boost_range 0.1.0

Boost C++ library boost_range packaged using Zanbil
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141

//  Copyright Neil Groves 2009. Use, modification and
//  distribution is subject to 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)
//
//
// For more information, see http://www.boost.org/libs/range/
//
#ifndef BOOST_RANGE_ALGORITHM_RANDOM_SHUFFLE_HPP_INCLUDED
#define BOOST_RANGE_ALGORITHM_RANDOM_SHUFFLE_HPP_INCLUDED

#include <boost/concept_check.hpp>
#include <boost/range/begin.hpp>
#include <boost/range/end.hpp>
#include <boost/range/concepts.hpp>
#include <algorithm>
#ifdef BOOST_NO_CXX98_RANDOM_SHUFFLE
#include <cstdlib>
#endif

namespace boost
{
    namespace range
    {

        namespace detail
        {
#ifdef BOOST_NO_CXX98_RANDOM_SHUFFLE

// wrap std::rand as UniformRandomBitGenerator
struct wrap_rand
{
    typedef unsigned int result_type;

    static BOOST_CONSTEXPR result_type (min)()
    {
        return 0;
    }

    static BOOST_CONSTEXPR result_type (max)()
    {
        return RAND_MAX;
    }

    result_type operator()()
    {
        return std::rand();
    }
};

template< class RandomIt >
inline void random_shuffle(RandomIt first, RandomIt last)
{
    std::shuffle(first, last, wrap_rand());
}

// wrap Generator as UniformRandomBitGenerator
template< class Generator >
struct wrap_generator
{
    typedef unsigned int result_type;
    static const int max_arg = ((0u - 1u) >> 2) + 1;
    Generator& g;

    wrap_generator(Generator& gen) : g(gen) {}

    static BOOST_CONSTEXPR result_type (min)()
    {
        return 0;
    }

    static BOOST_CONSTEXPR result_type (max)()
    {
        return max_arg - 1;
    }

    result_type operator()()
    {
        return static_cast<result_type>(g(max_arg));
    }
};

template< class RandomIt, class Generator >
inline void random_shuffle(RandomIt first, RandomIt last, Generator& gen)
{
    std::shuffle(first, last, wrap_generator< Generator >(gen));
}

#else
    
using std::random_shuffle;

#endif  
        } // namespace detail

/// \brief template function random_shuffle
///
/// range-based version of the random_shuffle std algorithm
///
/// \pre RandomAccessRange is a model of the RandomAccessRangeConcept
/// \pre Generator is a model of the UnaryFunctionConcept
template<class RandomAccessRange>
inline RandomAccessRange& random_shuffle(RandomAccessRange& rng)
{
    BOOST_RANGE_CONCEPT_ASSERT(( RandomAccessRangeConcept<RandomAccessRange> ));
    detail::random_shuffle(boost::begin(rng), boost::end(rng));
    return rng;
}

/// \overload
template<class RandomAccessRange>
inline const RandomAccessRange& random_shuffle(const RandomAccessRange& rng)
{
    BOOST_RANGE_CONCEPT_ASSERT(( RandomAccessRangeConcept<const RandomAccessRange> ));
    detail::random_shuffle(boost::begin(rng), boost::end(rng));
    return rng;
}

/// \overload
template<class RandomAccessRange, class Generator>
inline RandomAccessRange& random_shuffle(RandomAccessRange& rng, Generator& gen)
{
    BOOST_RANGE_CONCEPT_ASSERT(( RandomAccessRangeConcept<RandomAccessRange> ));
    detail::random_shuffle(boost::begin(rng), boost::end(rng), gen);
    return rng;
}

/// \overload
template<class RandomAccessRange, class Generator>
inline const RandomAccessRange& random_shuffle(const RandomAccessRange& rng, Generator& gen)
{
    BOOST_RANGE_CONCEPT_ASSERT(( RandomAccessRangeConcept<const RandomAccessRange> ));
    detail::random_shuffle(boost::begin(rng), boost::end(rng), gen);
    return rng;
}

    } // namespace range
    using range::random_shuffle;
} // namespace boost

#endif // include guard