| 1 | //===----------------------------------------------------------------------===// |
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| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | |
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| 9 | // UNSUPPORTED: c++03, c++11, c++14, c++17 |
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| 10 | |
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| 11 | // template<class I1, class I2> |
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| 12 | // concept indirectly_swappable; |
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| 13 | |
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| 14 | #include <iterator> |
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| 15 | |
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| 16 | #include "test_macros.h" |
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| 17 | |
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| 18 | template<class T, class ValueType = T> |
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| 19 | struct PointerTo { |
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| 20 | using value_type = ValueType; |
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| 21 | T& operator*() const; |
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| 22 | }; |
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| 23 | |
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| 24 | static_assert(std::indirectly_swappable<PointerTo<int>>); |
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| 25 | static_assert(std::indirectly_swappable<PointerTo<int>, PointerTo<int>>); |
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| 26 | |
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| 27 | struct B; |
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| 28 | |
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| 29 | struct A { |
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| 30 | friend void iter_swap(const PointerTo<A>&, const PointerTo<A>&); |
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| 31 | }; |
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| 32 | |
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| 33 | // Is indirectly swappable. |
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| 34 | struct B { |
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| 35 | friend void iter_swap(const PointerTo<B>&, const PointerTo<B>&); |
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| 36 | friend void iter_swap(const PointerTo<A>&, const PointerTo<B>&); |
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| 37 | friend void iter_swap(const PointerTo<B>&, const PointerTo<A>&); |
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| 38 | }; |
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| 39 | |
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| 40 | // Valid except ranges::iter_swap(i2, i1). |
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| 41 | struct C { |
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| 42 | friend void iter_swap(const PointerTo<C>&, const PointerTo<C>&); |
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| 43 | friend void iter_swap(const PointerTo<A>&, const PointerTo<C>&); |
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| 44 | friend void iter_swap(const PointerTo<C>&, const PointerTo<A>&) = delete; |
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| 45 | }; |
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| 46 | |
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| 47 | // Valid except ranges::iter_swap(i1, i2). |
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| 48 | struct D { |
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| 49 | friend void iter_swap(const PointerTo<D>&, const PointerTo<D>&); |
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| 50 | friend void iter_swap(const PointerTo<A>&, const PointerTo<D>&) = delete; |
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| 51 | friend void iter_swap(const PointerTo<D>&, const PointerTo<A>&); |
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| 52 | }; |
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| 53 | |
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| 54 | // Valid except ranges::iter_swap(i2, i2). |
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| 55 | struct E { |
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| 56 | E operator=(const E&) = delete; |
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| 57 | friend void iter_swap(const PointerTo<E>&, const PointerTo<E>&) = delete; |
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| 58 | friend void iter_swap(const PointerTo<A>&, const PointerTo<E>&); |
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| 59 | friend void iter_swap(const PointerTo<E>&, const PointerTo<A>&); |
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| 60 | }; |
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| 61 | |
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| 62 | struct F { |
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| 63 | friend void iter_swap(const PointerTo<F>&, const PointerTo<F>&) = delete; |
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| 64 | }; |
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| 65 | |
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| 66 | // Valid except ranges::iter_swap(i1, i1). |
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| 67 | struct G { |
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| 68 | friend void iter_swap(const PointerTo<G>&, const PointerTo<G>&); |
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| 69 | friend void iter_swap(const PointerTo<F>&, const PointerTo<G>&); |
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| 70 | friend void iter_swap(const PointerTo<G>&, const PointerTo<F>&); |
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| 71 | }; |
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| 72 | |
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| 73 | |
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| 74 | static_assert( std::indirectly_swappable<PointerTo<A>, PointerTo<B>>); |
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| 75 | static_assert(!std::indirectly_swappable<PointerTo<A>, PointerTo<C>>); |
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| 76 | static_assert(!std::indirectly_swappable<PointerTo<A>, PointerTo<D>>); |
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| 77 | static_assert(!std::indirectly_swappable<PointerTo<A>, PointerTo<E>>); |
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| 78 | static_assert(!std::indirectly_swappable<PointerTo<A>, PointerTo<G>>); |
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| 79 | |
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