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//===----------------------------------------------------------------------===//
//
// 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++03, c++11, c++14, c++17
// UNSUPPORTED: libcpp-no-concepts
// template<class From, class To>
// concept common_reference_with;
#include <concepts>
template <class T, class U>
constexpr bool CheckCommonReferenceWith() noexcept {
static_assert(std::common_reference_with<T, U&>);
static_assert(std::common_reference_with<T, const U&>);
static_assert(std::common_reference_with<T, volatile U&>);
static_assert(std::common_reference_with<T, const volatile U&>);
static_assert(std::common_reference_with<T, U&&>);
static_assert(std::common_reference_with<T, const U&&>);
static_assert(std::common_reference_with<T, volatile U&&>);
static_assert(std::common_reference_with<T, const volatile U&&>);
static_assert(std::common_reference_with<T&, U&&>);
static_assert(std::common_reference_with<T&, const U&&>);
static_assert(std::common_reference_with<T&, volatile U&&>);
static_assert(std::common_reference_with<T&, const volatile U&&>);
static_assert(std::common_reference_with<const T&, U&&>);
static_assert(std::common_reference_with<const T&, const U&&>);
static_assert(std::common_reference_with<const T&, volatile U&&>);
static_assert(std::common_reference_with<const T&, const volatile U&&>);
static_assert(std::common_reference_with<volatile T&, U&&>);
static_assert(std::common_reference_with<volatile T&, const U&&>);
static_assert(std::common_reference_with<volatile T&, volatile U&&>);
static_assert(std::common_reference_with<volatile T&, const volatile U&&>);
static_assert(std::common_reference_with<const volatile T&, U&&>);
static_assert(std::common_reference_with<const volatile T&, const U&&>);
static_assert(std::common_reference_with<const volatile T&, volatile U&&>);
static_assert(
std::common_reference_with<const volatile T&, const volatile U&&>);
return std::common_reference_with<T, U>;
}
namespace BuiltinTypes {
// fundamental types
static_assert(std::common_reference_with<void, void>);
static_assert(CheckCommonReferenceWith<int, int>());
static_assert(CheckCommonReferenceWith<int, long>());
static_assert(CheckCommonReferenceWith<int, unsigned char>());
#ifndef _LIBCPP_HAS_NO_INT128
static_assert(CheckCommonReferenceWith<int, __int128_t>());
#endif
static_assert(CheckCommonReferenceWith<int, double>());
// arrays
static_assert(CheckCommonReferenceWith<int[5], int[5]>());
// pointers (common with void*)
static_assert(CheckCommonReferenceWith<int*, void*>());
static_assert(CheckCommonReferenceWith<int*, const void*>());
static_assert(CheckCommonReferenceWith<int*, volatile void*>());
static_assert(CheckCommonReferenceWith<int*, const volatile void*>());
static_assert(CheckCommonReferenceWith<const int*, void*>());
static_assert(CheckCommonReferenceWith<const int*, const void*>());
static_assert(CheckCommonReferenceWith<const int*, volatile void*>());
static_assert(CheckCommonReferenceWith<const int*, const volatile void*>());
static_assert(CheckCommonReferenceWith<volatile int*, void*>());
static_assert(CheckCommonReferenceWith<volatile int*, const void*>());
static_assert(CheckCommonReferenceWith<volatile int*, volatile void*>());
static_assert(CheckCommonReferenceWith<volatile int*, const volatile void*>());
static_assert(CheckCommonReferenceWith<const volatile int*, void*>());
static_assert(CheckCommonReferenceWith<const volatile int*, const void*>());
static_assert(CheckCommonReferenceWith<const volatile int*, volatile void*>());
static_assert(
CheckCommonReferenceWith<const volatile int*, const volatile void*>());
static_assert(CheckCommonReferenceWith<int (*)(), int (*)()>());
static_assert(CheckCommonReferenceWith<int (*)(), int (*)() noexcept>());
struct S {};
static_assert(CheckCommonReferenceWith<int S::*, int S::*>());
static_assert(CheckCommonReferenceWith<int S::*, const int S::*>());
static_assert(CheckCommonReferenceWith<int (S::*)(), int (S::*)()>());
static_assert(CheckCommonReferenceWith<int (S::*)(), int (S::*)() noexcept>());
static_assert(
CheckCommonReferenceWith<int (S::*)() const, int (S::*)() const>());
static_assert(CheckCommonReferenceWith<int (S::*)() const,
int (S::*)() const noexcept>());
static_assert(
CheckCommonReferenceWith<int (S::*)() volatile, int (S::*)() volatile>());
