1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8
9 // <random>
10
11 // template<class Engine, size_t w, class UIntType>
12 // class independent_bits_engine
13
14 // result_type operator()();
15
16 #include <random>
17 #include <cassert>
18
19 #include "test_macros.h"
20
21 template <class UIntType, UIntType Min, UIntType Max>
22 class rand1
23 {
24 public:
25 // types
26 typedef UIntType result_type;
27
28 private:
29 result_type x_;
30
31 static_assert(Min < Max, "rand1 invalid parameters");
32 public:
33
34 #if TEST_STD_VER < 11 && defined(_LIBCPP_VERSION)
35 // Workaround for lack of constexpr in C++03
36 static const result_type _Min = Min;
37 static const result_type _Max = Max;
38 #endif
39
min()40 static TEST_CONSTEXPR result_type min() {return Min;}
max()41 static TEST_CONSTEXPR result_type max() {return Max;}
42
rand1(result_type sd=Min)43 explicit rand1(result_type sd = Min) : x_(sd)
44 {
45 if (x_ > Max)
46 x_ = Max;
47 }
48
operator ()()49 result_type operator()()
50 {
51 result_type r = x_;
52 if (x_ < Max)
53 ++x_;
54 else
55 x_ = Min;
56 return r;
57 }
58 };
59
60 void
test1()61 test1()
62 {
63 typedef std::independent_bits_engine<rand1<unsigned, 0, 10>, 16, unsigned> E;
64
65 E e;
66 assert(e() == 6958);
67 }
68
69 void
test2()70 test2()
71 {
72 typedef std::independent_bits_engine<rand1<unsigned, 0, 100>, 16, unsigned> E;
73
74 E e;
75 assert(e() == 66);
76 }
77
78 void
test3()79 test3()
80 {
81 typedef std::independent_bits_engine<rand1<unsigned, 0, 0xFFFFFFFF>, 32, unsigned> E;
82
83 E e(5);
84 assert(e() == 5);
85 }
86
87 void
test4()88 test4()
89 {
90 typedef std::independent_bits_engine<rand1<unsigned, 0, 0xFFFFFFFF>, 7, unsigned> E;
91
92 E e(129);
93 assert(e() == 1);
94 }
95
96 void
test5()97 test5()
98 {
99 typedef std::independent_bits_engine<rand1<unsigned, 2, 3>, 1, unsigned> E;
100
101 E e(6);
102 assert(e() == 1);
103 }
104
105 void
test6()106 test6()
107 {
108 typedef std::independent_bits_engine<rand1<unsigned, 2, 3>, 11, unsigned> E;
109
110 E e(6);
111 assert(e() == 1365);
112 }
113
114 void
test7()115 test7()
116 {
117 typedef std::independent_bits_engine<rand1<unsigned, 2, 3>, 32, unsigned> E;
118
119 E e(6);
120 assert(e() == 2863311530u);
121 }
122
123 void
test8()124 test8()
125 {
126 typedef std::independent_bits_engine<std::mt19937, 64, unsigned long long> E;
127
128 E e(6);
129 assert(e() == 16470362623952407241ull);
130 }
131
main(int,char **)132 int main(int, char**)
133 {
134 test1();
135 test2();
136 test3();
137 test4();
138 test5();
139 test6();
140 test7();
141 test8();
142
143 return 0;
144 }
145