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, c++11, c++14, c++17
10
11// template <class T>
12// constexpr bool has_single_bit(T x) noexcept;
13
14// Constraints: T is an unsigned integer type
15
16#include <bit>
17#include <cassert>
18#include <cstddef>
19#include <cstdint>
20#include <limits>
21#include <type_traits>
22
23#include "test_macros.h"
24
25struct A {};
26enum E1 : unsigned char { rEd };
27enum class E2 : unsigned char { red };
28
29template <class T>
30constexpr bool test()
31{
32 ASSERT_SAME_TYPE(decltype(std::has_single_bit(T())), bool);
33 ASSERT_NOEXCEPT(std::has_single_bit(T()));
34 T max = std::numeric_limits<T>::max();
35
36 assert(!std::has_single_bit(T(0)));
37 assert( std::has_single_bit(T(1)));
38 assert( std::has_single_bit(T(2)));
39 assert(!std::has_single_bit(T(3)));
40 assert( std::has_single_bit(T(4)));
41 assert(!std::has_single_bit(T(5)));
42 assert(!std::has_single_bit(T(6)));
43 assert(!std::has_single_bit(T(7)));
44 assert( std::has_single_bit(T(8)));
45 assert(!std::has_single_bit(T(9)));
46 assert(!std::has_single_bit(T(127)));
47 assert( std::has_single_bit(T(128)));
48 assert(!std::has_single_bit(T(129)));
49 assert(!std::has_single_bit(max));
50
51#ifndef TEST_HAS_NO_INT128
52 if constexpr (std::is_same_v<T, __uint128_t>) {
53 T val = T(1) << 32;
54 assert(!std::has_single_bit(val-1));
55 assert( std::has_single_bit(val));
56 assert(!std::has_single_bit(val+1));
57 val <<= 60;
58 assert(!std::has_single_bit(val-1));
59 assert( std::has_single_bit(val));
60 assert(!std::has_single_bit(val+1));
61
62 T x = (T(1) << 63);
63 T y = (T(1) << 64);
64 assert( std::has_single_bit(x));
65 assert( std::has_single_bit(y));
66 assert(!std::has_single_bit(x + y));
67 }
68#endif
69
70 return true;
71}
72
73int main(int, char**)
74{
75 {
76 auto lambda = [](auto x) -> decltype(std::has_single_bit(x)) {};
77 using L = decltype(lambda);
78
79 static_assert(!std::is_invocable_v<L, signed char>);
80 static_assert(!std::is_invocable_v<L, short>);
81 static_assert(!std::is_invocable_v<L, int>);
82 static_assert(!std::is_invocable_v<L, long>);
83 static_assert(!std::is_invocable_v<L, long long>);
84#ifndef TEST_HAS_NO_INT128
85 static_assert(!std::is_invocable_v<L, __int128_t>);
86#endif
87
88 static_assert(!std::is_invocable_v<L, std::int8_t>);
89 static_assert(!std::is_invocable_v<L, std::int16_t>);
90 static_assert(!std::is_invocable_v<L, std::int32_t>);
91 static_assert(!std::is_invocable_v<L, std::int64_t>);
92 static_assert(!std::is_invocable_v<L, std::intmax_t>);
93 static_assert(!std::is_invocable_v<L, std::intptr_t>);
94 static_assert(!std::is_invocable_v<L, std::ptrdiff_t>);
95
96 static_assert(!std::is_invocable_v<L, bool>);
97 static_assert(!std::is_invocable_v<L, char>);
98 static_assert(!std::is_invocable_v<L, wchar_t>);
99#ifndef TEST_HAS_NO_CHAR8_T
100 static_assert(!std::is_invocable_v<L, char8_t>);
101#endif
102 static_assert(!std::is_invocable_v<L, char16_t>);
103 static_assert(!std::is_invocable_v<L, char32_t>);
104
105 static_assert(!std::is_invocable_v<L, A>);
106 static_assert(!std::is_invocable_v<L, A*>);
107 static_assert(!std::is_invocable_v<L, E1>);
108 static_assert(!std::is_invocable_v<L, E2>);
109 }
110
111 static_assert(test<unsigned char>());
112 static_assert(test<unsigned short>());
113 static_assert(test<unsigned int>());
114 static_assert(test<unsigned long>());
115 static_assert(test<unsigned long long>());
116#ifndef TEST_HAS_NO_INT128
117 static_assert(test<__uint128_t>());
118#endif
119 static_assert(test<std::uint8_t>());
120 static_assert(test<std::uint16_t>());
121 static_assert(test<std::uint32_t>());
122 static_assert(test<std::uint64_t>());
123 static_assert(test<std::uintmax_t>());
124 static_assert(test<std::uintptr_t>());
125 static_assert(test<std::size_t>());
126
127 test<unsigned char>();
128 test<unsigned short>();
129 test<unsigned int>();
130 test<unsigned long>();
131 test<unsigned long long>();
132#ifndef TEST_HAS_NO_INT128
133 test<__uint128_t>();
134#endif
135 test<std::uint8_t>();
136 test<std::uint16_t>();
137 test<std::uint32_t>();
138 test<std::uint64_t>();
139 test<std::uintmax_t>();
140 test<std::uintptr_t>();
141 test<std::size_t>();
142
143 return 0;
144}
145

source code of libcxx/test/std/numerics/bit/bit.pow.two/has_single_bit.pass.cpp