static_assert(CheckCommonReferenceWith<int (S::*)() volatile,
int (S::*)() volatile noexcept>());
static_assert(CheckCommonReferenceWith<int (S::*)() const volatile,
int (S::*)() const volatile>());
static_assert(CheckCommonReferenceWith<int (S::*)() const volatile,
int (S::*)() const volatile noexcept>());
// nonsense
static_assert(!std::common_reference_with<double, float*>);
static_assert(!std::common_reference_with<int, int[5]>);
static_assert(!std::common_reference_with<int*, long*>);
static_assert(!std::common_reference_with<int*, unsigned int*>);
static_assert(!std::common_reference_with<int (*)(), int (*)(int)>);
static_assert(!std::common_reference_with<int S::*, float S::*>);
static_assert(!std::common_reference_with<int (S::*)(), int (S::*)() const>);
static_assert(!std::common_reference_with<int (S::*)(), int (S::*)() volatile>);
static_assert(
!std::common_reference_with<int (S::*)(), int (S::*)() const volatile>);
static_assert(
!std::common_reference_with<int (S::*)() const, int (S::*)() volatile>);
static_assert(!std::common_reference_with<int (S::*)() const,
int (S::*)() const volatile>);
static_assert(!std::common_reference_with<int (S::*)() volatile,
int (S::*)() const volatile>);
} // namespace BuiltinTypes
namespace NoDefaultCommonReference {
class T {};
static_assert(!std::common_reference_with<T, int>);
static_assert(!std::common_reference_with<int, T>);
static_assert(!std::common_reference_with<T, int[10]>);
static_assert(!std::common_reference_with<T[10], int>);
static_assert(!std::common_reference_with<T*, int*>);
static_assert(!std::common_reference_with<T*, const int*>);
static_assert(!std::common_reference_with<T*, volatile int*>);
static_assert(!std::common_reference_with<T*, const volatile int*>);
static_assert(!std::common_reference_with<const T*, int*>);
static_assert(!std::common_reference_with<volatile T*, int*>);
static_assert(!std::common_reference_with<const volatile T*, int*>);
static_assert(!std::common_reference_with<const T*, const int*>);
static_assert(!std::common_reference_with<const T*, volatile int*>);
static_assert(!std::common_reference_with<const T*, const volatile int*>);
static_assert(!std::common_reference_with<const T*, const int*>);
static_assert(!std::common_reference_with<volatile T*, const int*>);
static_assert(!std::common_reference_with<const volatile T*, const int*>);
static_assert(!std::common_reference_with<volatile T*, const int*>);
static_assert(!std::common_reference_with<volatile T*, volatile int*>);
static_assert(!std::common_reference_with<volatile T*, const volatile int*>);
static_assert(!std::common_reference_with<const T*, volatile int*>);
static_assert(!std::common_reference_with<volatile T*, volatile int*>);
static_assert(!std::common_reference_with<const volatile T*, volatile int*>);
static_assert(!std::common_reference_with<const volatile T*, const int*>);
static_assert(!std::common_reference_with<const volatile T*, volatile int*>);
static_assert(
!std::common_reference_with<const volatile T*, const volatile int*>);
static_assert(!std::common_reference_with<const T*, const volatile int*>);
static_assert(!std::common_reference_with<volatile T*, const volatile int*>);
static_assert(
!std::common_reference_with<const volatile T*, const volatile int*>);
static_assert(!std::common_reference_with<T&, int&>);
static_assert(!std::common_reference_with<T&, const int&>);
static_assert(!std::common_reference_with<T&, volatile int&>);
static_assert(!std::common_reference_with<T&, const volatile int&>);
static_assert(!std::common_reference_with<const T&, int&>);
static_assert(!std::common_reference_with<volatile T&, int&>);
static_assert(!std::common_reference_with<const volatile T&, int&>);
static_assert(!std::common_reference_with<const T&, const int&>);
static_assert(!std::common_reference_with<const T&, volatile int&>);
static_assert(!std::common_reference_with<const T&, const volatile int&>);
static_assert(!std::common_reference_with<const T&, const int&>);
static_assert(!std::common_reference_with<volatile T&, const int&>);
static_assert(!std::common_reference_with<const volatile T&, const int&>);
static_assert(!std::common_reference_with<volatile T&, const int&>);
static_assert(!std::common_reference_with<volatile T&, volatile int&>);
static_assert(!std::common_reference_with<volatile T&, const volatile int&>);
static_assert(!std::common_reference_with<const T&, volatile int&>);
