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 // public:
15 //     engine characteristics
16 //     static constexpr result_type multiplier = a;
17 //     static constexpr result_type increment = c;
18 //     static constexpr result_type modulus = m;
19 //     static constexpr result_type min() { return c == 0u ? 1u: 0u;}
20 //     static constexpr result_type max() { return m - 1u;}
21 //     static constexpr result_type default_seed = 1u;
22 
23 #include <random>
24 #include <type_traits>
25 #include <cassert>
26 
27 #include "test_macros.h"
28 
29 template <class T>
30 void where(const T &) {}
31 
32 template <class T, T a, T c, T m>
33 void
34 test1()
35 {
36     typedef std::linear_congruential_engine<T, a, c, m> LCE;
37     typedef typename LCE::result_type result_type;
38     static_assert((LCE::multiplier == a), "");
39     static_assert((LCE::increment == c), "");
40     static_assert((LCE::modulus == m), "");
41 #if TEST_STD_VER >= 11
42     static_assert((LCE::min() == (c == 0u ? 1u: 0u)), "");
43 #else
44     assert((LCE::min() == (c == 0u ? 1u: 0u)));
45 #endif
46 
47     TEST_DIAGNOSTIC_PUSH
48     TEST_MSVC_DIAGNOSTIC_IGNORED(4310) // cast truncates constant value
49 
50 #if TEST_STD_VER >= 11
51     static_assert((LCE::max() == result_type(m - 1u)), "");
52 #else
53     assert((LCE::max() == result_type(m - 1u)));
54 #endif
55 
56     TEST_DIAGNOSTIC_POP
57 
58     static_assert((LCE::default_seed == 1), "");
59     where(LCE::multiplier);
60     where(LCE::increment);
61     where(LCE::modulus);
62     where(LCE::default_seed);
63 }
64 
65 template <class T>
66 void
67 test()
68 {
69     test1<T, 0, 0, 0>();
70     test1<T, 0, 1, 2>();
71     test1<T, 1, 1, 2>();
72     const T M(static_cast<T>(-1));
73     test1<T, 0, 0, M>();
74     test1<T, 0, M-2, M>();
75     test1<T, 0, M-1, M>();
76     test1<T, M-2, 0, M>();
77     test1<T, M-2, M-2, M>();
78     test1<T, M-2, M-1, M>();
79     test1<T, M-1, 0, M>();
80     test1<T, M-1, M-2, M>();
81     test1<T, M-1, M-1, M>();
82 }
83 
84 int main(int, char**)
85 {
86     test<unsigned short>();
87     test<unsigned int>();
88     test<unsigned long>();
89     test<unsigned long long>();
90 
91   return 0;
92 }
93