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 k>
12 // class shuffle_order_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::knuth_b E;
64
65 E e;
66 assert(e() == 152607844u);
67 }
68
69 void
test2()70 test2()
71 {
72 typedef rand1<unsigned long long, 0, 0xFFFFFFFFFFFFFFFFull> E0;
73 typedef std::shuffle_order_engine<E0, 101> E;
74 E e;
75 e.discard(400);
76 assert(e() == 501);
77 }
78
79 void
test3()80 test3()
81 {
82 typedef rand1<unsigned long long, 0, 0xFFFFFFFFFFFFFFFFull> E0;
83 typedef std::shuffle_order_engine<E0, 100> E;
84 E e;
85 e.discard(400);
86 assert(e() == 500);
87 }
88
main(int,char **)89 int main(int, char**)
90 {
91 test1();
92 test2();
93 test3();
94
95 return 0;
96 }
97