142 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 countl_one(T x) noexcept;13 14// Constraints: T is an unsigned integer type15// The number of consecutive 1 bits, starting from the most 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::countl_one(T())), int);35 ASSERT_NOEXCEPT(std::countl_one(T()));36 T max = std::numeric_limits<T>::max();37 38 assert(std::countl_one(T(0)) == 0);39 assert(std::countl_one(T(1)) == 0);40 assert(std::countl_one(T(10)) == 0);41 assert(std::countl_one(T(100)) == 0);42 assert(std::countl_one(max) == std::numeric_limits<T>::digits);43 assert(std::countl_one(T(max - 1)) == std::numeric_limits<T>::digits - 1);44 assert(std::countl_one(T(max - 2)) == std::numeric_limits<T>::digits - 2);45 assert(std::countl_one(T(max - 3)) == std::numeric_limits<T>::digits - 2);46 assert(std::countl_one(T(max - 4)) == std::numeric_limits<T>::digits - 3);47 assert(std::countl_one(T(max - 5)) == std::numeric_limits<T>::digits - 3);48 assert(std::countl_one(T(max - 6)) == std::numeric_limits<T>::digits - 3);49 assert(std::countl_one(T(max - 7)) == std::numeric_limits<T>::digits - 3);50 assert(std::countl_one(T(max - 8)) == std::numeric_limits<T>::digits - 4);51 assert(std::countl_one(T(max - 9)) == std::numeric_limits<T>::digits - 4);52 assert(std::countl_one(T(max - 126)) == std::numeric_limits<T>::digits - 7);53 assert(std::countl_one(T(max - 127)) == std::numeric_limits<T>::digits - 7);54 assert(std::countl_one(T(max - 128)) == std::numeric_limits<T>::digits - 8);55 56#ifndef TEST_HAS_NO_INT12857 if constexpr (std::is_same_v<T, __uint128_t>) {58 T val = 128;59 assert(std::countl_one(~val) == 120);60 val <<= 32;61 assert(std::countl_one(~val) == 88);62 val <<= 60;63 assert(std::countl_one(~val) == 28);64 }65#endif66 67 return true;68}69 70int main(int, char**)71{72 {73 auto lambda = [](auto x) -> decltype(std::countl_one(x)) {};74 using L = decltype(lambda);75 76 static_assert(!std::is_invocable_v<L, signed char>);77 static_assert(!std::is_invocable_v<L, short>);78 static_assert(!std::is_invocable_v<L, int>);79 static_assert(!std::is_invocable_v<L, long>);80 static_assert(!std::is_invocable_v<L, long long>);81#ifndef TEST_HAS_NO_INT12882 static_assert(!std::is_invocable_v<L, __int128_t>);83#endif84 85 static_assert(!std::is_invocable_v<L, std::int8_t>);86 static_assert(!std::is_invocable_v<L, std::int16_t>);87 static_assert(!std::is_invocable_v<L, std::int32_t>);88 static_assert(!std::is_invocable_v<L, std::int64_t>);89 static_assert(!std::is_invocable_v<L, std::intmax_t>);90 static_assert(!std::is_invocable_v<L, std::intptr_t>);91 static_assert(!std::is_invocable_v<L, std::ptrdiff_t>);92 93 static_assert(!std::is_invocable_v<L, bool>);94 static_assert(!std::is_invocable_v<L, char>);95 static_assert(!std::is_invocable_v<L, wchar_t>);96#ifndef TEST_HAS_NO_CHAR8_T97 static_assert(!std::is_invocable_v<L, char8_t>);98#endif99 static_assert(!std::is_invocable_v<L, char16_t>);100 static_assert(!std::is_invocable_v<L, char32_t>);101 102 static_assert(!std::is_invocable_v<L, A>);103 static_assert(!std::is_invocable_v<L, A*>);104 static_assert(!std::is_invocable_v<L, E1>);105 static_assert(!std::is_invocable_v<L, E2>);106 }107 108 static_assert(test<unsigned char>());109 static_assert(test<unsigned short>());110 static_assert(test<unsigned int>());111 static_assert(test<unsigned long>());112 static_assert(test<unsigned long long>());113#ifndef TEST_HAS_NO_INT128114 static_assert(test<__uint128_t>());115#endif116 static_assert(test<std::uint8_t>());117 static_assert(test<std::uint16_t>());118 static_assert(test<std::uint32_t>());119 static_assert(test<std::uint64_t>());120 static_assert(test<std::uintmax_t>());121 static_assert(test<std::uintptr_t>());122 static_assert(test<std::size_t>());123 124 test<unsigned char>();125 test<unsigned short>();126 test<unsigned int>();127 test<unsigned long>();128 test<unsigned long long>();129#ifndef TEST_HAS_NO_INT128130 test<__uint128_t>();131#endif132 test<std::uint8_t>();133 test<std::uint16_t>();134 test<std::uint32_t>();135 test<std::uint64_t>();136 test<std::uintmax_t>();137 test<std::uintptr_t>();138 test<std::size_t>();139 140 return 0;141}142