f2f4b557aa
This is a follow-up and depends on #139368 being merged first. Implements [P2944R3](https://wg21.link/P2944R3) partially, which adds constrained comparisons to `std::variant` Closes #136769 Depends on #139368 # References [variant.relops](https://wg21.link/variant.relops)
90 lines
3.1 KiB
C++
90 lines
3.1 KiB
C++
//===----------------------------------------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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// UNSUPPORTED: c++03, c++11, c++14
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// <variant>
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// template <class ...Types>
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// constexpr bool
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// operator==(variant<Types...> const&, variant<Types...> const&) noexcept;
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//
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// template <class ...Types>
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// constexpr bool
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// operator!=(variant<Types...> const&, variant<Types...> const&) noexcept;
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//
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// template <class ...Types>
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// constexpr bool
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// operator<(variant<Types...> const&, variant<Types...> const&) noexcept;
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//
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// template <class ...Types>
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// constexpr bool
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// operator>(variant<Types...> const&, variant<Types...> const&) noexcept;
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//
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// template <class ...Types>
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// constexpr bool
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// operator<=(variant<Types...> const&, variant<Types...> const&) noexcept;
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//
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// template <class ...Types>
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// constexpr bool
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// operator>=(variant<Types...> const&, variant<Types...> const&) noexcept;
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#include <cassert>
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#include <type_traits>
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#include <utility>
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#include <variant>
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#include "test_macros.h"
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#if TEST_STD_VER >= 26
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// expected-no-diagnostics
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#else
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struct MyBoolExplicit {
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bool value;
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constexpr explicit MyBoolExplicit(bool v) : value(v) {}
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constexpr explicit operator bool() const noexcept { return value; }
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};
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struct ComparesToMyBoolExplicit {
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int value = 0;
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};
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inline constexpr MyBoolExplicit operator==(const ComparesToMyBoolExplicit& LHS, const ComparesToMyBoolExplicit& RHS) noexcept {
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return MyBoolExplicit(LHS.value == RHS.value);
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}
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inline constexpr MyBoolExplicit operator!=(const ComparesToMyBoolExplicit& LHS, const ComparesToMyBoolExplicit& RHS) noexcept {
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return MyBoolExplicit(LHS.value != RHS.value);
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}
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inline constexpr MyBoolExplicit operator<(const ComparesToMyBoolExplicit& LHS, const ComparesToMyBoolExplicit& RHS) noexcept {
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return MyBoolExplicit(LHS.value < RHS.value);
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}
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inline constexpr MyBoolExplicit operator<=(const ComparesToMyBoolExplicit& LHS, const ComparesToMyBoolExplicit& RHS) noexcept {
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return MyBoolExplicit(LHS.value <= RHS.value);
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}
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inline constexpr MyBoolExplicit operator>(const ComparesToMyBoolExplicit& LHS, const ComparesToMyBoolExplicit& RHS) noexcept {
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return MyBoolExplicit(LHS.value > RHS.value);
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}
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inline constexpr MyBoolExplicit operator>=(const ComparesToMyBoolExplicit& LHS, const ComparesToMyBoolExplicit& RHS) noexcept {
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return MyBoolExplicit(LHS.value >= RHS.value);
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}
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void test() {
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using V = std::variant<int, ComparesToMyBoolExplicit>;
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V v1(42);
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V v2(101);
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// expected-error-re@variant:* 6 {{static assertion failed{{.*}}the relational operator does not return a type which is implicitly convertible to bool}}
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// expected-error@variant:* 6 {{no viable conversion}}
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(void)(v1 == v2); // expected-note {{here}}
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(void)(v1 != v2); // expected-note {{here}}
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(void)(v1 < v2); // expected-note {{here}}
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(void)(v1 <= v2); // expected-note {{here}}
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(void)(v1 > v2); // expected-note {{here}}
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(void)(v1 >= v2); // expected-note {{here}}
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}
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#endif
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