--- /dev/null
+// random number generation -*- C++ -*-
+
+// Copyright (C) 2007, 2008, 2009 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// Under Section 7 of GPL version 3, you are granted additional
+// permissions described in the GCC Runtime Library Exception, version
+// 3.1, as published by the Free Software Foundation.
+
+// You should have received a copy of the GNU General Public License and
+// a copy of the GCC Runtime Library Exception along with this program;
+// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+// <http://www.gnu.org/licenses/>.
+
+/**
+ * @file tr1_impl/random
+ * This is an internal header file, included by other library headers.
+ * You should not attempt to use it directly.
+ */
+
+namespace std
+{
+_GLIBCXX_BEGIN_NAMESPACE_TR1
+
+ // [5.1] Random number generation
+
+ /**
+ * @defgroup tr1_random Random Number Generation
+ * @ingroup numerics
+ * A facility for generating random numbers on selected distributions.
+ * @{
+ */
+
+ /*
+ * Implementation-space details.
+ */
+ namespace __detail
+ {
+ template<typename _UIntType, int __w,
+ bool = __w < std::numeric_limits<_UIntType>::digits>
+ struct _Shift
+ { static const _UIntType __value = 0; };
+
+ template<typename _UIntType, int __w>
+ struct _Shift<_UIntType, __w, true>
+ { static const _UIntType __value = _UIntType(1) << __w; };
+
+ template<typename _Tp, _Tp __a, _Tp __c, _Tp __m, bool>
+ struct _Mod;
+
+ // Dispatch based on modulus value to prevent divide-by-zero compile-time
+ // errors when m == 0.
+ template<typename _Tp, _Tp __a, _Tp __c, _Tp __m>
+ inline _Tp
+ __mod(_Tp __x)
+ { return _Mod<_Tp, __a, __c, __m, __m == 0>::__calc(__x); }
+
+ typedef __gnu_cxx::__conditional_type<(sizeof(unsigned) == 4),
+ unsigned, unsigned long>::__type _UInt32Type;
+
+ /*
+ * An adaptor class for converting the output of any Generator into
+ * the input for a specific Distribution.
+ */
+ template<typename _Engine, typename _Distribution>
+ struct _Adaptor
+ {
+ typedef typename remove_reference<_Engine>::type _BEngine;
+ typedef typename _BEngine::result_type _Engine_result_type;
+ typedef typename _Distribution::input_type result_type;
+
+ public:
+ _Adaptor(const _Engine& __g)
+ : _M_g(__g) { }
+
+ result_type
+ min() const
+ {
+ result_type __return_value;
+ if (is_integral<_Engine_result_type>::value
+ && is_integral<result_type>::value)
+ __return_value = _M_g.min();
+ else
+ __return_value = result_type(0);
+ return __return_value;
+ }
+
+ result_type
+ max() const
+ {
+ result_type __return_value;
+ if (is_integral<_Engine_result_type>::value
+ && is_integral<result_type>::value)
+ __return_value = _M_g.max();
+ else if (!is_integral<result_type>::value)
+ __return_value = result_type(1);
+ else
+ __return_value = std::numeric_limits<result_type>::max() - 1;
+ return __return_value;
+ }
+
+ /*
+ * Converts a value generated by the adapted random number generator
+ * into a value in the input domain for the dependent random number
+ * distribution.
+ *
+ * Because the type traits are compile time constants only the
+ * appropriate clause of the if statements will actually be emitted
+ * by the compiler.
+ */
+ result_type
+ operator()()
+ {
+ result_type __return_value;
+ if (is_integral<_Engine_result_type>::value
+ && is_integral<result_type>::value)
+ __return_value = _M_g();
+ else if (!is_integral<_Engine_result_type>::value
+ && !is_integral<result_type>::value)
+ __return_value = result_type(_M_g() - _M_g.min())
+ / result_type(_M_g.max() - _M_g.min());
+ else if (is_integral<_Engine_result_type>::value
+ && !is_integral<result_type>::value)
+ __return_value = result_type(_M_g() - _M_g.min())
+ / result_type(_M_g.max() - _M_g.min() + result_type(1));
+ else
+ __return_value = (((_M_g() - _M_g.min())
+ / (_M_g.max() - _M_g.min()))
+ * std::numeric_limits<result_type>::max());
+ return __return_value;
+ }
+
+ private:
+ _Engine _M_g;
+ };
+
+ // Specialization for _Engine*.
+ template<typename _Engine, typename _Distribution>
+ struct _Adaptor<_Engine*, _Distribution>
+ {
+ typedef typename _Engine::result_type _Engine_result_type;
+ typedef typename _Distribution::input_type result_type;
+
+ public:
+ _Adaptor(_Engine* __g)
+ : _M_g(__g) { }
+
+ result_type
+ min() const
+ {
+ result_type __return_value;
+ if (is_integral<_Engine_result_type>::value
+ && is_integral<result_type>::value)
+ __return_value = _M_g->min();
+ else
+ __return_value = result_type(0);
+ return __return_value;
+ }
+
+ result_type
+ max() const
+ {
+ result_type __return_value;
+ if (is_integral<_Engine_result_type>::value
+ && is_integral<result_type>::value)
+ __return_value = _M_g->max();
+ else if (!is_integral<result_type>::value)
+ __return_value = result_type(1);
+ else
+ __return_value = std::numeric_limits<result_type>::max() - 1;
+ return __return_value;
+ }
+
+ result_type
+ operator()()
+ {
+ result_type __return_value;
+ if (is_integral<_Engine_result_type>::value
+ && is_integral<result_type>::value)
+ __return_value = (*_M_g)();
+ else if (!is_integral<_Engine_result_type>::value
+ && !is_integral<result_type>::value)
+ __return_value = result_type((*_M_g)() - _M_g->min())
+ / result_type(_M_g->max() - _M_g->min());
+ else if (is_integral<_Engine_result_type>::value
+ && !is_integral<result_type>::value)
+ __return_value = result_type((*_M_g)() - _M_g->min())
+ / result_type(_M_g->max() - _M_g->min() + result_type(1));
+ else
+ __return_value = ((((*_M_g)() - _M_g->min())
+ / (_M_g->max() - _M_g->min()))
+ * std::numeric_limits<result_type>::max());
+ return __return_value;
+ }
+
+ private:
+ _Engine* _M_g;
+ };
+ } // namespace __detail
+
+ /**
+ * Produces random numbers on a given distribution function using a
+ * non-uniform random number generation engine.
+ *
+ * @todo the engine_value_type needs to be studied more carefully.
+ */
+ template<typename _Engine, typename _Dist>
+ class variate_generator
+ {
+ // Concept requirements.
+ __glibcxx_class_requires(_Engine, _CopyConstructibleConcept)
+ // __glibcxx_class_requires(_Engine, _EngineConcept)
+ // __glibcxx_class_requires(_Dist, _EngineConcept)
+
+ public:
+ typedef _Engine engine_type;
+ typedef __detail::_Adaptor<_Engine, _Dist> engine_value_type;
+ typedef _Dist distribution_type;
+ typedef typename _Dist::result_type result_type;
+
+ // tr1:5.1.1 table 5.1 requirement
+ typedef typename __gnu_cxx::__enable_if<
+ is_arithmetic<result_type>::value, result_type>::__type _IsValidType;
+
+ /**
+ * Constructs a variate generator with the uniform random number
+ * generator @p __eng for the random distribution @p __dist.
+ *
+ * @throws Any exceptions which may thrown by the copy constructors of
+ * the @p _Engine or @p _Dist objects.
+ */
+ variate_generator(engine_type __eng, distribution_type __dist)
+ : _M_engine(__eng), _M_dist(__dist) { }
+
+ /**
+ * Gets the next generated value on the distribution.
+ */
+ result_type
+ operator()()
+ { return _M_dist(_M_engine); }
+
+ /**
+ * WTF?
+ */
+ template<typename _Tp>
+ result_type
+ operator()(_Tp __value)
+ { return _M_dist(_M_engine, __value); }
+
+ /**
+ * Gets a reference to the underlying uniform random number generator
+ * object.
+ */
+ engine_value_type&
+ engine()
+ { return _M_engine; }
+
+ /**
+ * Gets a const reference to the underlying uniform random number
+ * generator object.
+ */
+ const engine_value_type&
+ engine() const
+ { return _M_engine; }
+
+ /**
+ * Gets a reference to the underlying random distribution.
+ */
+ distribution_type&
+ distribution()
+ { return _M_dist; }
+
+ /**
+ * Gets a const reference to the underlying random distribution.
+ */
+ const distribution_type&
+ distribution() const
+ { return _M_dist; }
+
+ /**
+ * Gets the closed lower bound of the distribution interval.
+ */
+ result_type
+ min() const
+ { return this->distribution().min(); }
+
+ /**
+ * Gets the closed upper bound of the distribution interval.
+ */
+ result_type
+ max() const
+ { return this->distribution().max(); }
+
+ private:
+ engine_value_type _M_engine;
+ distribution_type _M_dist;
+ };
+
+
+ /**
+ * @defgroup tr1_random_generators Random Number Generators
+ * @ingroup tr1_random
+ *
+ * These classes define objects which provide random or pseudorandom
+ * numbers, either from a discrete or a continuous interval. The
+ * random number generator supplied as a part of this library are
+ * all uniform random number generators which provide a sequence of
+ * random number uniformly distributed over their range.
