146 lines · cpp
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-exception6//7//===----------------------------------------------------------------------===//8 9// UNSUPPORTED: c++03, c++11, c++14, c++1710 11// template <class T>12// constexpr int countr_one(T x) noexcept;13 14// Constraints: T is an unsigned integer type15// Returns: The number of consecutive 1 bits, starting from the least significant bit.16// [ Note: Returns N if x == std::numeric_limits<T>::max(). ]17 18#include <bit>19#include <cassert>20#include <cstddef>21#include <cstdint>22#include <limits>23#include <type_traits>24 25#include "test_macros.h"26 27struct A {};28enum E1 : unsigned char { rEd };29enum class E2 : unsigned char { red };30 31template <class T>32constexpr bool test()33{34 ASSERT_SAME_TYPE(decltype(std::countr_one(T())), int);35 ASSERT_NOEXCEPT(std::countr_one(T()));36 T max = std::numeric_limits<T>::max();37 38 assert(std::countr_one(T(0)) == 0);39 assert(std::countr_one(T(1)) == 1);40 assert(std::countr_one(T(2)) == 0);41 assert(std::countr_one(T(3)) == 2);42 assert(std::countr_one(T(4)) == 0);43 assert(std::countr_one(T(5)) == 1);44 assert(std::countr_one(T(6)) == 0);45 assert(std::countr_one(T(7)) == 3);46 assert(std::countr_one(T(8)) == 0);47 assert(std::countr_one(T(9)) == 1);48 assert(std::countr_one(T(126)) == 0);49 assert(std::countr_one(T(127)) == 7);50 assert(std::countr_one(T(128)) == 0);51 assert(std::countr_one(T(max - 1)) == 0);52 assert(std::countr_one(max) == std::numeric_limits<T>::digits);53 54#ifndef TEST_HAS_NO_INT12855 if constexpr (std::is_same_v<T, __uint128_t>) {56 T val = 128;57 assert(std::countr_one(val-1) == 7);58 assert(std::countr_one(val) == 0);59 assert(std::countr_one(val+1) == 1);60 val <<= 32;61 assert(std::countr_one(val-1) == 39);62 assert(std::countr_one(val) == 0);63 assert(std::countr_one(val+1) == 1);64 val <<= 60;65 assert(std::countr_one(val-1) == 99);66 assert(std::countr_one(val) == 0);67 assert(std::countr_one(val+1) == 1);68 }69#endif70 71 return true;72}73 74int main(int, char**)75{76 {77 auto lambda = [](auto x) -> decltype(std::countr_one(x)) {};78 using L = decltype(lambda);79 80 static_assert(!std::is_invocable_v<L, signed char>);81 static_assert(!std::is_invocable_v<L, short>);82 static_assert(!std::is_invocable_v<L, int>);83 static_assert(!std::is_invocable_v<L, long>);84 static_assert(!std::is_invocable_v<L, long long>);85#ifndef TEST_HAS_NO_INT12886 static_assert(!std::is_invocable_v<L, __int128_t>);87#endif88 89 static_assert(!std::is_invocable_v<L, std::int8_t>);90 static_assert(!std::is_invocable_v<L, std::int16_t>);91 static_assert(!std::is_invocable_v<L, std::int32_t>);92 static_assert(!std::is_invocable_v<L, std::int64_t>);93 static_assert(!std::is_invocable_v<L, std::intmax_t>);94 static_assert(!std::is_invocable_v<L, std::intptr_t>);95 static_assert(!std::is_invocable_v<L, std::ptrdiff_t>);96 97 static_assert(!std::is_invocable_v<L, bool>);98 static_assert(!std::is_invocable_v<L, char>);99 static_assert(!std::is_invocable_v<L, wchar_t>);100#ifndef TEST_HAS_NO_CHAR8_T101 static_assert(!std::is_invocable_v<L, char8_t>);102#endif103 static_assert(!std::is_invocable_v<L, char16_t>);104 static_assert(!std::is_invocable_v<L, char32_t>);105 106 static_assert(!std::is_invocable_v<L, A>);107 static_assert(!std::is_invocable_v<L, A*>);108 static_assert(!std::is_invocable_v<L, E1>);109 static_assert(!std::is_invocable_v<L, E2>);110 }111 112 static_assert(test<unsigned char>());113 static_assert(test<unsigned short>());114 static_assert(test<unsigned int>());115 static_assert(test<unsigned long>());116 static_assert(test<unsigned long long>());117#ifndef TEST_HAS_NO_INT128118 static_assert(test<__uint128_t>());119#endif120 static_assert(test<std::uint8_t>());121 static_assert(test<std::uint16_t>());122 static_assert(test<std::uint32_t>());123 static_assert(test<std::uint64_t>());124 static_assert(test<std::uintmax_t>());125 static_assert(test<std::uintptr_t>());126 static_assert(test<std::size_t>());127 128 test<unsigned char>();129 test<unsigned short>();130 test<unsigned int>();131 test<unsigned long>();132 test<unsigned long long>();133#ifndef TEST_HAS_NO_INT128134 test<__uint128_t>();135#endif136 test<std::uint8_t>();137 test<std::uint16_t>();138 test<std::uint32_t>();139 test<std::uint64_t>();140 test<std::uintmax_t>();141 test<std::uintptr_t>();142 test<std::size_t>();143 144 return 0;145}146