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 UIntType, UIntType a, UIntType c, UIntType m>
12// class linear_congruential_engine;
13
14// linear_congruential_engine(const linear_congruential_engine&);
15
16#include <random>
17#include <cassert>
18
19#include "test_macros.h"
20
21template <class T, T a, T c, T m>
22void
23test1()
24{
25 typedef std::linear_congruential_engine<T, a, c, m> E;
26 E e1;
27 E e2 = e1;
28 assert(e1 == e2);
29 (void)e1();
30 (void)e2();
31 assert(e1 == e2);
32}
33
34template <class T>
35void
36test()
37{
38 const int W = sizeof(T) * CHAR_BIT;
39 const T M(static_cast<T>(-1));
40 const T A(static_cast<T>((static_cast<T>(1) << (W / 2)) - 1));
41
42 // Cases where m = 0
43 test1<T, 0, 0, 0>();
44 test1<T, A, 0, 0>();
45 test1<T, 0, 1, 0>();
46 test1<T, A, 1, 0>();
47
48 // Cases where m = 2^n for n < w
49 test1<T, 0, 0, 256>();
50 test1<T, 5, 0, 256>();
51 test1<T, 0, 1, 256>();
52 test1<T, 5, 1, 256>();
53
54 // Cases where m is odd and a = 0
55 test1<T, 0, 0, M>();
56 test1<T, 0, M - 2, M>();
57 test1<T, 0, M - 1, M>();
58
59 // Cases where m is odd and m % a <= m / a (Schrage)
60 test1<T, A, 0, M>();
61 test1<T, A, M - 2, M>();
62 test1<T, A, M - 1, M>();
63}
64
65template <class T>
66void test_ext() {
67 const T M(static_cast<T>(-1));
68
69 // Cases where m is odd and m % a > m / a
70 test1<T, M - 2, 0, M>();
71 test1<T, M - 2, M - 2, M>();
72 test1<T, M - 2, M - 1, M>();
73 test1<T, M - 1, 0, M>();
74 test1<T, M - 1, M - 2, M>();
75 test1<T, M - 1, M - 1, M>();
76}
77
78int main(int, char**)
79{
80 test<unsigned short>();
81 test_ext<unsigned short>();
82 test<unsigned int>();
83 test_ext<unsigned int>();
84 test<unsigned long>();
85 test_ext<unsigned long>();
86 test<unsigned long long>();
87 // This isn't implemented on platforms without __int128
88#ifndef _LIBCPP_HAS_NO_INT128
89 test_ext<unsigned long long>();
90#endif
91
92 return 0;
93}
94

source code of libcxx/test/std/numerics/rand/rand.eng/rand.eng.lcong/copy.pass.cpp