--- /dev/null
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
+// UNSUPPORTED: libcpp-no-concepts
+
+// template<class T>
+// concept integral = // see below
+
+// template<class T>
+// concept signed_integral = // see below
+
+// template<class T>
+// concept unsigned_integral = // see below
+
+// template<class T>
+// concept floating_point = // see below
+
+#include <concepts>
+#include <type_traits>
+
+namespace {
+template <typename T>
+constexpr bool CheckIntegralQualifiers() {
+ constexpr bool result = std::integral<T>;
+ static_assert(std::integral<const T> == result);
+ static_assert(std::integral<volatile T> == result);
+ static_assert(std::integral<const volatile T> == result);
+
+ static_assert(!std::integral<T&>);
+ static_assert(!std::integral<const T&>);
+ static_assert(!std::integral<volatile T&>);
+ static_assert(!std::integral<const volatile T&>);
+
+ static_assert(!std::integral<T&&>);
+ static_assert(!std::integral<const T&&>);
+ static_assert(!std::integral<volatile T&&>);
+ static_assert(!std::integral<const volatile T&&>);
+
+ static_assert(!std::integral<T*>);
+ static_assert(!std::integral<const T*>);
+ static_assert(!std::integral<volatile T*>);
+ static_assert(!std::integral<const volatile T*>);
+
+ static_assert(!std::integral<T (*)()>);
+ static_assert(!std::integral<T (&)()>);
+ static_assert(!std::integral<T(&&)()>);
+
+ return result;
+}
+
+enum ClassicEnum { a, b, c };
+enum class ScopedEnum { x, y, z };
+struct EmptyStruct {};
+
+constexpr void CheckIntegral() {
+ // standard signed and unsigned integers
+ static_assert(CheckIntegralQualifiers<signed char>());
+ static_assert(CheckIntegralQualifiers<unsigned char>());
+ static_assert(CheckIntegralQualifiers<short>());
+ static_assert(CheckIntegralQualifiers<unsigned short>());
+ static_assert(CheckIntegralQualifiers<int>());
+ static_assert(CheckIntegralQualifiers<unsigned int>());
+ static_assert(CheckIntegralQualifiers<long>());
+ static_assert(CheckIntegralQualifiers<unsigned long>());
+ static_assert(CheckIntegralQualifiers<long long>());
+ static_assert(CheckIntegralQualifiers<unsigned long long>());
+
+ // extended integers
+#ifndef _LIBCPP_HAS_NO_INT128
+ static_assert(CheckIntegralQualifiers<__int128_t>());
+ static_assert(CheckIntegralQualifiers<__uint128_t>());
+#endif
+
+ // bool and char types are also integral
+ static_assert(CheckIntegralQualifiers<wchar_t>());
+ static_assert(CheckIntegralQualifiers<bool>());
+ static_assert(CheckIntegralQualifiers<char>());
+ static_assert(CheckIntegralQualifiers<char8_t>());
+ static_assert(CheckIntegralQualifiers<char16_t>());
+ static_assert(CheckIntegralQualifiers<char32_t>());
+
+ // types that aren't integral
+ static_assert(!std::integral<void>);
+ static_assert(!CheckIntegralQualifiers<float>());
+ static_assert(!CheckIntegralQualifiers<double>());
+ static_assert(!CheckIntegralQualifiers<long double>());
+
+ static_assert(!CheckIntegralQualifiers<ClassicEnum>());