+ *
+ * A number generator is a function object with an operator() that
+ * takes zero arguments and returns a number.
+ *
+ * A compliant random number generator must satisfy the following
+ * requirements. <table border=1 cellpadding=10 cellspacing=0>
+ * <caption align=top>Random Number Generator Requirements</caption>
+ * <tr><td>To be documented.</td></tr> </table>
+ *
+ * @{
+ */
+
+ /**
+ * @brief A model of a linear congruential random number generator.
+ *
+ * A random number generator that produces pseudorandom numbers using the
+ * linear function @f$x_{i+1}\leftarrow(ax_{i} + c) \bmod m @f$.
+ *
+ * The template parameter @p _UIntType must be an unsigned integral type
+ * large enough to store values up to (__m-1). If the template parameter
+ * @p __m is 0, the modulus @p __m used is
+ * std::numeric_limits<_UIntType>::max() plus 1. Otherwise, the template
+ * parameters @p __a and @p __c must be less than @p __m.
+ *
+ * The size of the state is @f$ 1 @f$.
+ */
+ template<class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
+ class linear_congruential
+ {
+ __glibcxx_class_requires(_UIntType, _UnsignedIntegerConcept)
+ // __glibcpp_class_requires(__a < __m && __c < __m)
+
+ public:
+ /** The type of the generated random value. */
+ typedef _UIntType result_type;
+
+ /** The multiplier. */
+ static const _UIntType multiplier = __a;
+ /** An increment. */
+ static const _UIntType increment = __c;
+ /** The modulus. */
+ static const _UIntType modulus = __m;
+
+ /**
+ * Constructs a %linear_congruential random number generator engine with
+ * seed @p __s. The default seed value is 1.
+ *
+ * @param __s The initial seed value.
+ */
+ explicit
+ linear_congruential(unsigned long __x0 = 1)
+ { this->seed(__x0); }
+
+ /**
+ * Constructs a %linear_congruential random number generator engine
+ * seeded from the generator function @p __g.
+ *
+ * @param __g The seed generator function.
+ */
+ template<class _Gen>
+ linear_congruential(_Gen& __g)
+ { this->seed(__g); }
+
+ /**
+ * Reseeds the %linear_congruential random number generator engine
+ * sequence to the seed @g __s.
+ *
+ * @param __s The new seed.
+ */
+ void
+ seed(unsigned long __s = 1);
+
+ /**
+ * Reseeds the %linear_congruential random number generator engine
+ * sequence using values from the generator function @p __g.
+ *
+ * @param __g the seed generator function.
+ */
+ template<class _Gen>
+ void
+ seed(_Gen& __g)
+ { seed(__g, typename is_fundamental<_Gen>::type()); }
+
+ /**
+ * Gets the smallest possible value in the output range.
+ *
+ * The minimum depends on the @p __c parameter: if it is zero, the
+ * minimum generated must be > 0, otherwise 0 is allowed.
+ */
+ result_type
+ min() const
+ { return (__detail::__mod<_UIntType, 1, 0, __m>(__c) == 0) ? 1 : 0; }
+
+ /**
+ * Gets the largest possible value in the output range.
+ */
+ result_type
+ max() const
+ { return __m - 1; }
+
+ /**
+ * Gets the next random number in the sequence.
+ */
+ result_type
+ operator()();
+
+ /**
+ * Compares two linear congruential random number generator
+ * objects of the same type for equality.
+ *
+ * @param __lhs A linear congruential random number generator object.
+ * @param __rhs Another linear congruential random number generator obj.
+ *
+ * @returns true if the two objects are equal, false otherwise.
+ */
+ friend bool
+ operator==(const linear_congruential& __lhs,
+ const linear_congruential& __rhs)
+ { return __lhs._M_x == __rhs._M_x; }
+
+ /**
+ * Compares two linear congruential random number generator
+ * objects of the same type for inequality.
+ *
+ * @param __lhs A linear congruential random number generator object.
+ * @param __rhs Another linear congruential random number generator obj.
+ *
+ * @returns true if the two objects are not equal, false otherwise.
+ */
+ friend bool
+ operator!=(const linear_congruential& __lhs,
+ const linear_congruential& __rhs)
+ { return !(__lhs == __rhs); }
+
+ /**
+ * Writes the textual representation of the state x(i) of x to @p __os.
+ *
+ * @param __os The output stream.
+ * @param __lcr A % linear_congruential random number generator.
+ * @returns __os.
+ */
+ template<class _UIntType1, _UIntType1 __a1, _UIntType1 __c1,
+ _UIntType1 __m1,
+ typename _CharT, typename _Traits>
+ friend std::basic_ostream<_CharT, _Traits>&
+ operator<<(std::basic_ostream<_CharT, _Traits>& __os,
+ const linear_congruential<_UIntType1, __a1, __c1,
+ __m1>& __lcr);
+
+ /**
+ * Sets the state of the engine by reading its textual
+ * representation from @p __is.
+ *
+ * The textual representation must have been previously written using an
+ * output stream whose imbued locale and whose type's template
+ * specialization arguments _CharT and _Traits were the same as those of
+ * @p __is.
+ *
+ * @param __is The input stream.
+ * @param __lcr A % linear_congruential random number generator.
+ * @returns __is.
+ */
+ template<class _UIntType1, _UIntType1 __a1, _UIntType1 __c1,
+ _UIntType1 __m1,
+ typename _CharT, typename _Traits>
+ friend std::basic_istream<_CharT, _Traits>&
+ operator>>(std::basic_istream<_CharT, _Traits>& __is,
+ linear_congruential<_UIntType1, __a1, __c1, __m1>& __lcr);
+
+ private:
+ template<class _Gen>
+ void
+ seed(_Gen& __g, true_type)
+ { return seed(static_cast<unsigned long>(__g)); }
+
+ template<class _Gen>
+ void
+ seed(_Gen& __g, false_type);
+
+ _UIntType _M_x;
+ };
+
+ /**
+ * The classic Minimum Standard rand0 of Lewis, Goodman, and Miller.
+ */
+ typedef linear_congruential<unsigned long, 16807, 0, 2147483647> minstd_rand0;
+
+ /**
+ * An alternative LCR (Lehmer Generator function) .
+ */
+ typedef linear_congruential<unsigned long, 48271, 0, 2147483647> minstd_rand;
+
+
+ /**
+ * A generalized feedback shift register discrete random number generator.
+ *
+ * This algorithm avoids multiplication and division and is designed to be
+ * friendly to a pipelined architecture. If the parameters are chosen
+ * correctly, this generator will produce numbers with a very long period and
+ * fairly good apparent entropy, although still not cryptographically strong.
+ *
+ * The best way to use this generator is with the predefined mt19937 class.
+ *
+ * This algorithm was originally invented by Makoto Matsumoto and
+ * Takuji Nishimura.
+ *
+ * @var word_size The number of bits in each element of the state vector.
+ * @var state_size The degree of recursion.
+ * @var shift_size The period parameter.
+ * @var mask_bits The separation point bit index.
+ * @var parameter_a The last row of the twist matrix.
+ * @var output_u The first right-shift tempering matrix parameter.
+ * @var output_s The first left-shift tempering matrix parameter.
+ * @var output_b The first left-shift tempering matrix mask.
+ * @var output_t The second left-shift tempering matrix parameter.
+ * @var output_c The second left-shift tempering matrix mask.
+ * @var output_l The second right-shift tempering matrix parameter.
+ */
+ template<class _UIntType, int __w, int __n, int __m, int __r,
+ _UIntType __a, int __u, int __s, _UIntType __b, int __t,
+ _UIntType __c, int __l>
+ class mersenne_twister
+ {
+ __glibcxx_class_requires(_UIntType, _UnsignedIntegerConcept)
+
+ public:
+ // types
+ typedef _UIntType result_type;
+
+ // parameter values
+ static const int word_size = __w;
+ static const int state_size = __n;
+ static const int shift_size = __m;
+ static const int mask_bits = __r;
+ static const _UIntType parameter_a = __a;
+ static const int output_u = __u;
+ static const int output_s = __s;
+ static const _UIntType output_b = __b;
+ static const int output_t = __t;
+ static const _UIntType output_c = __c;
+ static const int output_l = __l;
+
+ // constructors and member function
+ mersenne_twister()
+ { seed(); }
+
+ explicit
+ mersenne_twister(unsigned long __value)
+ { seed(__value); }
+
+ template<class _Gen>
+ mersenne_twister(_Gen& __g)
+ { seed(__g); }
+
+ void
+ seed()
+ { seed(5489UL); }
+
+ void
+ seed(unsigned long __value);
+
+ template<class _Gen>
+ void
+ seed(_Gen& __g)
+ { seed(__g, typename is_fundamental<_Gen>::type()); }
+
+ result_type
+ min() const
+ { return 0; };
+
+ result_type
+ max() const
+ { return __detail::_Shift<_UIntType, __w>::__value - 1; }
+
+ result_type
+ operator()();
+
+ /**
+ * Compares two % mersenne_twister random number generator objects of
+ * the same type for equality.
+ *
+ * @param __lhs A % mersenne_twister random number generator object.
+ * @param __rhs Another % mersenne_twister random number generator
+ * object.
+ *
+ * @returns true if the two objects are equal, false otherwise.
+ */
+ friend bool
+ operator==(const mersenne_twister& __lhs,
+ const mersenne_twister& __rhs)
+ { return std::equal(__lhs._M_x, __lhs._M_x + state_size, __rhs._M_x); }
+
+ /**
+ * Compares two % mersenne_twister random number generator objects of
+ * the same type for inequality.
