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Diffstat (limited to 'src/third_party/boost-1.60.0/boost/random/discard_block.hpp')
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1 files changed, 241 insertions, 0 deletions
diff --git a/src/third_party/boost-1.60.0/boost/random/discard_block.hpp b/src/third_party/boost-1.60.0/boost/random/discard_block.hpp new file mode 100644 index 00000000000..f3c6b82b87f --- /dev/null +++ b/src/third_party/boost-1.60.0/boost/random/discard_block.hpp @@ -0,0 +1,241 @@ +/* boost random/discard_block.hpp header file + * + * Copyright Jens Maurer 2002 + * Copyright Steven Watanabe 2010 + * 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 + * 2001-03-02 created + */ + +#ifndef BOOST_RANDOM_DISCARD_BLOCK_HPP +#define BOOST_RANDOM_DISCARD_BLOCK_HPP + +#include <iostream> +#include <boost/config.hpp> +#include <boost/cstdint.hpp> +#include <boost/limits.hpp> +#include <boost/static_assert.hpp> +#include <boost/random/detail/config.hpp> +#include <boost/random/detail/seed.hpp> +#include <boost/random/detail/seed_impl.hpp> + + +namespace boost { +namespace random { + +/** + * The class template \discard_block_engine is a model of + * \pseudo_random_number_generator. It modifies + * another generator by discarding parts of its output. + * Out of every block of @c p results, the first @c r + * will be returned and the rest discarded. + * + * Requires: 0 < p <= r + */ +template<class UniformRandomNumberGenerator, std::size_t p, std::size_t r> +class discard_block_engine +{ + typedef typename detail::seed_type< + typename UniformRandomNumberGenerator::result_type>::type seed_type; +public: + typedef UniformRandomNumberGenerator base_type; + typedef typename base_type::result_type result_type; + + BOOST_STATIC_CONSTANT(std::size_t, block_size = p); + BOOST_STATIC_CONSTANT(std::size_t, used_block = r); + + BOOST_STATIC_CONSTANT(bool, has_fixed_range = false); + BOOST_STATIC_CONSTANT(std::size_t, total_block = p); + BOOST_STATIC_CONSTANT(std::size_t, returned_block = r); + + BOOST_STATIC_ASSERT(total_block >= returned_block); + + /** Uses the default seed for the base generator. */ + discard_block_engine() : _rng(), _n(0) { } + /** Constructs a new \discard_block_engine with a copy of rng. */ + explicit discard_block_engine(const base_type & rng) : _rng(rng), _n(0) { } + +#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES + /** Constructs a new \discard_block_engine with rng. */ + explicit discard_block_engine(base_type && rng) : _rng(rng), _n(0) { } +#endif + + /** + * Creates a new \discard_block_engine and seeds the underlying + * generator with @c value + */ + BOOST_RANDOM_DETAIL_ARITHMETIC_CONSTRUCTOR(discard_block_engine, + seed_type, value) + { _rng.seed(value); _n = 0; } + + /** + * Creates a new \discard_block_engine and seeds the underlying + * generator with @c seq + */ + BOOST_RANDOM_DETAIL_SEED_SEQ_CONSTRUCTOR(discard_block_engine, SeedSeq, seq) + { _rng.seed(seq); _n = 0; } + + /** + * Creates a new \discard_block_engine and seeds the underlying + * generator with first and last. + */ + template<class It> discard_block_engine(It& first, It last) + : _rng(first, last), _n(0) { } + + /** default seeds the underlying generator. */ + void seed() { _rng.seed(); _n = 0; } + /** Seeds the underlying generator with s. */ + BOOST_RANDOM_DETAIL_ARITHMETIC_SEED(discard_block_engine, seed_type, s) + { _rng.seed(s); _n = 0; } + /** Seeds the underlying generator with seq. */ + BOOST_RANDOM_DETAIL_SEED_SEQ_SEED(discard_block_engine, SeedSeq, seq) + { _rng.seed(seq); _n = 0; } + /** Seeds the underlying generator with first and last. */ + template<class It> void seed(It& first, It last) + { _rng.seed(first, last); _n = 0; } + + /** Returns the underlying engine. */ + const base_type& base() const { return _rng; } + + /** Returns the next value of the generator. */ + result_type operator()() + { + if(_n >= returned_block) { + // discard