+
+ static_assert(!CheckIntegralQualifiers<ScopedEnum>());
+
+ static_assert(!CheckIntegralQualifiers<EmptyStruct>());
+ static_assert(!CheckIntegralQualifiers<int EmptyStruct::*>());
+ static_assert(!CheckIntegralQualifiers<int (EmptyStruct::*)()>());
+}
+
+template <typename T>
+constexpr bool CheckSignedIntegralQualifiers() {
+ constexpr bool result = std::signed_integral<T>;
+ static_assert(std::signed_integral<const T> == result);
+ static_assert(std::signed_integral<volatile T> == result);
+ static_assert(std::signed_integral<const volatile T> == result);
+
+ static_assert(!std::signed_integral<T&>);
+ static_assert(!std::signed_integral<const T&>);
+ static_assert(!std::signed_integral<volatile T&>);
+ static_assert(!std::signed_integral<const volatile T&>);
+
+ static_assert(!std::signed_integral<T&&>);
+ static_assert(!std::signed_integral<const T&&>);
+ static_assert(!std::signed_integral<volatile T&&>);
+ static_assert(!std::signed_integral<const volatile T&&>);
+
+ static_assert(!std::signed_integral<T*>);
+ static_assert(!std::signed_integral<const T*>);
+ static_assert(!std::signed_integral<volatile T*>);
+ static_assert(!std::signed_integral<const volatile T*>);
+
+ static_assert(!std::signed_integral<T (*)()>);
+ static_assert(!std::signed_integral<T (&)()>);
+ static_assert(!std::signed_integral<T(&&)()>);
+
+ return result;
+}
+
+constexpr void CheckSignedIntegral() {
+ // standard signed integers
+ static_assert(CheckSignedIntegralQualifiers<signed char>());
+ static_assert(CheckSignedIntegralQualifiers<short>());
+ static_assert(CheckSignedIntegralQualifiers<int>());
+ static_assert(CheckSignedIntegralQualifiers<long>());
+ static_assert(CheckSignedIntegralQualifiers<long long>());
+
+ // bool and character *may* be signed
+ static_assert(CheckSignedIntegralQualifiers<wchar_t>() ==
+ std::is_signed_v<wchar_t>);
+ static_assert(CheckSignedIntegralQualifiers<bool>() ==
+ std::is_signed_v<bool>);
+ static_assert(CheckSignedIntegralQualifiers<char>() ==
+ std::is_signed_v<char>);
+ static_assert(CheckSignedIntegralQualifiers<char8_t>() ==
+ std::is_signed_v<char8_t>);
+ static_assert(CheckSignedIntegralQualifiers<char16_t>() ==
+ std::is_signed_v<char16_t>);
+ static_assert(CheckSignedIntegralQualifiers<char32_t>() ==
+ std::is_signed_v<char32_t>);
+
+ // integers that aren't signed integrals
+ static_assert(!CheckSignedIntegralQualifiers<unsigned char>());
+ static_assert(!CheckSignedIntegralQualifiers<unsigned short>());
+ static_assert(!CheckSignedIntegralQualifiers<unsigned int>());
+ static_assert(!CheckSignedIntegralQualifiers<unsigned long>());
+ static_assert(!CheckSignedIntegralQualifiers<unsigned long long>());
+
+ // extended integers
+#ifndef _LIBCPP_HAS_NO_INT128
+ static_assert(CheckSignedIntegralQualifiers<__int128_t>());
+ static_assert(!CheckSignedIntegralQualifiers<__uint128_t>());
+#endif
+
+ // types that aren't even integers shouldn't be signed integers!