+ *
+ * @param __lhs A % mersenne_twister random number generator object.
+ * @param __rhs Another % mersenne_twister random number generator
+ * object.
+ *
+ * @returns true if the two objects are not equal, false otherwise.
+ */
+ friend bool
+ operator!=(const mersenne_twister& __lhs,
+ const mersenne_twister& __rhs)
+ { return !(__lhs == __rhs); }
+
+ /**
+ * Inserts the current state of a % mersenne_twister random number
+ * generator engine @p __x into the output stream @p __os.
+ *
+ * @param __os An output stream.
+ * @param __x A % mersenne_twister random number generator engine.
+ *
+ * @returns The output stream with the state of @p __x inserted or in
+ * an error state.
+ */
+ template<class _UIntType1, int __w1, int __n1, int __m1, int __r1,
+ _UIntType1 __a1, int __u1, int __s1, _UIntType1 __b1, int __t1,
+ _UIntType1 __c1, int __l1,
+ typename _CharT, typename _Traits>
+ friend std::basic_ostream<_CharT, _Traits>&
+ operator<<(std::basic_ostream<_CharT, _Traits>& __os,
+ const mersenne_twister<_UIntType1, __w1, __n1, __m1, __r1,
+ __a1, __u1, __s1, __b1, __t1, __c1, __l1>& __x);
+
+ /**
+ * Extracts the current state of a % mersenne_twister random number
+ * generator engine @p __x from the input stream @p __is.
+ *
+ * @param __is An input stream.
+ * @param __x A % mersenne_twister random number generator engine.
+ *
+ * @returns The input stream with the state of @p __x extracted or in
+ * an error state.
+ */
+ template<class _UIntType1, int __w1, int __n1, int __m1, int __r1,
+ _UIntType1 __a1, int __u1, int __s1, _UIntType1 __b1, int __t1,
+ _UIntType1 __c1, int __l1,
+ typename _CharT, typename _Traits>
+ friend std::basic_istream<_CharT, _Traits>&
+ operator>>(std::basic_istream<_CharT, _Traits>& __is,
+ mersenne_twister<_UIntType1, __w1, __n1, __m1, __r1,
+ __a1, __u1, __s1, __b1, __t1, __c1, __l1>& __x);
+
+ private:
+ template<class _Gen>
+ void
+ seed(_Gen& __g, true_type)
+ { return seed(static_cast<unsigned long>(__g)); }
+
+ template<class _Gen>
+ void
+ seed(_Gen& __g, false_type);
+
+ _UIntType _M_x[state_size];
+ int _M_p;
+ };
+
+ /**
+ * The classic Mersenne Twister.
+ *
+ * Reference:
+ * M. Matsumoto and T. Nishimura, "Mersenne Twister: A 623-Dimensionally
+ * Equidistributed Uniform Pseudo-Random Number Generator", ACM Transactions
+ * on Modeling and Computer Simulation, Vol. 8, No. 1, January 1998, pp 3-30.
+ */
+ typedef mersenne_twister<
+ unsigned long, 32, 624, 397, 31,
+ 0x9908b0dful, 11, 7,
+ 0x9d2c5680ul, 15,
+ 0xefc60000ul, 18
+ > mt19937;
+
+
+ /**
+ * @brief The Marsaglia-Zaman generator.
+ *
+ * This is a model of a Generalized Fibonacci discrete random number
+ * generator, sometimes referred to as the SWC generator.
+ *
+ * A discrete random number generator that produces pseudorandom
+ * numbers using @f$x_{i}\leftarrow(x_{i - s} - x_{i - r} -
+ * carry_{i-1}) \bmod m @f$.
+ *
+ * The size of the state is @f$ r @f$
+ * and the maximum period of the generator is @f$ m^r - m^s -1 @f$.
+ *
+ * N1688[4.13] says "the template parameter _IntType shall denote an integral
+ * type large enough to store values up to m."
+ *
+ * @var _M_x The state of the generator. This is a ring buffer.
+ * @var _M_carry The carry.
+ * @var _M_p Current index of x(i - r).
+ */
+ template<typename _IntType, _IntType __m, int __s, int __r>
+ class subtract_with_carry
+ {
+ __glibcxx_class_requires(_IntType, _IntegerConcept)
+
+ public:
+ /** The type of the generated random value. */
+ typedef _IntType result_type;
+
+ // parameter values
+ static const _IntType modulus = __m;
+ static const int long_lag = __r;
+ static const int short_lag = __s;
+
+ /**
+ * Constructs a default-initialized % subtract_with_carry random number
+ * generator.
+ */
+ subtract_with_carry()
+ { this->seed(); }
+
+ /**
+ * Constructs an explicitly seeded % subtract_with_carry random number
+ * generator.
+ */
+ explicit
+ subtract_with_carry(unsigned long __value)
+ { this->seed(__value); }
+
+ /**
+ * Constructs a %subtract_with_carry random number generator engine
+ * seeded from the generator function @p __g.
+ *
+ * @param __g The seed generator function.
+ */
+ template<class _Gen>
+ subtract_with_carry(_Gen& __g)
+ { this->seed(__g); }
+
+ /**
+ * Seeds the initial state @f$ x_0 @f$ of the random number generator.
+ *
+ * N1688[4.19] modifies this as follows. If @p __value == 0,
+ * sets value to 19780503. In any case, with a linear
+ * congruential generator lcg(i) having parameters @f$ m_{lcg} =
+ * 2147483563, a_{lcg} = 40014, c_{lcg} = 0, and lcg(0) = value
+ * @f$, sets @f$ x_{-r} \dots x_{-1} @f$ to @f$ lcg(1) \bmod m
+ * \dots lcg(r) \bmod m @f$ respectively. If @f$ x_{-1} = 0 @f$
+ * set carry to 1, otherwise sets carry to 0.
+ */
+ void
+ seed(unsigned long __value = 19780503);
+
+ /**
+ * Seeds the initial state @f$ x_0 @f$ of the % subtract_with_carry
+ * random number generator.
+ */
+ template<class _Gen>
+ void
+ seed(_Gen& __g)
+ { seed(__g, typename is_fundamental<_Gen>::type()); }
+
+ /**
+ * Gets the inclusive minimum value of the range of random integers
+ * returned by this generator.
+ */
+ result_type
+ min() const
+ { return 0; }
+
+ /**
+ * Gets the inclusive maximum value of the range of random integers
+ * returned by this generator.
+ */
+ result_type
+ max() const
+ { return this->modulus - 1; }
+
+ /**
+ * Gets the next random number in the sequence.
+ */
+ result_type
+ operator()();
+
+ /**
+ * Compares two % subtract_with_carry random number generator objects of
+ * the same type for equality.
+ *
+ * @param __lhs A % subtract_with_carry random number generator object.
+ * @param __rhs Another % subtract_with_carry random number generator
+ * object.
+ *
+ * @returns true if the two objects are equal, false otherwise.
+ */
+ friend bool
+ operator==(const subtract_with_carry& __lhs,
+ const subtract_with_carry& __rhs)
+ { return std::equal(__lhs._M_x, __lhs._M_x + long_lag, __rhs._M_x); }
+
+ /**
+ * Compares two % subtract_with_carry random number generator objects of
+ * the same type for inequality.
+ *
+ * @param __lhs A % subtract_with_carry random number generator object.
+ * @param __rhs Another % subtract_with_carry random number generator
+ * object.
+ *
+ * @returns true if the two objects are not equal, false otherwise.
+ */
+ friend bool
+ operator!=(const subtract_with_carry& __lhs,
+ const subtract_with_carry& __rhs)
+ { return !(__lhs == __rhs); }
+
+ /**
+ * Inserts the current state of a % subtract_with_carry random number
+ * generator engine @p __x into the output stream @p __os.
+ *
+ * @param __os An output stream.
+ * @param __x A % subtract_with_carry random number generator engine.
+ *
+ * @returns The output stream with the state of @p __x inserted or in
+ * an error state.
+ */
+ template<typename _IntType1, _IntType1 __m1, int __s1, int __r1,
+ typename _CharT, typename _Traits>
+ friend std::basic_ostream<_CharT, _Traits>&
+ operator<<(std::basic_ostream<_CharT, _Traits>& __os,
+ const subtract_with_carry<_IntType1, __m1, __s1,
+ __r1>& __x);
+
+ /**
+ * Extracts the current state of a % subtract_with_carry random number
+ * generator engine @p __x from the input stream @p __is.
+ *
+ * @param __is An input stream.
+ * @param __x A % subtract_with_carry random number generator engine.
+ *
+ * @returns The input stream with the state of @p __x extracted or in
+ * an error state.
+ */
+ template<typename _IntType1, _IntType1 __m1, int __s1, int __r1,
+ typename _CharT, typename _Traits>
+ friend std::basic_istream<_CharT, _Traits>&
+ operator>>(std::basic_istream<_CharT, _Traits>& __is,
+ subtract_with_carry<_IntType1, __m1, __s1, __r1>& __x);
+
+ private:
+ template<class _Gen>
+ void
+ seed(_Gen& __g, true_type)
+ { return seed(static_cast<unsigned long>(__g)); }
+
+ template<class _Gen>
+ void
+ seed(_Gen& __g, false_type);
+
+ typedef typename __gnu_cxx::__add_unsigned<_IntType>::__type _UIntType;
+
+ _UIntType _M_x[long_lag];
+ _UIntType _M_carry;
+ int _M_p;
+ };
+
+
+ /**
+ * @brief The Marsaglia-Zaman generator (floats version).