values of random number generator + // Don't use discard, since we still need to + // be somewhat compatible with TR1. + // _rng.discard(total_block - _n); + for(std::size_t i = 0; i < total_block - _n; ++i) { + _rng(); + } + _n = 0; + } + ++_n; + return _rng(); + } + + void discard(boost::uintmax_t z) + { + for(boost::uintmax_t j = 0; j < z; ++j) { + (*this)(); + } + } + + template<class It> + void generate(It first, It last) + { detail::generate(*this, first, last); } + + /** + * Returns the smallest value that the generator can produce. + * This is the same as the minimum of the underlying generator. + */ + static result_type min BOOST_PREVENT_MACRO_SUBSTITUTION () + { return (base_type::min)(); } + /** + * Returns the largest value that the generator can produce. + * This is the same as the maximum of the underlying generator. + */ + static result_type max BOOST_PREVENT_MACRO_SUBSTITUTION () + { return (base_type::max)(); } + +#ifndef BOOST_RANDOM_NO_STREAM_OPERATORS + /** Writes a \discard_block_engine to a @c std::ostream. */ + template<class CharT, class Traits> + friend std::basic_ostream<CharT,Traits>& + operator<<(std::basic_ostream<CharT,Traits>& os, + const discard_block_engine& s) + { + os << s._rng << ' ' << s._n; + return os; + } + + /** Reads a \discard_block_engine from a @c std::istream. */ + template<class CharT, class Traits> + friend std::basic_istream<CharT,Traits>& + operator>>(std::basic_istream<CharT,Traits>& is, discard_block_engine& s) + { + is >> s._rng >> std::ws >> s._n; + return is; + } +#endif + + /** Returns true if the two generators will produce identical sequences. */ + friend bool operator==(const discard_block_engine& x, + const discard_block_engine& y) + { return x._rng == y._rng && x._n == y._n; } + /** Returns true if the two generators will produce different sequences. */ + friend bool operator!=(const discard_block_engine& x, + const discard_block_engine& y) + { return !(x == y); } + +private: + base_type _rng; + std::size_t _n; +}; + +#ifndef BOOST_NO_INCLASS_MEMBER_INITIALIZATION +// A definition is required even for integral static constants +template<class URNG, std::size_t p, std::size_t r> +const bool discard_block_engine<URNG, p, r>::has_fixed_range; +template<class URNG, std::size_t p, std::size_t r> +const std::size_t discard_block_engine<URNG, p, r>::total_block; +template<class URNG, std::size_t p, std::size_t r> +const std::size_t discard_block_engine<URNG, p, r>::returned_block; +template<class URNG, std::size_t p, std::size_t r> +const std::size_t discard_block_engine<URNG, p, r>::block_size; +template<class URNG, std::size_t p, std::size_t r> +const std::size_t discard_block_engine<URNG, p, r>::used_block; +#endif + +/// \cond \show_deprecated + +template<class URNG, int p, int r> +class discard_block : public discard_block_engine<URNG, p, r> +{ + typedef discard_block_engine<URNG, p, r> base_t; +public: + typedef typename base_t::result_type result_type; + discard_block() {} + template<class T> + discard_block(T& arg) : base_t(arg) {} + template<class T> + discard_block(const T& arg) : base_t(arg) {} + template<class It> + discard_block(It& first, It last) : base_t(first, last) {} + result_type min BOOST_PREVENT_MACRO_SUBSTITUTION () + { return (this->base().min)(); } + result_type max BOOST_PREVENT_MACRO_SUBSTITUTION () + { return (this->base().max)(); } +}; + +/// \endcond + +namespace detail { + + template<class Engine> + struct generator_bits; + + template<class URNG, std::size_t p, std::size_t r> + struct generator_bits<discard_block_engine<URNG, p, r> > { + static std::size_t value() { return generator_bits<URNG>::value(); } + }; + + template<class URNG, int p, int r> + struct generator_bits<discard_block<URNG, p, r> > { + static std::size_t value() { return generator_bits<URNG>::value(); } + }; + +} + +} // namespace random + +} // namespace boost + +#endif // BOOST_RANDOM_DISCARD_BLOCK_HPP |