+ static_assert(!std::signed_integral<void>);
+ static_assert(!CheckSignedIntegralQualifiers<float>());
+ static_assert(!CheckSignedIntegralQualifiers<double>());
+ static_assert(!CheckSignedIntegralQualifiers<long double>());
+
+ static_assert(!CheckSignedIntegralQualifiers<ClassicEnum>());
+ static_assert(!CheckSignedIntegralQualifiers<ScopedEnum>());
+ static_assert(!CheckSignedIntegralQualifiers<EmptyStruct>());
+ static_assert(!CheckSignedIntegralQualifiers<int EmptyStruct::*>());
+ static_assert(!CheckSignedIntegralQualifiers<int (EmptyStruct::*)()>());
+}
+
+template <typename T>
+constexpr bool CheckUnsignedIntegralQualifiers() {
+ constexpr bool result = std::unsigned_integral<T>;
+ static_assert(std::unsigned_integral<const T> == result);
+ static_assert(std::unsigned_integral<volatile T> == result);
+ static_assert(std::unsigned_integral<const volatile T> == result);
+
+ static_assert(!std::unsigned_integral<T&>);
+ static_assert(!std::unsigned_integral<const T&>);
+ static_assert(!std::unsigned_integral<volatile T&>);
+ static_assert(!std::unsigned_integral<const volatile T&>);
+
+ static_assert(!std::unsigned_integral<T&&>);
+ static_assert(!std::unsigned_integral<const T&&>);
+ static_assert(!std::unsigned_integral<volatile T&&>);
+ static_assert(!std::unsigned_integral<const volatile T&&>);
+
+ static_assert(!std::unsigned_integral<T*>);
+ static_assert(!std::unsigned_integral<const T*>);
+ static_assert(!std::unsigned_integral<volatile T*>);
+ static_assert(!std::unsigned_integral<const volatile T*>);
+
+ static_assert(!std::unsigned_integral<T (*)()>);
+ static_assert(!std::unsigned_integral<T (&)()>);
+ static_assert(!std::unsigned_integral<T(&&)()>);
+
+ return result;
+}
+
+constexpr void CheckUnsignedIntegral() {
+ // standard unsigned types
+ static_assert(CheckUnsignedIntegralQualifiers<unsigned char>());
+ static_assert(CheckUnsignedIntegralQualifiers<unsigned short>());
+ static_assert(CheckUnsignedIntegralQualifiers<unsigned int>());
+ static_assert(CheckUnsignedIntegralQualifiers<unsigned long>());
+ static_assert(CheckUnsignedIntegralQualifiers<unsigned long long>());
+
+ // Whether bool and character types are signed or unsigned is impl-defined
+ static_assert(CheckUnsignedIntegralQualifiers<wchar_t>() ==
+ !std::is_signed_v<wchar_t>);
+ static_assert(CheckUnsignedIntegralQualifiers<bool>() ==
+ !std::is_signed_v<bool>);
+ static_assert(CheckUnsignedIntegralQualifiers<char>() ==
+ !std::is_signed_v<char>);
+ static_assert(CheckUnsignedIntegralQualifiers<char8_t>() ==
+ !std::is_signed_v<char8_t>);
+ static_assert(CheckUnsignedIntegralQualifiers<char16_t>() ==
+ !std::is_signed_v<char16_t>);
+ static_assert(CheckUnsignedIntegralQualifiers<char32_t>() ==
+ !std::is_signed_v<char32_t>);
+
+ // extended integers
+#ifndef _LIBCPP_HAS_NO_INT128
+ static_assert(CheckUnsignedIntegralQualifiers<__uint128_t>());
+ static_assert(!CheckUnsignedIntegralQualifiers<__int128_t>());
+#endif
+
+ // integer types that aren't unsigned integrals
+ static_assert(!CheckUnsignedIntegralQualifiers<signed char>());
+ static_assert(!CheckUnsignedIntegralQualifiers<short>());
+ static_assert(!CheckUnsignedIntegralQualifiers<int>());
+ static_assert(!CheckUnsignedIntegralQualifiers<long>());
+ static_assert(!CheckUnsignedIntegralQualifiers<long long>());
+
+ static_assert(!std::unsigned_integral<void>);
+ static_assert(!CheckUnsignedIntegralQualifiers<float>());
+ static_assert(!CheckUnsignedIntegralQualifiers<double>());
+ static_assert(!CheckUnsignedIntegralQualifiers<long double>());
+
+ static_assert(!CheckUnsignedIntegralQualifiers<ClassicEnum>());
+ static_assert(!CheckUnsignedIntegralQualifiers<ScopedEnum>());
+ static_assert(!CheckUnsignedIntegralQualifiers<EmptyStruct>());
+ static_assert(!CheckUnsignedIntegralQualifiers<int EmptyStruct::*>());
+ static_assert(!CheckUnsignedIntegralQualifiers<int (EmptyStruct::*)()>());
+}
+
+// This overload should never be called. It exists solely to force subsumption.
