1//===----------------------------------------------------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is dual licensed under the MIT and the University of Illinois Open
6// Source Licenses. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10// <random>
11
12// template<class Engine, size_t w, class UIntType>
13// class independent_bits_engine
14
15// result_type operator()();
16
17#include <random>
18#include <cassert>
19
20template <class UIntType, UIntType Min, UIntType Max>
21class rand1
22{
23public:
24    // types
25    typedef UIntType result_type;
26
27private:
28    result_type x_;
29
30    static_assert(Min < Max, "rand1 invalid parameters");
31public:
32
33#ifdef _LIBCPP_HAS_NO_CONSTEXPR
34    // Workaround for lack of constexpr in C++03
35    static const result_type _Min = Min;
36    static const result_type _Max = Max;
37#endif
38
39    static _LIBCPP_CONSTEXPR result_type min() {return Min;}
40    static _LIBCPP_CONSTEXPR result_type max() {return Max;}
41
42    explicit rand1(result_type sd = Min) : x_(sd)
43    {
44        if (x_ > Max)
45            x_ = Max;
46    }
47
48    result_type operator()()
49    {
50        result_type r = x_;
51        if (x_ < Max)
52            ++x_;
53        else
54            x_ = Min;
55        return r;
56    }
57};
58
59void
60test1()
61{
62   typedef std::independent_bits_engine<rand1<unsigned, 0, 10>, 16, unsigned> E;
63
64    E e;
65    assert(e() == 6958);
66}
67
68void
69test2()
70{
71    typedef std::independent_bits_engine<rand1<unsigned, 0, 100>, 16, unsigned> E;
72
73    E e;
74    assert(e() == 66);
75}
76
77void
78test3()
79{
80    typedef std::independent_bits_engine<rand1<unsigned, 0, 0xFFFFFFFF>, 32, unsigned> E;
81
82    E e(5);
83    assert(e() == 5);
84}
85
86void
87test4()
88{
89    typedef std::independent_bits_engine<rand1<unsigned, 0, 0xFFFFFFFF>, 7, unsigned> E;
90
91    E e(129);
92    assert(e() == 1);
93}
94
95void
96test5()
97{
98    typedef std::independent_bits_engine<rand1<unsigned, 2, 3>, 1, unsigned> E;
99
100    E e(6);
101    assert(e() == 1);
102}
103
104void
105test6()
106{
107    typedef std::independent_bits_engine<rand1<unsigned, 2, 3>, 11, unsigned> E;
108
109    E e(6);
110    assert(e() == 1365);
111}
112
113void
114test7()
115{
116    typedef std::independent_bits_engine<rand1<unsigned, 2, 3>, 32, unsigned> E;
117
118    E e(6);
119    assert(e() == 2863311530u);
120}
121
122void
123test8()
124{
125    typedef std::independent_bits_engine<std::mt19937, 64, unsigned long long> E;
126
127    E e(6);
128    assert(e() == 16470362623952407241ull);
129}
130
131int main()
132{
133    test1();
134    test2();
135    test3();
136    test4();
137    test5();
138    test6();
139    test7();
140    test8();
141}
142