Added boost header

test/external/boost/random/additive_combine.hpp

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+/* 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: additive_combine.hpp 71018 2011-04-05 21:27:52Z steven_watanabe $
+ *
+ * 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