+ *
+ * @var _M_x The state of the generator. This is a ring buffer.
+ * @var _M_carry The carry.
+ * @var _M_p Current index of x(i - r).
+ * @var _M_npows Precomputed negative powers of 2.
+ */
+ template<typename _RealType, int __w, int __s, int __r>
+ class subtract_with_carry_01
+ {
+ public:
+ /** The type of the generated random value. */
+ typedef _RealType result_type;
+
+ // parameter values
+ static const int word_size = __w;
+ static const int long_lag = __r;
+ static const int short_lag = __s;
+
+ /**
+ * Constructs a default-initialized % subtract_with_carry_01 random
+ * number generator.
+ */
+ subtract_with_carry_01()
+ {
+ this->seed();
+ _M_initialize_npows();
+ }
+
+ /**
+ * Constructs an explicitly seeded % subtract_with_carry_01 random number
+ * generator.
+ */
+ explicit
+ subtract_with_carry_01(unsigned long __value)
+ {
+ this->seed(__value);
+ _M_initialize_npows();
+ }
+
+ /**
+ * Constructs a % subtract_with_carry_01 random number generator engine
+ * seeded from the generator function @p __g.
+ *
+ * @param __g The seed generator function.
+ */
+ template<class _Gen>
+ subtract_with_carry_01(_Gen& __g)
+ {
+ this->seed(__g);
+ _M_initialize_npows();
+ }
+
+ /**
+ * Seeds the initial state @f$ x_0 @f$ of the random number generator.
+ */
+ void
+ seed(unsigned long __value = 19780503);
+
+ /**
+ * Seeds the initial state @f$ x_0 @f$ of the % subtract_with_carry_01
+ * random number generator.
+ */
+ template<class _Gen>
+ void
+ seed(_Gen& __g)
+ { seed(__g, typename is_fundamental<_Gen>::type()); }
+
+ /**
+ * Gets the minimum value of the range of random floats
+ * returned by this generator.
+ */
+ result_type
+ min() const
+ { return 0.0; }
+
+ /**
+ * Gets the maximum value of the range of random floats
+ * returned by this generator.
+ */
+ result_type
+ max() const
+ { return 1.0; }
+
+ /**
+ * Gets the next random number in the sequence.
+ */
+ result_type
+ operator()();
+
+ /**
+ * Compares two % subtract_with_carry_01 random number generator objects
+ * of the same type for equality.
+ *
+ * @param __lhs A % subtract_with_carry_01 random number
+ * generator object.
+ * @param __rhs Another % subtract_with_carry_01 random number generator
+ * object.
+ *
+ * @returns true if the two objects are equal, false otherwise.
+ */
+ friend bool
+ operator==(const subtract_with_carry_01& __lhs,
+ const subtract_with_carry_01& __rhs)
+ {
+ for (int __i = 0; __i < long_lag; ++__i)
+ if (!std::equal(__lhs._M_x[__i], __lhs._M_x[__i] + __n,
+ __rhs._M_x[__i]))
+ return false;
+ return true;
+ }
+
+ /**
+ * Compares two % subtract_with_carry_01 random number generator objects
+ * of the same type for inequality.
+ *
+ * @param __lhs A % subtract_with_carry_01 random number
+ * generator object.
+ *
+ * @param __rhs Another % subtract_with_carry_01 random number generator
+ * object.
+ *
+ * @returns true if the two objects are not equal, false otherwise.
+ */
+ friend bool
+ operator!=(const subtract_with_carry_01& __lhs,
+ const subtract_with_carry_01& __rhs)
+ { return !(__lhs == __rhs); }
+
+ /**
+ * Inserts the current state of a % subtract_with_carry_01 random number
+ * generator engine @p __x into the output stream @p __os.
+ *
+ * @param __os An output stream.
+ * @param __x A % subtract_with_carry_01 random number generator engine.
+ *
+ * @returns The output stream with the state of @p __x inserted or in
+ * an error state.
+ */
+ template<typename _RealType1, int __w1, int __s1, int __r1,
+ typename _CharT, typename _Traits>
+ friend std::basic_ostream<_CharT, _Traits>&
+ operator<<(std::basic_ostream<_CharT, _Traits>& __os,
+ const subtract_with_carry_01<_RealType1, __w1, __s1,
+ __r1>& __x);
+
+ /**
+ * Extracts the current state of a % subtract_with_carry_01 random number
+ * generator engine @p __x from the input stream @p __is.
+ *
+ * @param __is An input stream.
+ * @param __x A % subtract_with_carry_01 random number generator engine.
+ *
+ * @returns The input stream with the state of @p __x extracted or in
+ * an error state.
+ */
+ template<typename _RealType1, int __w1, int __s1, int __r1,
+ typename _CharT, typename _Traits>
+ friend std::basic_istream<_CharT, _Traits>&
+ operator>>(std::basic_istream<_CharT, _Traits>& __is,
+ subtract_with_carry_01<_RealType1, __w1, __s1, __r1>& __x);
+
+ private:
+ template<class _Gen>
+ void
+ seed(_Gen& __g, true_type)
+ { return seed(static_cast<unsigned long>(__g)); }
+
+ template<class _Gen>
+ void
+ seed(_Gen& __g, false_type);
+
+ void
+ _M_initialize_npows();
+
+ static const int __n = (__w + 31) / 32;
+
+ typedef __detail::_UInt32Type _UInt32Type;
+ _UInt32Type _M_x[long_lag][__n];
+ _RealType _M_npows[__n];
+ _UInt32Type _M_carry;
+ int _M_p;
+ };
+
+ typedef subtract_with_carry_01<float, 24, 10, 24> ranlux_base_01;
+
+ // _GLIBCXX_RESOLVE_LIB_DEFECTS
+ // 508. Bad parameters for ranlux64_base_01.
+ typedef subtract_with_carry_01<double, 48, 5, 12> ranlux64_base_01;
+
+
+ /**
+ * Produces random numbers from some base engine by discarding blocks of
+ * data.
+ *
+ * 0 <= @p __r <= @p __p
+ */
+ template<class _UniformRandomNumberGenerator, int __p, int __r>
+ class discard_block
+ {
+ // __glibcxx_class_requires(typename base_type::result_type,
+ // ArithmeticTypeConcept)
+
+ public:
+ /** The type of the underlying generator engine. */
+ typedef _UniformRandomNumberGenerator base_type;
+ /** The type of the generated random value. */
+ typedef typename base_type::result_type result_type;
+
+ // parameter values
+ static const int block_size = __p;
+ static const int used_block = __r;
+
+ /**
+ * Constructs a default %discard_block engine.
+ *
+ * The underlying engine is default constructed as well.
+ */
+ discard_block()
+ : _M_n(0) { }
+
+ /**
+ * Copy constructs a %discard_block engine.
+ *
+ * Copies an existing base class random number generator.
+ * @param rng An existing (base class) engine object.
+ */
+ explicit
+ discard_block(const base_type& __rng)
+ : _M_b(__rng), _M_n(0) { }
+
+ /**
+ * Seed constructs a %discard_block engine.
+ *
+ * Constructs the underlying generator engine seeded with @p __s.
+ * @param __s A seed value for the base class engine.
+ */
+ explicit
+ discard_block(unsigned long __s)
+ : _M_b(__s), _M_n(0) { }
+
+ /**
+ * Generator construct a %discard_block engine.
+ *
+ * @param __g A seed generator function.
+ */
+ template<class _Gen>
+ discard_block(_Gen& __g)
+ : _M_b(__g), _M_n(0) { }
+
+ /**
+ * Reseeds the %discard_block object with the default seed for the
+ * underlying base class generator engine.
+ */
+ void seed()
+ {
+ _M_b.seed();
+ _M_n = 0;
+ }
+
+ /**
+ * Reseeds the %discard_block object with the given seed generator
+ * function.
+ * @param __g A seed generator function.
+ */
+ template<class _Gen>
+ void seed(_Gen& __g)
+ {
+ _M_b.seed(__g);
+ _M_n = 0;
+ }
+
+ /**
+ * Gets a const reference to the underlying generator engine object.
+ */
+ const base_type&
+ base() const
+ { return _M_b; }
+
+ /**
+ * Gets the minimum value in the generated random number range.
+ */
+ result_type
+ min() const
+ { return _M_b.min(); }
+
+ /**
+ * Gets the maximum value in the generated random number range.
+ */
+ result_type
+ max() const
+ { return _M_b.max(); }
+
+ /**
+ * Gets the next value in the generated random number sequence.
+ */
+ result_type
+ operator()();
+
+ /**
+ * Compares two %discard_block random number generator objects of
+ * the same type for equality.
+ *
+ * @param __lhs A %discard_block random number generator object.
+ * @param __rhs Another %discard_block random number generator
+ * object.
+ *
+ * @returns true if the two objects are equal, false otherwise.
+ */
+ friend bool
+ operator==(const discard_block& __lhs, const discard_block& __rhs)
+ { return (__lhs._M_b == __rhs._M_b) && (__lhs._M_n == __rhs._M_n); }
+
+ /**
+ * Compares two %discard_block random number generator objects of
+ * the same type for inequality.
