| //===----------------------------------------------------------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is dual licensed under the MIT and the University of Illinois Open |
| // Source Licenses. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // UNSUPPORTED: c++03, c++11, c++14, c++17 |
| |
| // template <class T> |
| // constexpr int countr_zero(T x) noexcept; |
| |
| // Constraints: T is an unsigned integer type |
| // Returns: The number of consecutive 0 bits, starting from the most significant bit. |
| // [ Note: Returns N if x == 0. ] |
| |
| #include <bit> |
| #include <cassert> |
| #include <cstdint> |
| #include <type_traits> |
| |
| #include "test_macros.h" |
| |
| struct A {}; |
| enum E1 : unsigned char { rEd }; |
| enum class E2 : unsigned char { red }; |
| |
| template <class T> |
| constexpr bool test() |
| { |
| ASSERT_SAME_TYPE(decltype(std::countr_zero(T())), int); |
| ASSERT_NOEXCEPT(std::countr_zero(T())); |
| T max = std::numeric_limits<T>::max(); |
| |
| assert(std::countr_zero(T(0)) == std::numeric_limits<T>::digits); |
| assert(std::countr_zero(T(1)) == 0); |
| assert(std::countr_zero(T(2)) == 1); |
| assert(std::countr_zero(T(3)) == 0); |
| assert(std::countr_zero(T(4)) == 2); |
| assert(std::countr_zero(T(5)) == 0); |
| assert(std::countr_zero(T(6)) == 1); |
| assert(std::countr_zero(T(7)) == 0); |
| assert(std::countr_zero(T(8)) == 3); |
| assert(std::countr_zero(T(9)) == 0); |
| assert(std::countr_zero(T(126)) == 1); |
| assert(std::countr_zero(T(127)) == 0); |
| assert(std::countr_zero(T(128)) == 7); |
| assert(std::countr_zero(T(129)) == 0); |
| assert(std::countr_zero(T(130)) == 1); |
| assert(std::countr_zero(max) == 0); |
| |
| #ifndef _LIBCPP_HAS_NO_INT128 |
| if constexpr (std::is_same_v<T, __uint128_t>) { |
| T val = T(128) << 32; |
| assert(std::countr_zero(val-1) == 0); |
| assert(std::countr_zero(val) == 39); |
| assert(std::countr_zero(val+1) == 0); |
| val <<= 60; |
| assert(std::countr_zero(val-1) == 0); |
| assert(std::countr_zero(val) == 99); |
| assert(std::countr_zero(val+1) == 0); |
| } |
| #endif |
| |
| return true; |
| } |
| |
| int main(int, char**) |
| { |
| { |
| auto lambda = [](auto x) -> decltype(std::countr_zero(x)) {}; |
| using L = decltype(lambda); |
| |
| static_assert(!std::is_invocable_v<L, signed char>); |
| static_assert(!std::is_invocable_v<L, short>); |
| static_assert(!std::is_invocable_v<L, int>); |
| static_assert(!std::is_invocable_v<L, long>); |
| static_assert(!std::is_invocable_v<L, long long>); |
| #ifndef _LIBCPP_HAS_NO_INT128 |
| static_assert(!std::is_invocable_v<L, __int128_t>); |
| #endif |
| |
| static_assert(!std::is_invocable_v<L, int8_t>); |
| static_assert(!std::is_invocable_v<L, int16_t>); |
| static_assert(!std::is_invocable_v<L, int32_t>); |
| static_assert(!std::is_invocable_v<L, int64_t>); |
| static_assert(!std::is_invocable_v<L, intmax_t>); |
| static_assert(!std::is_invocable_v<L, intptr_t>); |
| static_assert(!std::is_invocable_v<L, ptrdiff_t>); |
| |
| static_assert(!std::is_invocable_v<L, bool>); |
| static_assert(!std::is_invocable_v<L, char>); |
| static_assert(!std::is_invocable_v<L, wchar_t>); |
| #ifndef _LIBCPP_HAS_NO_CHAR8_T |
| static_assert(!std::is_invocable_v<L, char8_t>); |
| #endif |
| static_assert(!std::is_invocable_v<L, char16_t>); |
| static_assert(!std::is_invocable_v<L, char32_t>); |
| |
| static_assert(!std::is_invocable_v<L, A>); |
| static_assert(!std::is_invocable_v<L, A*>); |
| static_assert(!std::is_invocable_v<L, E1>); |
| static_assert(!std::is_invocable_v<L, E2>); |
| } |
| |
| static_assert(test<unsigned char>()); |
| static_assert(test<unsigned short>()); |
| static_assert(test<unsigned int>()); |
| static_assert(test<unsigned long>()); |
| static_assert(test<unsigned long long>()); |
| #ifndef _LIBCPP_HAS_NO_INT128 |
| static_assert(test<__uint128_t>()); |
| #endif |
| static_assert(test<uint8_t>()); |
| static_assert(test<uint16_t>()); |
| static_assert(test<uint32_t>()); |
| static_assert(test<uint64_t>()); |
| static_assert(test<uintmax_t>()); |
| static_assert(test<uintptr_t>()); |
| static_assert(test<size_t>()); |
| |
| test<unsigned char>(); |
| test<unsigned short>(); |
| test<unsigned int>(); |
| test<unsigned long>(); |
| test<unsigned long long>(); |
| #ifndef _LIBCPP_HAS_NO_INT128 |
| test<__uint128_t>(); |
| #endif |
| test<uint8_t>(); |
| test<uint16_t>(); |
| test<uint32_t>(); |
| test<uint64_t>(); |
| test<uintmax_t>(); |
| test<uintptr_t>(); |
| test<size_t>(); |
| |
| return 0; |
| } |