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
20 template <class UIntType, UIntType Min, UIntType Max>
21 class rand1
22 {
23 public:
24 // types
25 typedef UIntType result_type;
26
27 private:
28 result_type x_;
29
30 static_assert(Min < Max, "rand1 invalid parameters");
31 public:
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
min()39 static _LIBCPP_CONSTEXPR result_type min() {return Min;}
max()40 static _LIBCPP_CONSTEXPR result_type max() {return Max;}
41
rand1(result_type sd=Min)42 explicit rand1(result_type sd = Min) : x_(sd)
43 {
44 if (x_ > Max)
45 x_ = Max;
46 }
47
operator ()()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
59 void
test1()60 test1()
61 {
62 typedef std::independent_bits_engine<rand1<unsigned, 0, 10>, 16, unsigned> E;
63
64 E e;
65 assert(e() == 6958);
66 }
67
68 void
test2()69 test2()
70 {
71 typedef std::independent_bits_engine<rand1<unsigned, 0, 100>, 16, unsigned> E;
72
73 E e;
74 assert(e() == 66);
75 }
76
77 void
test3()78 test3()
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
86 void
test4()87 test4()
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
95 void
test5()96 test5()
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
104 void
test6()105 test6()
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
113 void
test7()114 test7()
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
122 void
test8()123 test8()
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
main()131 int main()
132 {
133 test1();
134 test2();
135 test3();
136 test4();
137 test5();
138 test6();
139 test7();
140 test8();
141 }
142