+ *
+ * @param __lhs A %discard_block random number generator object.
+ * @param __rhs Another %discard_block random number generator
+ * object.
+ *
+ * @returns true if the two objects are not equal, false otherwise.
+ */
+ friend bool
+ operator!=(const discard_block& __lhs, const discard_block& __rhs)
+ { return !(__lhs == __rhs); }
+
+ /**
+ * Inserts the current state of a %discard_block random number
+ * generator engine @p __x into the output stream @p __os.
+ *
+ * @param __os An output stream.
+ * @param __x A %discard_block random number generator engine.
+ *
+ * @returns The output stream with the state of @p __x inserted or in
+ * an error state.
+ */
+ template<class _UniformRandomNumberGenerator1, int __p1, int __r1,
+ typename _CharT, typename _Traits>
+ friend std::basic_ostream<_CharT, _Traits>&
+ operator<<(std::basic_ostream<_CharT, _Traits>& __os,
+ const discard_block<_UniformRandomNumberGenerator1,
+ __p1, __r1>& __x);
+
+ /**
+ * Extracts the current state of a % subtract_with_carry random number
+ * generator engine @p __x from the input stream @p __is.
+ *
+ * @param __is An input stream.
+ * @param __x A %discard_block random number generator engine.
+ *
+ * @returns The input stream with the state of @p __x extracted or in
+ * an error state.
+ */
+ template<class _UniformRandomNumberGenerator1, int __p1, int __r1,
+ typename _CharT, typename _Traits>
+ friend std::basic_istream<_CharT, _Traits>&
+ operator>>(std::basic_istream<_CharT, _Traits>& __is,
+ discard_block<_UniformRandomNumberGenerator1,
+ __p1, __r1>& __x);
+
+ private:
+ base_type _M_b;
+ int _M_n;
+ };
+
+
+ /**
+ * James's luxury-level-3 integer adaptation of Luescher's generator.
+ */
+ typedef discard_block<
+ subtract_with_carry<unsigned long, (1UL << 24), 10, 24>,
+ 223,
+ 24
+ > ranlux3;
+
+ /**
+ * James's luxury-level-4 integer adaptation of Luescher's generator.
+ */
+ typedef discard_block<
+ subtract_with_carry<unsigned long, (1UL << 24), 10, 24>,
+ 389,
+ 24
+ > ranlux4;
+
+ typedef discard_block<
+ subtract_with_carry_01<float, 24, 10, 24>,
+ 223,
+ 24
+ > ranlux3_01;
+
+ typedef discard_block<
+ subtract_with_carry_01<float, 24, 10, 24>,
+ 389,
+ 24
+ > ranlux4_01;
+
+
+ /**
+ * A random number generator adaptor class that combines two random number
+ * generator engines into a single output sequence.
+ */
+ template<class _UniformRandomNumberGenerator1, int __s1,
+ class _UniformRandomNumberGenerator2, int __s2>
+ class xor_combine
+ {
+ // __glibcxx_class_requires(typename _UniformRandomNumberGenerator1::
+ // result_type, ArithmeticTypeConcept)
+ // __glibcxx_class_requires(typename _UniformRandomNumberGenerator2::
+ // result_type, ArithmeticTypeConcept)
+
+ public:
+ /** The type of the first underlying generator engine. */
+ typedef _UniformRandomNumberGenerator1 base1_type;
+ /** The type of the second underlying generator engine. */
+ typedef _UniformRandomNumberGenerator2 base2_type;
+
+ private:
+ typedef typename base1_type::result_type _Result_type1;
+ typedef typename base2_type::result_type _Result_type2;
+
+ public:
+ /** The type of the generated random value. */
+ typedef typename __gnu_cxx::__conditional_type<(sizeof(_Result_type1)
+ > sizeof(_Result_type2)),
+ _Result_type1, _Result_type2>::__type result_type;
+
+ // parameter values
+ static const int shift1 = __s1;
+ static const int shift2 = __s2;
+
+ // constructors and member function
+ xor_combine()
+ : _M_b1(), _M_b2()
+ { _M_initialize_max(); }
+
+ xor_combine(const base1_type& __rng1, const base2_type& __rng2)
+ : _M_b1(__rng1), _M_b2(__rng2)
+ { _M_initialize_max(); }
+
+ xor_combine(unsigned long __s)
+ : _M_b1(__s), _M_b2(__s + 1)
+ { _M_initialize_max(); }
+
+ template<class _Gen>
+ xor_combine(_Gen& __g)
+ : _M_b1(__g), _M_b2(__g)
+ { _M_initialize_max(); }
+
+ void
+ seed()
+ {
+ _M_b1.seed();
+ _M_b2.seed();
+ }
+
+ template<class _Gen>
+ void
+ seed(_Gen& __g)
+ {
+ _M_b1.seed(__g);
+ _M_b2.seed(__g);
+ }
+
+ const base1_type&
+ base1() const
+ { return _M_b1; }
+
+ const base2_type&
+ base2() const
+ { return _M_b2; }
+
+ result_type
+ min() const
+ { return 0; }
+
+ result_type
+ max() const
+ { return _M_max; }
+
+ /**
+ * Gets the next random number in the sequence.
+ */
+ // NB: Not exactly the TR1 formula, per N2079 instead.
+ result_type
+ operator()()
+ {
+ return ((result_type(_M_b1() - _M_b1.min()) << shift1)
+ ^ (result_type(_M_b2() - _M_b2.min()) << shift2));
+ }
+
+ /**
+ * Compares two %xor_combine random number generator objects of
+ * the same type for equality.
+ *
+ * @param __lhs A %xor_combine random number generator object.
+ * @param __rhs Another %xor_combine random number generator
+ * object.
+ *
+ * @returns true if the two objects are equal, false otherwise.
+ */
+ friend bool
+ operator==(const xor_combine& __lhs, const xor_combine& __rhs)
+ {
+ return (__lhs.base1() == __rhs.base1())
+ && (__lhs.base2() == __rhs.base2());
+ }
+
+ /**
+ * Compares two %xor_combine random number generator objects of
+ * the same type for inequality.
+ *
+ * @param __lhs A %xor_combine random number generator object.
+ * @param __rhs Another %xor_combine random number generator
+ * object.
+ *
+ * @returns true if the two objects are not equal, false otherwise.
+ */
+ friend bool
+ operator!=(const xor_combine& __lhs, const xor_combine& __rhs)
+ { return !(__lhs == __rhs); }
+
+ /**
+ * Inserts the current state of a %xor_combine random number
+ * generator engine @p __x into the output stream @p __os.
+ *
+ * @param __os An output stream.
+ * @param __x A %xor_combine random number generator engine.
+ *
+ * @returns The output stream with the state of @p __x inserted or in
+ * an error state.
+ */
+ template<class _UniformRandomNumberGenerator11, int __s11,
+ class _UniformRandomNumberGenerator21, int __s21,
+ typename _CharT, typename _Traits>
+ friend std::basic_ostream<_CharT, _Traits>&
+ operator<<(std::basic_ostream<_CharT, _Traits>& __os,
+ const xor_combine<_UniformRandomNumberGenerator11, __s11,
+ _UniformRandomNumberGenerator21, __s21>& __x);
+
+ /**
+ * Extracts the current state of a %xor_combine random number
+ * generator engine @p __x from the input stream @p __is.
+ *
+ * @param __is An input stream.
+ * @param __x A %xor_combine random number generator engine.
+ *
+ * @returns The input stream with the state of @p __x extracted or in
+ * an error state.
+ */
+ template<class _UniformRandomNumberGenerator11, int __s11,
+ class _UniformRandomNumberGenerator21, int __s21,
+ typename _CharT, typename _Traits>
+ friend std::basic_istream<_CharT, _Traits>&
+ operator>>(std::basic_istream<_CharT, _Traits>& __is,
+ xor_combine<_UniformRandomNumberGenerator11, __s11,
+ _UniformRandomNumberGenerator21, __s21>& __x);
+
+ private:
+ void
+ _M_initialize_max();
+
+ result_type
+ _M_initialize_max_aux(result_type, result_type, int);
+
+ base1_type _M_b1;
+ base2_type _M_b2;
+ result_type _M_max;
+ };
+
+
+ /**
+ * A standard interface to a platform-specific non-deterministic
+ * random number generator (if any are available).
