xref: /llvm-project/libcxx/test/std/numerics/rand/rand.dist/rand.dist.uni/rand.dist.uni.int/int128.pass.cpp (revision 0a4aa8a122aa097499c498b639a75b5e9a73e9f0)
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 // UNSUPPORTED: c++03
10 
11 // <random>
12 
13 // template<class _IntType = int>
14 // class uniform_int_distribution
15 
16 // template<class _URNG> result_type operator()(_URNG& g);
17 
18 
19 #include <cassert>
20 #include <cstdint>
21 #include <limits>
22 #include <random>
23 
24 #include "test_macros.h"
25 
main(int,char **)26 int main(int, char**) {
27 
28 #ifndef TEST_HAS_NO_INT128
29 
30   // Test that values outside of the 64-bit range can be produced.
31   {
32     std::minstd_rand0 e;
33     std::uniform_int_distribution<__int128_t> d;
34     assert(d.min() == 0 && d.max() == std::numeric_limits<__int128_t>::max());
35     bool all_in_64bit_range = true;
36     for (int i = 0; i < 100; ++i) {
37       __int128_t n = d(e);
38       all_in_64bit_range = all_in_64bit_range && (n <= UINT64_MAX);
39     }
40     assert(!all_in_64bit_range);
41   }
42 
43   // Same test as above with min/max set and outside the 64-bit range.
44   {
45     __int128_t a = ((__int128_t)INT64_MIN) * 10;
46     __int128_t b = ((__int128_t)INT64_MAX) * 10;
47     std::minstd_rand0 e;
48     std::uniform_int_distribution<__int128_t> d(a, b);
49     assert(d.min() == a && d.max() == b);
50     bool all_in_64bit_range = true;
51     for (int i = 0; i < 100; ++i) {
52       __int128_t n = d(e);
53       assert(a <= n && n <= b);
54       all_in_64bit_range = all_in_64bit_range && (INT64_MIN <= n) && (n <= (INT64_MAX));
55     }
56     assert(!all_in_64bit_range);
57   }
58 
59   // Same test as above with __uint128_t.
60   {
61     __uint128_t a = UINT64_MAX / 3;
62     __uint128_t b = ((__uint128_t)UINT64_MAX) * 10;
63     std::minstd_rand0 e;
64     std::uniform_int_distribution<__uint128_t> d(a, b);
65     assert(d.min() == a && d.max() == b);
66     bool all_in_64bit_range = true;
67     for (int i = 0; i < 100; ++i) {
68       __uint128_t n = d(e);
69       assert(a <= n && n <= b);
70       all_in_64bit_range = all_in_64bit_range && (n <= (UINT64_MAX));
71     }
72     assert(!all_in_64bit_range);
73   }
74 
75   // Regression test for PR#51520:
76   {
77     std::minstd_rand0 e;
78     std::uniform_int_distribution<__int128_t> d(INT64_MIN, INT64_MAX);
79     assert(d.min() == INT64_MIN && d.max() == INT64_MAX);
80     for (int i = 0; i < 100; ++i) {
81       __int128_t n = d(e);
82       assert((INT64_MIN <= n) && (n <= INT64_MAX));
83     }
84   }
85 
86 #endif // TEST_HAS_NO_INT128
87 
88   return 0;
89 }
90