- typedef RealType result_type;
- BOOST_STATIC_CONSTANT(bool, has_fixed_range = false);
- #if !defined(BOOST_NO_LIMITS_COMPILE_TIME_CONSTANTS) && !(defined(BOOST_MSVC) && BOOST_MSVC <= 1300)
- BOOST_STATIC_ASSERT(!std::numeric_limits<RealType>::is_integer);
- #endif
- explicit backward_compatible_uniform_01(typename traits::rvalue_type rng)
- : _rng(rng),
- _factor(result_type(1) /
- (result_type((base().max)()-(base().min)()) +
- result_type(std::numeric_limits<base_result>::is_integer ? 1 : 0)))
- {
- }
- // compiler-generated copy ctor and copy assignment are fine
- result_type min BOOST_PREVENT_MACRO_SUBSTITUTION () const { return result_type(0); }
- result_type max BOOST_PREVENT_MACRO_SUBSTITUTION () const { return result_type(1); }
- typename traits::value_type& base() { return traits::ref(_rng); }
- const typename traits::value_type& base() const { return traits::ref(_rng); }
- void reset() { }
- result_type operator()() {
- for (;;) {
- result_type result = result_type(base()() - (base().min)()) * _factor;
- if (result < result_type(1))
- return result;
- }
- }
- #if !defined(BOOST_NO_OPERATORS_IN_NAMESPACE) && !defined(BOOST_NO_MEMBER_TEMPLATE_FRIENDS)
- template<class CharT, class Traits>
- friend std::basic_ostream<CharT,Traits>&
- operator<<(std::basic_ostream<CharT,Traits>& os, const backward_compatible_uniform_01& u)
- {
- os << u._rng;
- return os;
- }
- template<class CharT, class Traits>
- friend std::basic_istream<CharT,Traits>&
- operator>>(std::basic_istream<CharT,Traits>& is, backward_compatible_uniform_01& u)
- {
- is >> u._rng;
- return is;
- }
- #endif
- private:
- typedef typename traits::value_type::result_type base_result;
- UniformRandomNumberGenerator _rng;
- result_type _factor;
- };
- #ifndef BOOST_NO_INCLASS_MEMBER_INITIALIZATION
- // A definition is required even for integral static constants
- template<class UniformRandomNumberGenerator, class RealType>
- const bool backward_compatible_uniform_01<UniformRandomNumberGenerator, RealType>::has_fixed_range;
- #endif
- template<class UniformRandomNumberGenerator>
- struct select_uniform_01
- {
- template<class RealType>
- struct apply
- {
- typedef backward_compatible_uniform_01<UniformRandomNumberGenerator, RealType> type;
- };
- };
- template<>
- struct select_uniform_01<float>
- {
- template<class RealType>
- struct apply
- {
- typedef new_uniform_01<float> type;
- };
- };
- template<>
- struct select_uniform_01<double>
- {
- template<class RealType>
- struct apply
- {
- typedef new_uniform_01<double> type;
- };
- };
- template<>
- struct select_uniform_01<long double>
- {
- template<class RealType>
- struct apply
- {
- typedef new_uniform_01<long double> type;
- };
- };
- }
- // Because it is so commonly used: uniform distribution on the real [0..1)
- // range. This allows for specializations to avoid a costly int -> float
- // conversion plus float multiplication
- template<class UniformRandomNumberGenerator = double, class RealType = double>
- class uniform_01
- : public detail::select_uniform_01<UniformRandomNumberGenerator>::BOOST_NESTED_TEMPLATE apply<RealType>::type
- {
- typedef typename detail::select_uniform_01<UniformRandomNumberGenerator>::BOOST_NESTED_TEMPLATE apply<RealType>::type impl_type;
- typedef boost::random::detail::ptr_helper<UniformRandomNumberGenerator> traits;
- public:
- uniform_01() {}
- explicit uniform_01(typename traits::rvalue_type rng)
- : impl_type(rng)
- {
- }
- #if !defined(BOOST_NO_OPERATORS_IN_NAMESPACE) && !defined(BOOST_NO_MEMBER_TEMPLATE_FRIENDS)
- template<class CharT, class Traits>
- friend std::basic_ostream<CharT,Traits>&
- operator<<(std::basic_ostream<CharT,Traits>& os, const uniform_01& u)
- {
- os << static_cast<const impl_type&>(u);
- return os;
- }
- template<class CharT, class Traits>
- friend std::basic_istream<CharT,Traits>&
- operator>>(std::basic_istream<CharT,Traits>& is, uniform_01& u)
- {
- is >> static_cast<impl_type&>(u);
- return is;
- }
- #endif
- };
- #endif
- } // namespace random
- using random::uniform_01;
- } // namespace boost
- #include <boost/random/detail/enable_warnings.hpp>
- #endif // BOOST_RANDOM_UNIFORM_01_HPP