+ */
+ class random_device
+ {
+ public:
+ // types
+ typedef unsigned int result_type;
+
+ // constructors, destructors and member functions
+
+#ifdef _GLIBCXX_USE_RANDOM_TR1
+
+ explicit
+ random_device(const std::string& __token = "/dev/urandom")
+ {
+ if ((__token != "/dev/urandom" && __token != "/dev/random")
+ || !(_M_file = std::fopen(__token.c_str(), "rb")))
+ std::__throw_runtime_error(__N("random_device::"
+ "random_device(const std::string&)"));
+ }
+
+ ~random_device()
+ { std::fclose(_M_file); }
+
+#else
+
+ explicit
+ random_device(const std::string& __token = "mt19937")
+ : _M_mt(_M_strtoul(__token)) { }
+
+ private:
+ static unsigned long
+ _M_strtoul(const std::string& __str)
+ {
+ unsigned long __ret = 5489UL;
+ if (__str != "mt19937")
+ {
+ const char* __nptr = __str.c_str();
+ char* __endptr;
+ __ret = std::strtoul(__nptr, &__endptr, 0);
+ if (*__nptr == '\0' || *__endptr != '\0')
+ std::__throw_runtime_error(__N("random_device::_M_strtoul"
+ "(const std::string&)"));
+ }
+ return __ret;
+ }
+
+ public:
+
+#endif
+
+ result_type
+ min() const
+ { return std::numeric_limits<result_type>::min(); }
+
+ result_type
+ max() const
+ { return std::numeric_limits<result_type>::max(); }
+
+ double
+ entropy() const
+ { return 0.0; }
+
+ result_type
+ operator()()
+ {
+#ifdef _GLIBCXX_USE_RANDOM_TR1
+ result_type __ret;
+ std::fread(reinterpret_cast<void*>(&__ret), sizeof(result_type),
+ 1, _M_file);
+ return __ret;
+#else
+ return _M_mt();
+#endif
+ }
+
+ private:
+ random_device(const random_device&);
+ void operator=(const random_device&);
+
+#ifdef _GLIBCXX_USE_RANDOM_TR1
+ FILE* _M_file;
+#else
+ mt19937 _M_mt;
+#endif
+ };
+
+ /* @} */ // group tr1_random_generators
+
+ /**
+ * @defgroup tr1_random_distributions Random Number Distributions
+ * @ingroup tr1_random
+ * @{
+ */
+
+ /**
+ * @defgroup tr1_random_distributions_discrete Discrete Distributions
+ * @ingroup tr1_random_distributions
+ * @{
+ */
+
+ /**
+ * @brief Uniform discrete distribution for random numbers.
+ * A discrete random distribution on the range @f$[min, max]@f$ with equal
+ * probability throughout the range.
+ */
+ template<typename _IntType = int>
+ class uniform_int
+ {
+ __glibcxx_class_requires(_IntType, _IntegerConcept)
+
+ public:
+ /** The type of the parameters of the distribution. */
+ typedef _IntType input_type;
+ /** The type of the range of the distribution. */
+ typedef _IntType result_type;
+
+ public:
+ /**
+ * Constructs a uniform distribution object.
+ */
+ explicit
+ uniform_int(_IntType __min = 0, _IntType __max = 9)
+ : _M_min(__min), _M_max(__max)
+ {
+ _GLIBCXX_DEBUG_ASSERT(_M_min <= _M_max);
+ }
+
+ /**
+ * Gets the inclusive lower bound of the distribution range.
+ */
+ result_type
+ min() const
+ { return _M_min; }
+
+ /**
+ * Gets the inclusive upper bound of the distribution range.
+ */
+ result_type
+ max() const
+ { return _M_max; }
+
+ /**
+ * Resets the distribution state.
+ *
+ * Does nothing for the uniform integer distribution.
+ */
+ void
+ reset() { }
+
+ /**
+ * Gets a uniformly distributed random number in the range
+ * @f$(min, max)@f$.
+ */
+ template<typename _UniformRandomNumberGenerator>
+ result_type
+ operator()(_UniformRandomNumberGenerator& __urng)
+ {
+ typedef typename _UniformRandomNumberGenerator::result_type
+ _UResult_type;
+ return _M_call(__urng, _M_min, _M_max,
+ typename is_integral<_UResult_type>::type());
+ }
+
+ /**
+ * Gets a uniform random number in the range @f$[0, n)@f$.
+ *
+ * This function is aimed at use with std::random_shuffle.
+ */
+ template<typename _UniformRandomNumberGenerator>
+ result_type
+ operator()(_UniformRandomNumberGenerator& __urng, result_type __n)
+ {
+ typedef typename _UniformRandomNumberGenerator::result_type
+ _UResult_type;
+ return _M_call(__urng, 0, __n - 1,
+ typename is_integral<_UResult_type>::type());
+ }
+
+ /**
+ * Inserts a %uniform_int random number distribution @p __x into the
+ * output stream @p os.
+ *
+ * @param __os An output stream.
+ * @param __x A %uniform_int random number distribution.
+ *
+ * @returns The output stream with the state of @p __x inserted or in
+ * an error state.
+ */
+ template<typename _IntType1, typename _CharT, typename _Traits>
+ friend std::basic_ostream<_CharT, _Traits>&
+ operator<<(std::basic_ostream<_CharT, _Traits>& __os,
+ const uniform_int<_IntType1>& __x);
+
+ /**
+ * Extracts a %uniform_int random number distribution
+ * @p __x from the input stream @p __is.
+ *
+ * @param __is An input stream.
+ * @param __x A %uniform_int random number generator engine.
+ *
+ * @returns The input stream with @p __x extracted or in an error state.
+ */
+ template<typename _IntType1, typename _CharT, typename _Traits>
+ friend std::basic_istream<_CharT, _Traits>&
+ operator>>(std::basic_istream<_CharT, _Traits>& __is,
+ uniform_int<_IntType1>& __x);
+
+ private:
+ template<typename _UniformRandomNumberGenerator>
+ result_type
+ _M_call(_UniformRandomNumberGenerator& __urng,
+ result_type __min, result_type __max, true_type);
+
+ template<typename _UniformRandomNumberGenerator>
+ result_type
+ _M_call(_UniformRandomNumberGenerator& __urng,
+ result_type __min, result_type __max, false_type)
+ {
+ return result_type((__urng() - __urng.min())
+ / (__urng.max() - __urng.min())
+ * (__max - __min + 1)) + __min;
+ }
+
+ _IntType _M_min;
+ _IntType _M_max;
+ };
+
+
+ /**
+ * @brief A Bernoulli random number distribution.
+ *
+ * Generates a sequence of true and false values with likelihood @f$ p @f$
+ * that true will come up and @f$ (1 - p) @f$ that false will appear.
+ */
+ class bernoulli_distribution
+ {
+ public:
+ typedef int input_type;
+ typedef bool result_type;
+
+ public:
+ /**
+ * Constructs a Bernoulli distribution with likelihood @p p.
+ *
+ * @param __p [IN] The likelihood of a true result being returned. Must
+ * be in the interval @f$ [0, 1] @f$.
+ */
+ explicit
+ bernoulli_distribution(double __p = 0.5)
+ : _M_p(__p)
+ {
+ _GLIBCXX_DEBUG_ASSERT((_M_p >= 0.0) && (_M_p <= 1.0));
+ }
+
+ /**
+ * Gets the @p p parameter of the distribution.
+ */
+ double
+ p() const
+ { return _M_p; }
+
+ /**
+ * Resets the distribution state.
+ *
+ * Does nothing for a Bernoulli distribution.
+ */
+ void
+ reset() { }
+
+ /**
+ * Gets the next value in the Bernoullian sequence.
+ */
+ template<class _UniformRandomNumberGenerator>
+ result_type
+ operator()(_UniformRandomNumberGenerator& __urng)
+ {
+ if ((__urng() - __urng.min()) < _M_p * (__urng.max() - __urng.min()))
+ return true;
+ return false;
+ }
+
+ /**
+ * Inserts a %bernoulli_distribution random number distribution
+ * @p __x into the output stream @p __os.
+ *
+ * @param __os An output stream.
+ * @param __x A %bernoulli_distribution random number distribution.
+ *
+ * @returns The output stream with the state of @p __x inserted or in
+ * an error state.
+ */
+ template<typename _CharT, typename _Traits>
+ friend std::basic_ostream<_CharT, _Traits>&
+ operator<<(std::basic_ostream<_CharT, _Traits>& __os,
+ const bernoulli_distribution& __x);
+
+ /**
+ * Extracts a %bernoulli_distribution random number distribution
+ * @p __x from the input stream @p __is.
+ *
+ * @param __is An input stream.
+ * @param __x A %bernoulli_distribution random number generator engine.
+ *
+ * @returns The input stream with @p __x extracted or in an error state.
+ */
+ template<typename _CharT, typename _Traits>
+ friend std::basic_istream<_CharT, _Traits>&
+ operator>>(std::basic_istream<_CharT, _Traits>& __is,
+ bernoulli_distribution& __x)
+ { return __is >> __x._M_p; }
+
+ private:
+ double _M_p;
+ };
+
+
+ /**
+ * @brief A discrete geometric random number distribution.
+ *
+ * The formula for the geometric probability mass function is
+ * @f$ p(i) = (1 - p)p^{i-1} @f$ where @f$ p @f$ is the parameter of the
+ * distribution.
+ */
+ template<typename _IntType = int, typename _RealType = double>
+ class geometric_distribution
+ {
+ public:
+ // types
+ typedef _RealType input_type;
+ typedef _IntType result_type;
+
+ // constructors and member function
+ explicit
+ geometric_distribution(const _RealType& __p = _RealType(0.5))
+ : _M_p(__p)
+ {
+ _GLIBCXX_DEBUG_ASSERT((_M_p > 0.0) && (_M_p < 1.0));
+ _M_initialize();
+ }
+
+ /**
+ * Gets the distribution parameter @p p.
+ */
+ _RealType
+ p() const
+ { return _M_p; }
+
+ void
+ reset() { }
+
+ template<class _UniformRandomNumberGenerator>
+ result_type
+ operator()(_UniformRandomNumberGenerator& __urng);
+
+ /**
+ * Inserts a %geometric_distribution random number distribution
+ * @p __x into the output stream @p __os.
+ *
+ * @param __os An output stream.
+ * @param __x A %geometric_distribution random number distribution.
+ *
+ * @returns The output stream with the state of @p __x inserted or in
+ * an error state.