static_assert(!std::common_reference_with<volatile T&, volatile int&>);
static_assert(!std::common_reference_with<const volatile T&, volatile int&>);
static_assert(!std::common_reference_with<const volatile T&, const int&>);
static_assert(!std::common_reference_with<const volatile T&, volatile int&>);
static_assert(
!std::common_reference_with<const volatile T&, const volatile int&>);
static_assert(!std::common_reference_with<const T&, const volatile int&>);
static_assert(!std::common_reference_with<volatile T&, const volatile int&>);
static_assert(
!std::common_reference_with<const volatile T&, const volatile int&>);
static_assert(!std::common_reference_with<T&, int&&>);
static_assert(!std::common_reference_with<T&, const int&&>);
static_assert(!std::common_reference_with<T&, volatile int&&>);
static_assert(!std::common_reference_with<T&, const volatile int&&>);
static_assert(!std::common_reference_with<const T&, int&&>);
static_assert(!std::common_reference_with<volatile T&, int&&>);
static_assert(!std::common_reference_with<const volatile T&, int&&>);
static_assert(!std::common_reference_with<const T&, const int&&>);
static_assert(!std::common_reference_with<const T&, volatile int&&>);
static_assert(!std::common_reference_with<const T&, const volatile int&&>);
static_assert(!std::common_reference_with<const T&, const int&&>);
static_assert(!std::common_reference_with<volatile T&, const int&&>);
static_assert(!std::common_reference_with<const volatile T&, const int&&>);
static_assert(!std::common_reference_with<volatile T&, const int&&>);
static_assert(!std::common_reference_with<volatile T&, volatile int&&>);
static_assert(!std::common_reference_with<volatile T&, const volatile int&&>);
static_assert(!std::common_reference_with<const T&, volatile int&&>);
static_assert(!std::common_reference_with<volatile T&, volatile int&&>);
static_assert(!std::common_reference_with<const volatile T&, volatile int&&>);
static_assert(!std::common_reference_with<const volatile T&, const int&&>);
static_assert(!std::common_reference_with<const volatile T&, volatile int&&>);
static_assert(
!std::common_reference_with<const volatile T&, const volatile int&&>);
static_assert(!std::common_reference_with<const T&, const volatile int&&>);
static_assert(!std::common_reference_with<volatile T&, const volatile int&&>);
static_assert(
!std::common_reference_with<const volatile T&, const volatile int&&>);
static_assert(!std::common_reference_with<T&&, int&>);
static_assert(!std::common_reference_with<T&&, const int&>);
static_assert(!std::common_reference_with<T&&, volatile int&>);
static_assert(!std::common_reference_with<T&&, const volatile int&>);
static_assert(!std::common_reference_with<const T&&, int&>);
static_assert(!std::common_reference_with<volatile T&&, int&>);
static_assert(!std::common_reference_with<const volatile T&&, int&>);
static_assert(!std::common_reference_with<const T&&, const int&>);
static_assert(!std::common_reference_with<const T&&, volatile int&>);
static_assert(!std::common_reference_with<const T&&, const volatile int&>);
static_assert(!std::common_reference_with<const T&&, const int&>);
static_assert(!std::common_reference_with<volatile T&&, const int&>);
static_assert(!std::common_reference_with<const volatile T&&, const int&>);
static_assert(!std::common_reference_with<volatile T&&, const int&>);
static_assert(!std::common_reference_with<volatile T&&, volatile int&>);
static_assert(!std::common_reference_with<volatile T&&, const volatile int&>);
static_assert(!std::common_reference_with<const T&&, volatile int&>);
static_assert(!std::common_reference_with<volatile T&&, volatile int&>);
static_assert(!std::common_reference_with<const volatile T&&, volatile int&>);
static_assert(!std::common_reference_with<const volatile T&&, const int&>);
static_assert(!std::common_reference_with<const volatile T&&, volatile int&>);
static_assert(
!std::common_reference_with<const volatile T&&, const volatile int&>);
static_assert(!std::common_reference_with<const T&&, const volatile int&>);
static_assert(!std::common_reference_with<volatile T&&, const volatile int&>);
static_assert(
!std::common_reference_with<const volatile T&&, const volatile int&>);
static_assert(!std::common_reference_with<T&&, int&&>);
static_assert(!std::common_reference_with<T&&, const int&&>);
static_assert(!std::common_reference_with<T&&, volatile int&&>);
