boost/random/random_number_generator.hpp

   1 /* boost random/random_number_generator.hpp header file
   2  *
   3  * Copyright Jens Maurer 2000-2001
   4  * Distributed under the Boost Software License, Version 1.0. (See
   5  * accompanying file LICENSE_1_0.txt or copy at
   6  * http://www.boost.org/LICENSE_1_0.txt)
   7  *
   8  * See http://www.boost.org for most recent version including documentation.
   9  *
  10  * $Id$
  11  *
  12  * Revision history
  13  *  2001-02-18  moved to individual header files
  14  */
  15
  16 #ifndef BOOST_RANDOM_RANDOM_NUMBER_GENERATOR_HPP
  17 #define BOOST_RANDOM_RANDOM_NUMBER_GENERATOR_HPP
  18
  19 #include <boost/config.hpp>
  20 #include <boost/limits.hpp>
  21 #include <boost/static_assert.hpp>
  22 #include <boost/random/uniform_int.hpp>
  23 #include <boost/random/variate_generator.hpp>
  24
  25 namespace boost {
  26
  27 // a model for RandomNumberGenerator std:25.2.11 [lib.alg.random.shuffle]
  28 template<class UniformRandomNumberGenerator, class IntType = long>
  29 class random_number_generator
  30 {
  31 public:
  32   typedef UniformRandomNumberGenerator base_type;
  33   typedef IntType argument_type;
  34   typedef IntType result_type;
  35   random_number_generator(base_type& rng) : _rng(rng)
  36   {
  37 #ifndef BOOST_NO_LIMITS_COMPILE_TIME_CONSTANTS
  38     BOOST_STATIC_ASSERT(std::numeric_limits<result_type>::is_integer);
  39 #endif
  40   }
  41   // compiler-generated copy ctor is fine
  42   // assignment is disallowed because there is a reference member
  43
  44   result_type operator()(argument_type n)
  45   {
  46     typedef uniform_int<IntType> dist_type;
  47     return variate_generator<base_type&, dist_type>(_rng, dist_type(0, n-1))();
  48   }
  49
  50 private:
  51   base_type& _rng;
  52 };
  53
  54 } // namespace boost
  55
  56 #endif // BOOST_RANDOM_RANDOM_NUMBER_GENERATOR_HPP