[libcxx] adds [concepts.arithmetic]

Implements parts of: * P0898R3 Standard Library Concepts * P1754 Rename concepts to standard_case for C++20, while we still can Differential Revision: https://reviews.llvm.org/D88131
llvm · Feb 10, 2021 · bee7b07 · bee7b07
1 parent 68945a8
commit bee7b07
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Showing 4 changed files with 361 additions and 2 deletions.
diff --git a/libcxx/include/concepts b/libcxx/include/concepts
@@ -165,6 +165,19 @@ concept convertible_to =
     static_cast<_To>(__f());
   };
 
+// [concepts.arithmetic], arithmetic concepts
+template<class _Tp>
+concept integral = is_integral_v<_Tp>;
+
+template<class _Tp>
+concept signed_integral = integral<_Tp> && is_signed_v<_Tp>;
+
+template<class _Tp>
+concept unsigned_integral = integral<_Tp> && !signed_integral<_Tp>;
+
+template<class _Tp>
+concept floating_point = is_floating_point_v<_Tp>;
+
 // [concept.destructible]
 
 template<class _Tp>

diff --git a/libcxx/test/std/concepts/lang/arithmetic.pass.cpp b/libcxx/test/std/concepts/lang/arithmetic.pass.cpp
@@ -0,0 +1,346 @@
+//===----------------------------------------------------------------------===//
+//
+// 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;
+}
diff --git a/libcxx/test/std/concepts/lang/copyconstructible.compile.pass.cpp b/libcxx/test/std/concepts/lang/copyconstructible.compile.pass.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
+// UNSUPPORTED: c++03, c++11, c++14, c++17
 // UNSUPPORTED: libcpp-no-concepts
 
 // template<class T>

diff --git a/libcxx/test/std/concepts/lang/moveconstructible.compile.pass.cpp b/libcxx/test/std/concepts/lang/moveconstructible.compile.pass.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
+// UNSUPPORTED: c++03, c++11, c++14, c++17
 // UNSUPPORTED: libcpp-no-concepts
 
 // template<class T>