static_assert(!std::common_reference_with<T&&, const volatile int&&>);
static_assert(!std::common_reference_with<const T&&, int&&>);
static_assert(!std::common_reference_with<volatile T&&, int&&>);
static_assert(!std::common_reference_with<const volatile T&&, int&&>);
static_assert(!std::common_reference_with<const T&&, const int&&>);
static_assert(!std::common_reference_with<const T&&, volatile int&&>);
static_assert(!std::common_reference_with<const T&&, const volatile int&&>);
static_assert(!std::common_reference_with<const T&&, const int&&>);
static_assert(!std::common_reference_with<volatile T&&, const int&&>);
static_assert(!std::common_reference_with<const volatile T&&, const int&&>);
static_assert(!std::common_reference_with<volatile T&&, const int&&>);
static_assert(!std::common_reference_with<volatile T&&, volatile int&&>);
static_assert(!std::common_reference_with<volatile T&&, const volatile int&&>);
static_assert(!std::common_reference_with<const T&&, volatile int&&>);
static_assert(!std::common_reference_with<volatile T&&, volatile int&&>);
static_assert(!std::common_reference_with<const volatile T&&, volatile int&&>);
static_assert(!std::common_reference_with<const volatile T&&, const int&&>);
static_assert(!std::common_reference_with<const volatile T&&, volatile int&&>);
static_assert(
!std::common_reference_with<const volatile T&&, const volatile int&&>);
static_assert(!std::common_reference_with<const T&&, const volatile int&&>);
static_assert(!std::common_reference_with<volatile T&&, const volatile int&&>);
static_assert(
!std::common_reference_with<const volatile T&&, const volatile int&&>);
} // namespace NoDefaultCommonReference
struct BadBasicCommonReference {
// This test is ill-formed, NDR. If it ever blows up in our faces: that's a good thing.
// In the meantime, the test should be included. If compiler support is added, then an include guard
// should be placed so the test doesn't get deleted.
operator int() const;
operator int&();
};
static_assert(std::convertible_to<BadBasicCommonReference, int>);
static_assert(std::convertible_to<BadBasicCommonReference, int&>);
namespace std {
template <template <class> class X, template <class> class Y>
struct basic_common_reference<BadBasicCommonReference, int, X, Y> {
using type = BadBasicCommonReference&;
};
template <template <class> class X, template <class> class Y>
struct basic_common_reference<int, BadBasicCommonReference, X, Y> {
using type = int&;
};
} // namespace std
static_assert(!std::common_reference_with<BadBasicCommonReference, int>);
struct StructNotConvertibleToCommonReference {
explicit(false) StructNotConvertibleToCommonReference(int);
};
static_assert(std::convertible_to<int, StructNotConvertibleToCommonReference>);
namespace std {
template <template <class> class X, template <class> class Y>
struct basic_common_reference<StructNotConvertibleToCommonReference, int, X,
Y> {
using type = int&;
};
template <template <class> class X, template <class> class Y>
struct basic_common_reference<int, StructNotConvertibleToCommonReference, X,
Y> {
using type = int&;
};
} // namespace std
static_assert(
!std::common_reference_with<StructNotConvertibleToCommonReference, int>);
struct IntNotConvertibleToCommonReference {
operator int&() const;
};
namespace std {
template <template <class> class X, template <class> class Y>
struct basic_common_reference<IntNotConvertibleToCommonReference, int, X, Y> {
using type = int&;
};
template <template <class> class X, template <class> class Y>
struct basic_common_reference<int, IntNotConvertibleToCommonReference, X, Y> {
using type = int&;
};
} // namespace std
static_assert(
!std::common_reference_with<StructNotConvertibleToCommonReference, int>);
struct HasCommonReference {
explicit(false) HasCommonReference(int);
operator int&() const;
};
namespace std {
template <template <class> class X, template <class> class Y>
struct basic_common_reference<HasCommonReference, int, X, Y> {
using type = int&;
};
template <template <class> class X, template <class> class Y>
struct basic_common_reference<int, HasCommonReference, X, Y> {
using type = int&;
};
} // namespace std
static_assert(!std::common_reference_with<HasCommonReference, int>);
static_assert(std::common_reference_with<HasCommonReference, int&>);
int main(int, char**) { return 0; }
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