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			74 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
|   | /* 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. | ||
|  |  * | ||
|  |  * $Id$ | ||
|  |  * | ||
|  |  * 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/assert.hpp> | ||
|  | #include <boost/random/uniform_int_distribution.hpp> | ||
|  | 
 | ||
|  | #include <boost/random/detail/disable_warnings.hpp> | ||
|  | 
 | ||
|  | namespace boost { | ||
|  | namespace random { | ||
|  | 
 | ||
|  | /** | ||
|  |  * 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 URNG, class IntType = long> | ||
|  | class random_number_generator | ||
|  | { | ||
|  | public: | ||
|  |     typedef URNG 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) {} | ||
|  | 
 | ||
|  |     // 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) | ||
|  |     { | ||
|  |         BOOST_ASSERT(n > 0); | ||
|  |         return uniform_int_distribution<IntType>(0, n-1)(_rng); | ||
|  |     } | ||
|  | 
 | ||
|  | private: | ||
|  |     base_type& _rng; | ||
|  | }; | ||
|  | 
 | ||
|  | } // namespace random | ||
|  | 
 | ||
|  | using random::random_number_generator; | ||
|  | 
 | ||
|  | } // namespace boost | ||
|  | 
 | ||
|  | #include <boost/random/detail/enable_warnings.hpp> | ||
|  | 
 | ||
|  | #endif // BOOST_RANDOM_RANDOM_NUMBER_GENERATOR_HPP |