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 // unsigned long long to_ullong() const; // constexpr since C++23
10
11 #include <bitset>
12 #include <algorithm>
13 #include <type_traits>
14 #include <climits>
15 #include <cassert>
16
17 #include "test_macros.h"
18
19 template <std::size_t N>
test_to_ullong()20 TEST_CONSTEXPR_CXX23 void test_to_ullong() {
21 const std::size_t M = sizeof(unsigned long long) * CHAR_BIT < N ? sizeof(unsigned long long) * CHAR_BIT : N;
22 const bool is_M_zero = std::integral_constant<bool, M == 0>::value; // avoid compiler warnings
23 const std::size_t X = is_M_zero ? sizeof(unsigned long long) * CHAR_BIT - 1 : sizeof(unsigned long long) * CHAR_BIT - M;
24 const unsigned long long max = is_M_zero ? 0 : (unsigned long long)(-1) >> X;
25 unsigned long long tests[] = {
26 0,
27 std::min<unsigned long long>(1, max),
28 std::min<unsigned long long>(2, max),
29 std::min<unsigned long long>(3, max),
30 std::min(max, max-3),
31 std::min(max, max-2),
32 std::min(max, max-1),
33 max
34 };
35 for (unsigned long long j : tests) {
36 std::bitset<N> v(j);
37 assert(j == v.to_ullong());
38 }
39 { // test values bigger than can fit into the bitset
40 const unsigned long long val = 0x55AAAAFFFFAAAA55ULL;
41 const bool canFit = N < sizeof(unsigned long long) * CHAR_BIT;
42 const unsigned long long mask = canFit ? (1ULL << (canFit ? N : 0)) - 1 : (unsigned long long)(-1); // avoid compiler warnings
43 std::bitset<N> v(val);
44 assert(v.to_ullong() == (val & mask)); // we shouldn't return bit patterns from outside the limits of the bitset.
45 }
46 }
47
test()48 TEST_CONSTEXPR_CXX23 bool test() {
49 test_to_ullong<0>();
50 test_to_ullong<1>();
51 test_to_ullong<31>();
52 test_to_ullong<32>();
53 test_to_ullong<33>();
54 test_to_ullong<63>();
55 test_to_ullong<64>();
56 test_to_ullong<65>();
57 test_to_ullong<1000>();
58
59 return true;
60 }
61
main(int,char **)62 int main(int, char**) {
63 test();
64 #if TEST_STD_VER > 20
65 static_assert(test());
66 #endif
67
68 return 0;
69 }
70