comparison DEPENDENCIES/generic/include/boost/random/discard_block.hpp @ 16:2665513ce2d3

Add boost headers

+/* 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: discard_block.hpp 72951 2011-07-07 04:57:37Z steven_watanabe $
+ *
+ * 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>
+
+
+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_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