| /* boost random/random_number_generator.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: random_number_generator.hpp 60755 2010-03-22 00:45:06Z steven_watanabe $ |
| * |
| * Revision history |
| * 2001-02-18 moved to individual header files |
| */ |
| |
| #ifndef BOOST_RANDOM_RANDOM_NUMBER_GENERATOR_HPP |
| #define BOOST_RANDOM_RANDOM_NUMBER_GENERATOR_HPP |
| |
| #include <boost/config.hpp> |
| #include <boost/limits.hpp> |
| #include <boost/static_assert.hpp> |
| #include <boost/random/uniform_int.hpp> |
| #include <boost/random/variate_generator.hpp> |
| |
| namespace boost { |
| |
| /** |
| * Instantiations of class template random_number_generator model a |
| * RandomNumberGenerator (std:25.2.11 [lib.alg.random.shuffle]). On |
| * each invocation, it returns a uniformly distributed integer in |
| * the range [0..n). |
| * |
| * The template parameter IntType shall denote some integer-like value type. |
| */ |
| template<class UniformRandomNumberGenerator, class IntType = long> |
| class random_number_generator |
| { |
| public: |
| typedef UniformRandomNumberGenerator base_type; |
| typedef IntType argument_type; |
| typedef IntType result_type; |
| /** |
| * Constructs a random_number_generator functor with the given |
| * \uniform_random_number_generator as the underlying source of |
| * random numbers. |
| */ |
| random_number_generator(base_type& rng) : _rng(rng) |
| { |
| #ifndef BOOST_NO_LIMITS_COMPILE_TIME_CONSTANTS |
| BOOST_STATIC_ASSERT(std::numeric_limits<result_type>::is_integer); |
| #endif |
| } |
| // compiler-generated copy ctor is fine |
| // assignment is disallowed because there is a reference member |
| |
| /** |
| * Returns a value in the range [0, n) |
| */ |
| result_type operator()(argument_type n) |
| { |
| typedef uniform_int<IntType> dist_type; |
| return variate_generator<base_type&, dist_type>(_rng, dist_type(0, n-1))(); |
| } |
| |
| private: |
| base_type& _rng; |
| }; |
| |
| } // namespace boost |
| |
| #endif // BOOST_RANDOM_RANDOM_NUMBER_GENERATOR_HPP |