+ */
+ template<typename _IntType1, typename _RealType1,
+ typename _CharT, typename _Traits>
+ friend std::basic_ostream<_CharT, _Traits>&
+ operator<<(std::basic_ostream<_CharT, _Traits>& __os,
+ const geometric_distribution<_IntType1, _RealType1>& __x);
+
+ /**
+ * Extracts a %geometric_distribution random number distribution
+ * @p __x from the input stream @p __is.
+ *
+ * @param __is An input stream.
+ * @param __x A %geometric_distribution random number generator engine.
+ *
+ * @returns The input stream with @p __x extracted or in an error state.
+ */
+ template<typename _CharT, typename _Traits>
+ friend std::basic_istream<_CharT, _Traits>&
+ operator>>(std::basic_istream<_CharT, _Traits>& __is,
+ geometric_distribution& __x)
+ {
+ __is >> __x._M_p;
+ __x._M_initialize();
+ return __is;
+ }
+
+ private:
+ void
+ _M_initialize()
+ { _M_log_p = std::log(_M_p); }
+
+ _RealType _M_p;
+ _RealType _M_log_p;
+ };
+
+
+ template<typename _RealType>
+ class normal_distribution;
+
+ /**
+ * @brief A discrete Poisson random number distribution.
+ *
+ * The formula for the Poisson probability mass function is
+ * @f$ p(i) = \frac{mean^i}{i!} e^{-mean} @f$ where @f$ mean @f$ is the
+ * parameter of the distribution.
+ */
+ template<typename _IntType = int, typename _RealType = double>
+ class poisson_distribution
+ {
+ public:
+ // types
+ typedef _RealType input_type;
+ typedef _IntType result_type;
+
+ // constructors and member function
+ explicit
+ poisson_distribution(const _RealType& __mean = _RealType(1))
+ : _M_mean(__mean), _M_nd()
+ {
+ _GLIBCXX_DEBUG_ASSERT(_M_mean > 0.0);
+ _M_initialize();
+ }
+
+ /**
+ * Gets the distribution parameter @p mean.
+ */
+ _RealType
+ mean() const
+ { return _M_mean; }
+
+ void
+ reset()
+ { _M_nd.reset(); }
+
+ template<class _UniformRandomNumberGenerator>
+ result_type
+ operator()(_UniformRandomNumberGenerator& __urng);
+
+ /**
+ * Inserts a %poisson_distribution random number distribution
+ * @p __x into the output stream @p __os.
+ *
+ * @param __os An output stream.
+ * @param __x A %poisson_distribution random number distribution.
+ *
+ * @returns The output stream with the state of @p __x inserted or in
+ * an error state.
+ */
+ template<typename _IntType1, typename _RealType1,
+ typename _CharT, typename _Traits>
+ friend std::basic_ostream<_CharT, _Traits>&
+ operator<<(std::basic_ostream<_CharT, _Traits>& __os,
+ const poisson_distribution<_IntType1, _RealType1>& __x);
+
+ /**
+ * Extracts a %poisson_distribution random number distribution
+ * @p __x from the input stream @p __is.
+ *
+ * @param __is An input stream.
+ * @param __x A %poisson_distribution random number generator engine.
+ *
+ * @returns The input stream with @p __x extracted or in an error state.
+ */
+ template<typename _IntType1, typename _RealType1,
+ typename _CharT, typename _Traits>
+ friend std::basic_istream<_CharT, _Traits>&
+ operator>>(std::basic_istream<_CharT, _Traits>& __is,
+ poisson_distribution<_IntType1, _RealType1>& __x);
+
+ private:
+ void
+ _M_initialize();
+
+ // NB: Unused when _GLIBCXX_USE_C99_MATH_TR1 is undefined.
+ normal_distribution<_RealType> _M_nd;
+
+ _RealType _M_mean;
+
+ // Hosts either log(mean) or the threshold of the simple method.
+ _RealType _M_lm_thr;
+#if _GLIBCXX_USE_C99_MATH_TR1
+ _RealType _M_lfm, _M_sm, _M_d, _M_scx, _M_1cx, _M_c2b, _M_cb;
+#endif
+ };
+
+
+ /**
+ * @brief A discrete binomial random number distribution.
+ *
+ * The formula for the binomial probability mass function is
+ * @f$ p(i) = \binom{n}{i} p^i (1 - p)^{t - i} @f$ where @f$ t @f$
+ * and @f$ p @f$ are the parameters of the distribution.
+ */
+ template<typename _IntType = int, typename _RealType = double>
+ class binomial_distribution
+ {
+ public:
+ // types
+ typedef _RealType input_type;
+ typedef _IntType result_type;
+
+ // constructors and member function
+ explicit
+ binomial_distribution(_IntType __t = 1,
+ const _RealType& __p = _RealType(0.5))
+ : _M_t(__t), _M_p(__p), _M_nd()
+ {
+ _GLIBCXX_DEBUG_ASSERT((_M_t >= 0) && (_M_p >= 0.0) && (_M_p <= 1.0));
+ _M_initialize();
+ }
+
+ /**
+ * Gets the distribution @p t parameter.
+ */
+ _IntType
+ t() const
+ { return _M_t; }
+
+ /**
+ * Gets the distribution @p p parameter.
+ */
+ _RealType
+ p() const
+ { return _M_p; }
+
+ void
+ reset()
+ { _M_nd.reset(); }
+
+ template<class _UniformRandomNumberGenerator>
+ result_type
+ operator()(_UniformRandomNumberGenerator& __urng);
+
+ /**
+ * Inserts a %binomial_distribution random number distribution
+ * @p __x into the output stream @p __os.
+ *
+ * @param __os An output stream.
+ * @param __x A %binomial_distribution random number distribution.
+ *
+ * @returns The output stream with the state of @p __x inserted or in
+ * an error state.
+ */
+ template<typename _IntType1, typename _RealType1,
+ typename _CharT, typename _Traits>
+ friend std::basic_ostream<_CharT, _Traits>&
+ operator<<(std::basic_ostream<_CharT, _Traits>& __os,
+ const binomial_distribution<_IntType1, _RealType1>& __x);
+
+ /**
+ * Extracts a %binomial_distribution random number distribution
+ * @p __x from the input stream @p __is.
+ *
+ * @param __is An input stream.
+ * @param __x A %binomial_distribution random number generator engine.
+ *
+ * @returns The input stream with @p __x extracted or in an error state.
+ */
+ template<typename _IntType1, typename _RealType1,
+ typename _CharT, typename _Traits>
+ friend std::basic_istream<_CharT, _Traits>&
+ operator>>(std::basic_istream<_CharT, _Traits>& __is,
+ binomial_distribution<_IntType1, _RealType1>& __x);
+
+ private:
+ void
+ _M_initialize();
+
+ template<class _UniformRandomNumberGenerator>
+ result_type
+ _M_waiting(_UniformRandomNumberGenerator& __urng, _IntType __t);
+
+ // NB: Unused when _GLIBCXX_USE_C99_MATH_TR1 is undefined.
+ normal_distribution<_RealType> _M_nd;
+
+ _RealType _M_q;
+#if _GLIBCXX_USE_C99_MATH_TR1
+ _RealType _M_d1, _M_d2, _M_s1, _M_s2, _M_c,
+ _M_a1, _M_a123, _M_s, _M_lf, _M_lp1p;
+#endif
+ _RealType _M_p;
+ _IntType _M_t;
+
+ bool _M_easy;
+ };
+
+ /* @} */ // group tr1_random_distributions_discrete
+
+ /**
+ * @defgroup tr1_random_distributions_continuous Continuous Distributions
+ * @ingroup tr1_random_distributions
+ * @{
+ */
+
+ /**
+ * @brief Uniform continuous distribution for random numbers.
+ *
+ * A continuous random distribution on the range [min, max) with equal
+ * probability throughout the range. The URNG should be real-valued and
+ * deliver number in the range [0, 1).
+ */
+ template<typename _RealType = double>
+ class uniform_real
+ {
+ public:
+ // types
+ typedef _RealType input_type;
+ typedef _RealType result_type;
+
+ public:
+ /**
+ * Constructs a uniform_real object.
+ *
+ * @param __min [IN] The lower bound of the distribution.
+ * @param __max [IN] The upper bound of the distribution.
+ */
+ explicit
+ uniform_real(_RealType __min = _RealType(0),
+ _RealType __max = _RealType(1))
+ : _M_min(__min), _M_max(__max)
+ {
+ _GLIBCXX_DEBUG_ASSERT(_M_min <= _M_max);
+ }
+
+ result_type
+ min() const
+ { return _M_min; }
+
+ result_type
+ max() const
+ { return _M_max; }
+
+ void
+ reset() { }
+
+ template<class _UniformRandomNumberGenerator>
+ result_type
+ operator()(_UniformRandomNumberGenerator& __urng)
+ { return (__urng() * (_M_max - _M_min)) + _M_min; }
+
+ /**
+ * Inserts a %uniform_real random number distribution @p __x into the
+ * output stream @p __os.
+ *
+ * @param __os An output stream.
+ * @param __x A %uniform_real random number distribution.
+ *
+ * @returns The output stream with the state of @p __x inserted or in
+ * an error state.
+ */
+ template<typename _RealType1, typename _CharT, typename _Traits>
+ friend std::basic_ostream<_CharT, _Traits>&
+ operator<<(std::basic_ostream<_CharT, _Traits>& __os,
+ const uniform_real<_RealType1>& __x);
+
+ /**
+ * Extracts a %uniform_real random number distribution
+ * @p __x from the input stream @p __is.