+template <std::integral I>
+[[nodiscard]] constexpr bool CheckSubsumption(I) {
+ return false;
+}
+
+// clang-format off
+template <std::integral I>
+requires std::signed_integral<I> && (!std::unsigned_integral<I>)
+[[nodiscard]] constexpr bool CheckSubsumption(I) {
+ return std::is_signed_v<I>;
+}
+
+template <std::integral I>
+requires std::unsigned_integral<I> && (!std::signed_integral<I>)
+[[nodiscard]] constexpr bool CheckSubsumption(I) {
+ return std::is_unsigned_v<I>;
+}
+// clang-format on
+
+template <typename T>
+constexpr bool CheckFloatingPointQualifiers() {
+ constexpr bool result = std::floating_point<T>;
+ static_assert(std::floating_point<const T> == result);
+ static_assert(std::floating_point<volatile T> == result);
+ static_assert(std::floating_point<const volatile T> == result);
+
+ static_assert(!std::floating_point<T&>);
+ static_assert(!std::floating_point<const T&>);
+ static_assert(!std::floating_point<volatile T&>);
+ static_assert(!std::floating_point<const volatile T&>);
+
+ static_assert(!std::floating_point<T&&>);
+ static_assert(!std::floating_point<const T&&>);
+ static_assert(!std::floating_point<volatile T&&>);
+ static_assert(!std::floating_point<const volatile T&&>);
+
+ static_assert(!std::floating_point<T*>);
+ static_assert(!std::floating_point<const T*>);
+ static_assert(!std::floating_point<volatile T*>);
+ static_assert(!std::floating_point<const volatile T*>);
+
+ static_assert(!std::floating_point<T (*)()>);
+ static_assert(!std::floating_point<T (&)()>);
+ static_assert(!std::floating_point<T(&&)()>);
+
+ return result;
+}
+
+constexpr void CheckFloatingPoint() {
+ // floating-point types
+ static_assert(CheckFloatingPointQualifiers<float>());
+ static_assert(CheckFloatingPointQualifiers<double>());
+ static_assert(CheckFloatingPointQualifiers<long double>());
+
+ // types that aren't floating-point
+ static_assert(!CheckFloatingPointQualifiers<signed char>());
+ static_assert(!CheckFloatingPointQualifiers<unsigned char>());
+ static_assert(!CheckFloatingPointQualifiers<short>());
+ static_assert(!CheckFloatingPointQualifiers<unsigned short>());
+ static_assert(!CheckFloatingPointQualifiers<int>());
+ static_assert(!CheckFloatingPointQualifiers<unsigned int>());
+ static_assert(!CheckFloatingPointQualifiers<long>());
+ static_assert(!CheckFloatingPointQualifiers<unsigned long>());
+ static_assert(!CheckFloatingPointQualifiers<long long>());
+ static_assert(!CheckFloatingPointQualifiers<unsigned long long>());
+ static_assert(!CheckFloatingPointQualifiers<wchar_t>());
+ static_assert(!CheckFloatingPointQualifiers<bool>());
+ static_assert(!CheckFloatingPointQualifiers<char>());
+ static_assert(!CheckFloatingPointQualifiers<char8_t>());
+ static_assert(!CheckFloatingPointQualifiers<char16_t>());
+ static_assert(!CheckFloatingPointQualifiers<char32_t>());
+ static_assert(!std::floating_point<void>);
+
+ static_assert(!CheckFloatingPointQualifiers<ClassicEnum>());
+ static_assert(!CheckFloatingPointQualifiers<ScopedEnum>());
+ static_assert(!CheckFloatingPointQualifiers<EmptyStruct>());
+ static_assert(!CheckFloatingPointQualifiers<int EmptyStruct::*>());
+ static_assert(!CheckFloatingPointQualifiers<int (EmptyStruct::*)()>());
+}
+} // namespace
+
+int main(int, char**) {
+ CheckIntegral();
+ CheckSignedIntegral();
+ CheckUnsignedIntegral();
+ static_assert(CheckSubsumption(0));
+ static_assert(CheckSubsumption(0U));
+ CheckFloatingPoint();
+ return 0;
+}