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Diffstat (limited to 'src/third_party/boost-1.69.0/boost/random/additive_combine.hpp')
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diff --git a/src/third_party/boost-1.69.0/boost/random/additive_combine.hpp b/src/third_party/boost-1.69.0/boost/random/additive_combine.hpp new file mode 100644 index 00000000000..d786e18473a --- /dev/null +++ b/src/third_party/boost-1.69.0/boost/random/additive_combine.hpp @@ -0,0 +1,283 @@ +/* boost random/additive_combine.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. + * + * $Id$ + * + * Revision history + * 2001-02-18 moved to individual header files + */ + +#ifndef BOOST_RANDOM_ADDITIVE_COMBINE_HPP +#define BOOST_RANDOM_ADDITIVE_COMBINE_HPP + +#include <istream> +#include <iosfwd> +#include <algorithm> // for std::min and std::max +#include <boost/config.hpp> +#include <boost/cstdint.hpp> +#include <boost/random/detail/config.hpp> +#include <boost/random/detail/operators.hpp> +#include <boost/random/detail/seed.hpp> +#include <boost/random/linear_congruential.hpp> + +namespace boost { +namespace random { + +/** + * An instantiation of class template @c additive_combine_engine models a + * \pseudo_random_number_generator. It combines two multiplicative + * \linear_congruential_engine number generators, i.e. those with @c c = 0. + * It is described in + * + * @blockquote + * "Efficient and Portable Combined Random Number Generators", Pierre L'Ecuyer, + * Communications of the ACM, Vol. 31, No. 6, June 1988, pp. 742-749, 774 + * @endblockquote + * + * The template parameters MLCG1 and MLCG2 shall denote two different + * \linear_congruential_engine number generators, each with c = 0. Each + * invocation returns a random number + * X(n) := (MLCG1(n) - MLCG2(n)) mod (m1 - 1), + * where m1 denotes the modulus of MLCG1. + */ +template<class MLCG1, class MLCG2> +class additive_combine_engine +{ +public: + typedef MLCG1 first_base; + typedef MLCG2 second_base; + typedef typename MLCG1::result_type result_type; + + // Required by old Boost.Random concept + BOOST_STATIC_CONSTANT(bool, has_fixed_range = false); + /** + * Returns the smallest value that the generator can produce + */ + static result_type min BOOST_PREVENT_MACRO_SUBSTITUTION () + { return 1; } + /** + * Returns the largest value that the generator can produce + */ + static result_type max BOOST_PREVENT_MACRO_SUBSTITUTION () + { return MLCG1::modulus-1; } + + /** + * Constructs an @c additive_combine_engine using the + * default constructors of the two base generators. + */ + additive_combine_engine() : _mlcg1(), _mlcg2() { } + /** + * Constructs an @c additive_combine_engine, using seed as + * the constructor argument for both base generators. + */ + BOOST_RANDOM_DETAIL_ARITHMETIC_CONSTRUCTOR(additive_combine_engine, + result_type, seed_arg) + { + _mlcg1.seed(seed_arg); + _mlcg2.seed(seed_arg); + } + /** + * Constructs an @c additive_combine_engine, using seq as + * the constructor argument for both base generators. + * + * @xmlwarning + * The semantics of this function are liable to change. + * A @c seed_seq is designed to generate all the seeds + * in one shot, but this seeds the two base engines + * independantly and probably ends up giving the same + * sequence to both. + * @endxmlwarning + */ + BOOST_RANDOM_DETAIL_SEED_SEQ_CONSTRUCTOR(additive_combine_engine, + SeedSeq, seq) + { + _mlcg1.seed(seq); + _mlcg2.seed(seq); + } + /** + * Constructs an @c additive_combine_engine, using + * @c seed1 and @c seed2 as the constructor argument to + * the first and second base generators, respectively. + */ + additive_combine_engine(typename MLCG1::result_type seed1, + typename MLCG2::result_type seed2) + : _mlcg1(seed1), _mlcg2(seed2) { } + /** + * Contructs an @c additive_combine_engine with + * values from the range defined by the input iterators first + * and last. first will be modified to point to the element + * after the last one used. + * + * Throws: @c std::invalid_argument if the input range is too small. + * + * Exception Safety: Basic + */ + template<class It> additive_combine_engine(It& first, It last) + : _mlcg1(first, last), _mlcg2(first, last) { } + + /** + * Seeds an @c additive_combine_engine using the default + * seeds of the two base generators. + */ + void seed() + { + _mlcg1.seed(); + _mlcg2.seed(); + } + + /** + * Seeds an @c additive_combine_engine, using @c seed as the + * seed for both base generators. + */ + BOOST_RANDOM_DETAIL_ARITHMETIC_SEED(additive_combine_engine, + result_type, seed_arg) + { + _mlcg1.seed(seed_arg); + _mlcg2.seed(seed_arg); + } + + /** + * Seeds an @c additive_combine_engine, using @c seq to + * seed both base generators. + * + * See the warning on the corresponding constructor. + */ + BOOST_RANDOM_DETAIL_SEED_SEQ_SEED(additive_combine_engine, + SeedSeq, seq) + { + _mlcg1.seed(seq); + _mlcg2.seed(seq); + } + + /** + * Seeds an @c additive_combine generator, using @c seed1 and @c seed2 as + * the seeds to the first and second base generators, respectively. + */ + void seed(typename MLCG1::result_type seed1, + typename MLCG2::result_type seed2) + { + _mlcg1.seed(seed1); + _mlcg2.seed(seed2); + } + + /** + * Seeds an @c additive_combine_engine with + * values from the range defined by the input iterators first + * and last. first will be modified to point to the element + * after the last one used. + * + * Throws: @c std::invalid_argument if the input range is too small. + * + * Exception Safety: Basic + */ + template<class It> void seed(It& first, It last) + { + _mlcg1.seed(first, last); + _mlcg2.seed(first, last); + } + + /** Returns the next value of the generator. */ + result_type operator()() { + result_type val1 = _mlcg1(); + result_type val2 = _mlcg2(); + if(val2 < val1) return val1 - val2; + else return val1 - val2 + MLCG1::modulus - 1; + } + + /** Fills a range with random values */ + template<class Iter> + void generate(Iter first, Iter last) + { detail::generate_from_int(*this, first, last); } + + /** Advances the state of the generator by @c z. */ + void discard(boost::uintmax_t z) + { + _mlcg1.discard(z); + _mlcg2.discard(z); + } + + /** + * Writes the state of an @c additive_combine_engine to a @c + * std::ostream. The textual representation of an @c + * additive_combine_engine is the textual representation of + * the first base generator followed by the textual representation + * of the second base generator. + */ + BOOST_RANDOM_DETAIL_OSTREAM_OPERATOR(os, additive_combine_engine, r) + { os << r._mlcg1 << ' ' << r._mlcg2; return os; } + + /** + * Reads the state of an @c additive_combine_engine from a + * @c std::istream. + */ + BOOST_RANDOM_DETAIL_ISTREAM_OPERATOR(is, additive_combine_engine, r) + { is >> r._mlcg1 >> std::ws >> r._mlcg2; return is; } + + /** + * Returns: true iff the two @c additive_combine_engines will + * produce the same sequence of values. + */ + BOOST_RANDOM_DETAIL_EQUALITY_OPERATOR(additive_combine_engine, x, y) + { return x._mlcg1 == y._mlcg1 && x._mlcg2 == y._mlcg2; } + /** + * Returns: true iff the two @c additive_combine_engines will + * produce different sequences of values. + */ + BOOST_RANDOM_DETAIL_INEQUALITY_OPERATOR(additive_combine_engine) + +private: + MLCG1 _mlcg1; + MLCG2 _mlcg2; +}; + +#ifndef BOOST_NO_INCLASS_MEMBER_INITIALIZATION +template<class MLCG1, class MLCG2> +const bool additive_combine_engine<MLCG1, MLCG2>::has_fixed_range; +#endif + +/// \cond show_deprecated + +/** Provided for backwards compatibility. */ +template<class MLCG1, class MLCG2, typename MLCG1::result_type val = 0> +class additive_combine : public additive_combine_engine<MLCG1, MLCG2> +{ + typedef additive_combine_engine<MLCG1, MLCG2> base_t; +public: + typedef typename base_t::result_type result_type; + additive_combine() {} + template<class T> + additive_combine(T& arg) : base_t(arg) {} + template<class T> + additive_combine(const T& arg) : base_t(arg) {} + template<class It> + additive_combine(It& first, It last) : base_t(first, last) {} +}; + +/// \endcond + +/** + * The specialization \ecuyer1988 was suggested in + * + * @blockquote + * "Efficient and Portable Combined Random Number Generators", Pierre L'Ecuyer, + * Communications of the ACM, Vol. 31, No. 6, June 1988, pp. 742-749, 774 + * @endblockquote + */ +typedef additive_combine_engine< + linear_congruential_engine<uint32_t, 40014, 0, 2147483563>, + linear_congruential_engine<uint32_t, 40692, 0, 2147483399> +> ecuyer1988; + +} // namespace random + +using random::ecuyer1988; + +} // namespace boost + +#endif // BOOST_RANDOM_ADDITIVE_COMBINE_HPP |