106 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 LHS, class RHS>12// concept assignable_from =13// std::is_lvalue_reference_v<LHS> &&14// std::common_reference_with<15// const std::remove_reference_t<LHS>&,16// const std::remove_reference_t<RHS>&> &&17// requires (LHS lhs, RHS&& rhs) {18// { lhs = std::forward<RHS>(rhs) } -> std::same_as<LHS>;19// };20 21#include <concepts>22#include <type_traits>23 24#include "MoveOnly.h"25 26struct NoCommonRef {27 NoCommonRef& operator=(const int&);28};29static_assert(std::is_assignable_v<NoCommonRef&, const int&>);30static_assert(!std::assignable_from<NoCommonRef&, const int&>); // no common reference type31 32struct Base {};33struct Derived : Base {};34static_assert(!std::assignable_from<Base*, Derived*>);35static_assert( std::assignable_from<Base*&, Derived*>);36static_assert( std::assignable_from<Base*&, Derived*&>);37static_assert( std::assignable_from<Base*&, Derived*&&>);38static_assert( std::assignable_from<Base*&, Derived* const>);39static_assert( std::assignable_from<Base*&, Derived* const&>);40static_assert( std::assignable_from<Base*&, Derived* const&&>);41static_assert(!std::assignable_from<Base*&, const Derived*>);42static_assert(!std::assignable_from<Base*&, const Derived*&>);43static_assert(!std::assignable_from<Base*&, const Derived*&&>);44static_assert(!std::assignable_from<Base*&, const Derived* const>);45static_assert(!std::assignable_from<Base*&, const Derived* const&>);46static_assert(!std::assignable_from<Base*&, const Derived* const&&>);47static_assert( std::assignable_from<const Base*&, Derived*>);48static_assert( std::assignable_from<const Base*&, Derived*&>);49static_assert( std::assignable_from<const Base*&, Derived*&&>);50static_assert( std::assignable_from<const Base*&, Derived* const>);51static_assert( std::assignable_from<const Base*&, Derived* const&>);52static_assert( std::assignable_from<const Base*&, Derived* const&&>);53static_assert( std::assignable_from<const Base*&, const Derived*>);54static_assert( std::assignable_from<const Base*&, const Derived*&>);55static_assert( std::assignable_from<const Base*&, const Derived*&&>);56static_assert( std::assignable_from<const Base*&, const Derived* const>);57static_assert( std::assignable_from<const Base*&, const Derived* const&>);58static_assert( std::assignable_from<const Base*&, const Derived* const&&>);59 60struct VoidResultType {61 void operator=(const VoidResultType&);62};63static_assert(std::is_assignable_v<VoidResultType&, const VoidResultType&>);64static_assert(!std::assignable_from<VoidResultType&, const VoidResultType&>);65 66struct ValueResultType {67 ValueResultType operator=(const ValueResultType&);68};69static_assert(std::is_assignable_v<ValueResultType&, const ValueResultType&>);70static_assert(!std::assignable_from<ValueResultType&, const ValueResultType&>);71 72struct Locale {73 const Locale& operator=(const Locale&);74};75static_assert(std::is_assignable_v<Locale&, const Locale&>);76static_assert(!std::assignable_from<Locale&, const Locale&>);77 78struct Tuple {79 Tuple& operator=(const Tuple&);80 const Tuple& operator=(const Tuple&) const;81};82static_assert(!std::assignable_from<Tuple, const Tuple&>);83static_assert( std::assignable_from<Tuple&, const Tuple&>);84static_assert(!std::assignable_from<Tuple&&, const Tuple&>);85static_assert(!std::assignable_from<const Tuple, const Tuple&>);86static_assert( std::assignable_from<const Tuple&, const Tuple&>);87static_assert(!std::assignable_from<const Tuple&&, const Tuple&>);88 89// Finally, check a few simple cases.90static_assert( std::assignable_from<int&, int>);91static_assert( std::assignable_from<int&, int&>);92static_assert( std::assignable_from<int&, int&&>);93static_assert(!std::assignable_from<const int&, int>);94static_assert(!std::assignable_from<const int&, int&>);95static_assert(!std::assignable_from<const int&, int&&>);96static_assert( std::assignable_from<volatile int&, int>);97static_assert( std::assignable_from<volatile int&, int&>);98static_assert( std::assignable_from<volatile int&, int&&>);99static_assert(!std::assignable_from<int(&)[10], int>);100static_assert(!std::assignable_from<int(&)[10], int(&)[10]>);101static_assert( std::assignable_from<MoveOnly&, MoveOnly>);102static_assert(!std::assignable_from<MoveOnly&, MoveOnly&>);103static_assert( std::assignable_from<MoveOnly&, MoveOnly&&>);104static_assert(!std::assignable_from<void, int>);105static_assert(!std::assignable_from<void, void>);106