+ *
+ * @param __is An input stream.
+ * @param __x A %uniform_real random number generator engine.
+ *
+ * @returns The input stream with @p __x extracted or in an error state.
+ */
+ template<typename _RealType1, typename _CharT, typename _Traits>
+ friend std::basic_istream<_CharT, _Traits>&
+ operator>>(std::basic_istream<_CharT, _Traits>& __is,
+ uniform_real<_RealType1>& __x);
+
+ private:
+ _RealType _M_min;
+ _RealType _M_max;
+ };
+
+
+ /**
+ * @brief An exponential continuous distribution for random numbers.
+ *
+ * The formula for the exponential probability mass function is
+ * @f$ p(x) = \lambda e^{-\lambda x} @f$.
+ *
+ * <table border=1 cellpadding=10 cellspacing=0>
+ * <caption align=top>Distribution Statistics</caption>
+ * <tr><td>Mean</td><td>@f$ \frac{1}{\lambda} @f$</td></tr>
+ * <tr><td>Median</td><td>@f$ \frac{\ln 2}{\lambda} @f$</td></tr>
+ * <tr><td>Mode</td><td>@f$ zero @f$</td></tr>
+ * <tr><td>Range</td><td>@f$[0, \infty]@f$</td></tr>
+ * <tr><td>Standard Deviation</td><td>@f$ \frac{1}{\lambda} @f$</td></tr>
+ * </table>
+ */
+ template<typename _RealType = double>
+ class exponential_distribution
+ {
+ public:
+ // types
+ typedef _RealType input_type;
+ typedef _RealType result_type;
+
+ public:
+ /**
+ * Constructs an exponential distribution with inverse scale parameter
+ * @f$ \lambda @f$.
+ */
+ explicit
+ exponential_distribution(const result_type& __lambda = result_type(1))
+ : _M_lambda(__lambda)
+ {
+ _GLIBCXX_DEBUG_ASSERT(_M_lambda > 0);
+ }
+
+ /**
+ * Gets the inverse scale parameter of the distribution.
+ */
+ _RealType
+ lambda() const
+ { return _M_lambda; }
+
+ /**
+ * Resets the distribution.
+ *
+ * Has no effect on exponential distributions.
+ */
+ void
+ reset() { }
+
+ template<class _UniformRandomNumberGenerator>
+ result_type
+ operator()(_UniformRandomNumberGenerator& __urng)
+ { return -std::log(__urng()) / _M_lambda; }
+
+ /**
+ * Inserts a %exponential_distribution random number distribution
+ * @p __x into the output stream @p __os.
+ *
+ * @param __os An output stream.
+ * @param __x A %exponential_distribution random number distribution.
+ *
+ * @returns The output stream with the state of @p __x inserted or in
+ * an error state.
+ */
+ template<typename _RealType1, typename _CharT, typename _Traits>
+ friend std::basic_ostream<_CharT, _Traits>&
+ operator<<(std::basic_ostream<_CharT, _Traits>& __os,
+ const exponential_distribution<_RealType1>& __x);
+
+ /**
+ * Extracts a %exponential_distribution random number distribution
+ * @p __x from the input stream @p __is.
+ *
+ * @param __is An input stream.
+ * @param __x A %exponential_distribution random number
+ * generator engine.
+ *
+ * @returns The input stream with @p __x extracted or in an error state.
+ */
+ template<typename _CharT, typename _Traits>
+ friend std::basic_istream<_CharT, _Traits>&
+ operator>>(std::basic_istream<_CharT, _Traits>& __is,
+ exponential_distribution& __x)
+ { return __is >> __x._M_lambda; }
+
+ private:
+ result_type _M_lambda;
+ };
+
+
+ /**
+ * @brief A normal continuous distribution for random numbers.
+ *
+ * The formula for the normal probability mass function is
+ * @f$ p(x) = \frac{1}{\sigma \sqrt{2 \pi}}
+ * e^{- \frac{{x - mean}^ {2}}{2 \sigma ^ {2}} } @f$.
+ */
+ template<typename _RealType = double>
+ class normal_distribution
+ {
+ public:
+ // types
+ typedef _RealType input_type;
+ typedef _RealType result_type;
+
+ public:
+ /**
+ * Constructs a normal distribution with parameters @f$ mean @f$ and
+ * @f$ \sigma @f$.
+ */
+ explicit
+ normal_distribution(const result_type& __mean = result_type(0),
+ const result_type& __sigma = result_type(1))
+ : _M_mean(__mean), _M_sigma(__sigma), _M_saved_available(false)
+ {
+ _GLIBCXX_DEBUG_ASSERT(_M_sigma > 0);
+ }
+
+ /**
+ * Gets the mean of the distribution.
+ */
+ _RealType
+ mean() const
+ { return _M_mean; }
+
+ /**
+ * Gets the @f$ \sigma @f$ of the distribution.
+ */
+ _RealType
+ sigma() const
+ { return _M_sigma; }
+
+ /**
+ * Resets the distribution.
+ */
+ void
+ reset()
+ { _M_saved_available = false; }
+
+ template<class _UniformRandomNumberGenerator>
+ result_type
+ operator()(_UniformRandomNumberGenerator& __urng);
+
+ /**
+ * Inserts a %normal_distribution random number distribution
+ * @p __x into the output stream @p __os.
+ *
+ * @param __os An output stream.
+ * @param __x A %normal_distribution random number distribution.
+ *
+ * @returns The output stream with the state of @p __x inserted or in
+ * an error state.
+ */
+ template<typename _RealType1, typename _CharT, typename _Traits>
+ friend std::basic_ostream<_CharT, _Traits>&
+ operator<<(std::basic_ostream<_CharT, _Traits>& __os,
+ const normal_distribution<_RealType1>& __x);
+
+ /**
+ * Extracts a %normal_distribution random number distribution
+ * @p __x from the input stream @p __is.
+ *
+ * @param __is An input stream.
+ * @param __x A %normal_distribution random number generator engine.
+ *
+ * @returns The input stream with @p __x extracted or in an error state.
+ */
+ template<typename _RealType1, typename _CharT, typename _Traits>
+ friend std::basic_istream<_CharT, _Traits>&
+ operator>>(std::basic_istream<_CharT, _Traits>& __is,
+ normal_distribution<_RealType1>& __x);
+
+ private:
+ result_type _M_mean;
+ result_type _M_sigma;
+ result_type _M_saved;
+ bool _M_saved_available;
+ };
+
+
+ /**
+ * @brief A gamma continuous distribution for random numbers.
+ *
+ * The formula for the gamma probability mass function is
+ * @f$ p(x) = \frac{1}{\Gamma(\alpha)} x^{\alpha - 1} e^{-x} @f$.
+ */
+ template<typename _RealType = double>
+ class gamma_distribution
+ {
+ public:
+ // types
+ typedef _RealType input_type;
+ typedef _RealType result_type;
+
+ public:
+ /**
+ * Constructs a gamma distribution with parameters @f$ \alpha @f$.
+ */
+ explicit
+ gamma_distribution(const result_type& __alpha_val = result_type(1))
+ : _M_alpha(__alpha_val)
+ {
+ _GLIBCXX_DEBUG_ASSERT(_M_alpha > 0);
+ _M_initialize();
+ }
+
+ /**
+ * Gets the @f$ \alpha @f$ of the distribution.
+ */
+ _RealType
+ alpha() const
+ { return _M_alpha; }
+
+ /**
+ * Resets the distribution.
+ */
+ void
+ reset() { }
+
+ template<class _UniformRandomNumberGenerator>
+ result_type
+ operator()(_UniformRandomNumberGenerator& __urng);
+
+ /**
+ * Inserts a %gamma_distribution random number distribution
+ * @p __x into the output stream @p __os.
+ *
+ * @param __os An output stream.
+ * @param __x A %gamma_distribution random number distribution.
+ *
+ * @returns The output stream with the state of @p __x inserted or in
+ * an error state.
+ */
+ template<typename _RealType1, typename _CharT, typename _Traits>
+ friend std::basic_ostream<_CharT, _Traits>&
+ operator<<(std::basic_ostream<_CharT, _Traits>& __os,
+ const gamma_distribution<_RealType1>& __x);
+
+ /**
+ * Extracts a %gamma_distribution random number distribution
+ * @p __x from the input stream @p __is.
+ *
+ * @param __is An input stream.
+ * @param __x A %gamma_distribution random number generator engine.
+ *
+ * @returns The input stream with @p __x extracted or in an error state.
+ */
+ template<typename _CharT, typename _Traits>
+ friend std::basic_istream<_CharT, _Traits>&
+ operator>>(std::basic_istream<_CharT, _Traits>& __is,
+ gamma_distribution& __x)
+ {
+ __is >> __x._M_alpha;
+ __x._M_initialize();
+ return __is;
+ }
+
+ private:
+ void
+ _M_initialize();
+
+ result_type _M_alpha;
+
+ // Hosts either lambda of GB or d of modified Vaduva's.
+ result_type _M_l_d;
+ };
+
+ /* @} */ // group tr1_random_distributions_continuous
+ /* @} */ // group tr1_random_distributions
+ /* @} */ // group tr1_random
+
+_GLIBCXX_END_NAMESPACE_TR1
+}
+
+#include <tr1_impl/random.tcc>
projects / msp430-gcc.git / blobdiff