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 // test unsigned long to_ulong() const;
10 
11 #include <bitset>
12 #include <algorithm>
13 #include <type_traits>
14 #include <limits>
15 #include <climits>
16 #include <cassert>
17 
18 #include "test_macros.h"
19 
20 template <std::size_t N>
test_to_ulong()21 void test_to_ulong() {
22     const std::size_t M = sizeof(unsigned long) * CHAR_BIT < N ? sizeof(unsigned long) * CHAR_BIT : N;
23     const bool is_M_zero = std::integral_constant<bool, M == 0>::value; // avoid compiler warnings
24     const std::size_t X = is_M_zero ? sizeof(unsigned long) * CHAR_BIT - 1 : sizeof(unsigned long) * CHAR_BIT - M;
25     const std::size_t max = is_M_zero ? 0 : std::size_t(std::numeric_limits<unsigned long>::max()) >> X;
26     std::size_t tests[] = {
27         0,
28         std::min<std::size_t>(1, max),
29         std::min<std::size_t>(2, max),
30         std::min<std::size_t>(3, max),
31         std::min(max, max-3),
32         std::min(max, max-2),
33         std::min(max, max-1),
34         max
35     };
36     for (std::size_t i = 0; i < sizeof(tests)/sizeof(tests[0]); ++i) {
37         std::size_t j = tests[i];
38         std::bitset<N> v(j);
39         assert(j == v.to_ulong());
40     }
41 
42     { // test values bigger than can fit into the bitset
43         const unsigned long val = 0x5AFFFFA5UL;
44         const bool canFit = N < sizeof(unsigned long) * CHAR_BIT;
45         const unsigned long mask = canFit ? (1UL << (canFit ? N : 0)) - 1 : (unsigned long)(-1); // avoid compiler warnings
46         std::bitset<N> v(val);
47         assert(v.to_ulong() == (val & mask)); // we shouldn't return bit patterns from outside the limits of the bitset.
48     }
49 }
50 
main(int,char **)51 int main(int, char**) {
52     test_to_ulong<0>();
53     test_to_ulong<1>();
54     test_to_ulong<31>();
55     test_to_ulong<32>();
56     test_to_ulong<33>();
57     test_to_ulong<63>();
58     test_to_ulong<64>();
59     test_to_ulong<65>();
60     test_to_ulong<1000>();
61 
62     return 0;
63 }
64