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/assert.hpp>
20#include <boost/random/uniform_int_distribution.hpp>
21
22#include <boost/random/detail/disable_warnings.hpp>
23
24namespace boost {
25namespace random {
26
27/**
28 * Instantiations of class template random_number_generator model a
29 * RandomNumberGenerator (std:25.2.11 [lib.alg.random.shuffle]). On
30 * each invocation, it returns a uniformly distributed integer in
31 * the range [0..n).
32 *
33 * The template parameter IntType shall denote some integer-like value type.
34 */
35template<class URNG, class IntType = long>
36class random_number_generator
37{
38public:
39 typedef URNG base_type;
40 typedef IntType argument_type;
41 typedef IntType result_type;
42 /**
43 * Constructs a random_number_generator functor with the given
44 * \uniform_random_number_generator as the underlying source of
45 * random numbers.
46 */
47 random_number_generator(base_type& rng) : _rng(rng) {}
48
49 // compiler-generated copy ctor is fine
50 // assignment is disallowed because there is a reference member
51
52 /**
53 * Returns a value in the range [0, n)
54 */
55 result_type operator()(argument_type n)
56 {
57 BOOST_ASSERT(n > 0);
58 return uniform_int_distribution<IntType>(0, n-1)(_rng);
59 }
60
61private:
62 base_type& _rng;
63};
64
65} // namespace random
66
67using random::random_number_generator;
68
69} // namespace boost
70
71#include <boost/random/detail/enable_warnings.hpp>
72
73#endif // BOOST_RANDOM_RANDOM_NUMBER_GENERATOR_HPP
74