1/* boost random/detail/uniform_int_float.hpp header file
2 *
3 * Copyright Jens Maurer 2000-2001
4 * Copyright Steven Watanabe 2011
5 * Distributed under the Boost Software License, Version 1.0. (See
6 * accompanying file LICENSE_1_0.txt or copy at
7 * http://www.boost.org/LICENSE_1_0.txt)
8 *
9 * See http://www.boost.org for most recent version including documentation.
10 *
11 * $Id$
12 *
13 */
14
15#ifndef BOOST_RANDOM_DETAIL_UNIFORM_INT_FLOAT_HPP
16#define BOOST_RANDOM_DETAIL_UNIFORM_INT_FLOAT_HPP
17
18#include <boost/limits.hpp>
19#include <boost/config.hpp>
20#include <boost/integer.hpp>
21#include <boost/random/detail/config.hpp>
22#include <boost/random/detail/generator_bits.hpp>
23
24#include <boost/random/detail/disable_warnings.hpp>
25
26namespace boost {
27namespace random {
28namespace detail {
29
30template<class URNG>
31class uniform_int_float
32{
33public:
34 typedef URNG base_type;
35 typedef typename base_type::result_type base_result;
36
37 typedef typename boost::uint_t<
38 (std::numeric_limits<boost::uintmax_t>::digits <
39 std::numeric_limits<base_result>::digits)?
40 std::numeric_limits<boost::uintmax_t>::digits :
41 std::numeric_limits<base_result>::digits
42 >::fast result_type;
43
44 uniform_int_float(base_type& rng)
45 : _rng(rng) {}
46
47 static result_type min BOOST_PREVENT_MACRO_SUBSTITUTION ()
48 { return 0; }
49 static result_type max BOOST_PREVENT_MACRO_SUBSTITUTION ()
50 {
51 std::size_t digits = std::numeric_limits<result_type>::digits;
52 if(detail::generator_bits<URNG>::value() < digits) {
53 digits = detail::generator_bits<URNG>::value();
54 }
55 return (result_type(2) << (digits - 1)) - 1;
56 }
57 base_type& base() { return _rng; }
58 const base_type& base() const { return _rng; }
59
60 result_type operator()()
61 {
62 base_result range = static_cast<base_result>((max)())+1;
63 return static_cast<result_type>(_rng() * range);
64 }
65
66private:
67 base_type& _rng;
68};
69
70} // namespace detail
71} // namespace random
72} // namespace boost
73
74#include <boost/random/detail/enable_warnings.hpp>
75
76#endif // BOOST_RANDOM_DETAIL_UNIFORM_INT_FLOAT_HPP
77