1 //===----------------------------------------------------------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is dual licensed under the MIT and the University of Illinois Open 6 // Source Licenses. See LICENSE.TXT for details. 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 // Remarks: This function shall not participate in overload resolution unless 15 // T is an unsigned integer type 16 17 #include <bit> 18 #include <cstdint> 19 #include <type_traits> 20 #include <cassert> 21 22 #include "test_macros.h" 23 24 class A{}; 25 enum E1 : unsigned char { rEd }; 26 enum class E2 : unsigned char { red }; 27 28 template <typename T> 29 constexpr bool constexpr_test() 30 { 31 return std::has_single_bit(T(1)) 32 && std::has_single_bit(T(2)) 33 && !std::has_single_bit(T(3)) 34 && std::has_single_bit(T(4)) 35 && !std::has_single_bit(T(5)) 36 && !std::has_single_bit(T(6)) 37 && !std::has_single_bit(T(7)) 38 && std::has_single_bit(T(8)) 39 && !std::has_single_bit(T(9)) 40 ; 41 } 42 43 44 template <typename T> 45 void runtime_test() 46 { 47 ASSERT_SAME_TYPE(bool, decltype(std::has_single_bit(T(0)))); 48 ASSERT_NOEXCEPT( std::has_single_bit(T(0))); 49 50 assert(!std::has_single_bit(T(121))); 51 assert(!std::has_single_bit(T(122))); 52 assert(!std::has_single_bit(T(123))); 53 assert(!std::has_single_bit(T(124))); 54 assert(!std::has_single_bit(T(125))); 55 assert(!std::has_single_bit(T(126))); 56 assert(!std::has_single_bit(T(127))); 57 assert( std::has_single_bit(T(128))); 58 assert(!std::has_single_bit(T(129))); 59 assert(!std::has_single_bit(T(130))); 60 } 61 62 int main(int, char**) 63 { 64 65 { 66 auto lambda = [](auto x) -> decltype(std::has_single_bit(x)) {}; 67 using L = decltype(lambda); 68 69 static_assert( std::is_invocable_v<L, unsigned char>, ""); 70 static_assert( std::is_invocable_v<L, unsigned int>, ""); 71 static_assert( std::is_invocable_v<L, unsigned long>, ""); 72 static_assert( std::is_invocable_v<L, unsigned long long>, ""); 73 74 static_assert( std::is_invocable_v<L, uint8_t>, ""); 75 static_assert( std::is_invocable_v<L, uint16_t>, ""); 76 static_assert( std::is_invocable_v<L, uint32_t>, ""); 77 static_assert( std::is_invocable_v<L, uint64_t>, ""); 78 static_assert( std::is_invocable_v<L, size_t>, ""); 79 80 static_assert( std::is_invocable_v<L, uintmax_t>, ""); 81 static_assert( std::is_invocable_v<L, uintptr_t>, ""); 82 83 84 static_assert(!std::is_invocable_v<L, int>, ""); 85 static_assert(!std::is_invocable_v<L, signed int>, ""); 86 static_assert(!std::is_invocable_v<L, long>, ""); 87 static_assert(!std::is_invocable_v<L, long long>, ""); 88 89 static_assert(!std::is_invocable_v<L, int8_t>, ""); 90 static_assert(!std::is_invocable_v<L, int16_t>, ""); 91 static_assert(!std::is_invocable_v<L, int32_t>, ""); 92 static_assert(!std::is_invocable_v<L, int64_t>, ""); 93 static_assert(!std::is_invocable_v<L, ptrdiff_t>, ""); 94 95 static_assert(!std::is_invocable_v<L, bool>, ""); 96 static_assert(!std::is_invocable_v<L, signed char>, ""); 97 static_assert(!std::is_invocable_v<L, char16_t>, ""); 98 static_assert(!std::is_invocable_v<L, char32_t>, ""); 99 100 #ifndef _LIBCPP_HAS_NO_INT128 101 static_assert( std::is_invocable_v<L, __uint128_t>, ""); 102 static_assert(!std::is_invocable_v<L, __int128_t>, ""); 103 #endif 104 105 static_assert(!std::is_invocable_v<L, A>, ""); 106 static_assert(!std::is_invocable_v<L, E1>, ""); 107 static_assert(!std::is_invocable_v<L, E2>, ""); 108 } 109 110 static_assert(constexpr_test<unsigned char>(), ""); 111 static_assert(constexpr_test<unsigned short>(), ""); 112 static_assert(constexpr_test<unsigned>(), ""); 113 static_assert(constexpr_test<unsigned long>(), ""); 114 static_assert(constexpr_test<unsigned long long>(), ""); 115 116 static_assert(constexpr_test<uint8_t>(), ""); 117 static_assert(constexpr_test<uint16_t>(), ""); 118 static_assert(constexpr_test<uint32_t>(), ""); 119 static_assert(constexpr_test<uint64_t>(), ""); 120 static_assert(constexpr_test<size_t>(), ""); 121 static_assert(constexpr_test<uintmax_t>(), ""); 122 static_assert(constexpr_test<uintptr_t>(), ""); 123 124 #ifndef _LIBCPP_HAS_NO_INT128 125 static_assert(constexpr_test<__uint128_t>(), ""); 126 #endif 127 128 runtime_test<unsigned char>(); 129 runtime_test<unsigned>(); 130 runtime_test<unsigned short>(); 131 runtime_test<unsigned long>(); 132 runtime_test<unsigned long long>(); 133 134 runtime_test<uint8_t>(); 135 runtime_test<uint16_t>(); 136 runtime_test<uint32_t>(); 137 runtime_test<uint64_t>(); 138 runtime_test<size_t>(); 139 runtime_test<uintmax_t>(); 140 runtime_test<uintptr_t>(); 141 142 #ifndef _LIBCPP_HAS_NO_INT128 143 runtime_test<__uint128_t>(); 144 145 { 146 __uint128_t val = 128; 147 val <<= 32; 148 assert(!std::has_single_bit(val-1)); 149 assert( std::has_single_bit(val)); 150 assert(!std::has_single_bit(val+1)); 151 val <<= 2; 152 assert(!std::has_single_bit(val-1)); 153 assert( std::has_single_bit(val)); 154 assert(!std::has_single_bit(val+1)); 155 val <<= 3; 156 assert(!std::has_single_bit(val-1)); 157 assert( std::has_single_bit(val)); 158 assert(!std::has_single_bit(val+1)); 159 } 160 #endif 161 162 return 0; 163 } 164