| 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 F, class I> |
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| 12 | // concept indirectly_unary_invocable; |
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| 13 | |
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| 14 | #include <iterator> |
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| 15 | #include <concepts> |
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| 16 | |
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| 17 | #include "indirectly_readable.h" |
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| 18 | #include "test_macros.h" |
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| 19 | |
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| 20 | using It = IndirectlyReadable<struct Token>; |
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| 21 | using R1 = T1<struct ReturnToken>; |
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| 22 | using R2 = T2<struct ReturnToken>; |
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| 23 | |
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| 24 | template <class I> |
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| 25 | struct GoodInvocable { |
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| 26 | R1 operator()(std::iter_value_t<I>&) const; |
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| 27 | R2 operator()(std::iter_reference_t<I>) const; |
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| 28 | R2 operator()(std::iter_common_reference_t<I>) const; |
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| 29 | }; |
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| 30 | |
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| 31 | // Should work when all constraints are satisfied |
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| 32 | static_assert(std::indirectly_unary_invocable<GoodInvocable<It>, It>); |
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| 33 | |
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| 34 | // Should fail when the iterator is not indirectly_readable |
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| 35 | struct NotIndirectlyReadable { }; |
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| 36 | static_assert(!std::indirectly_unary_invocable<GoodInvocable<NotIndirectlyReadable>, NotIndirectlyReadable>); |
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| 37 | |
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| 38 | // Should fail when the invocable is not copy constructible |
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| 39 | struct BadInvocable1 { |
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| 40 | BadInvocable1(BadInvocable1 const&) = delete; |
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| 41 | template <class T> R1 operator()(T const&) const; |
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| 42 | }; |
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| 43 | static_assert(!std::indirectly_unary_invocable<BadInvocable1, It>); |
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| 44 | |
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| 45 | // Should fail when the invocable can't be called with (iter_value_t&) |
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| 46 | struct BadInvocable2 { |
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| 47 | template <class T> R1 operator()(T const&) const; |
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| 48 | R1 operator()(std::iter_value_t<It>&) const = delete; |
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| 49 | }; |
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| 50 | static_assert(!std::indirectly_unary_invocable<BadInvocable2, It>); |
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| 51 | |
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| 52 | // Should fail when the invocable can't be called with (iter_reference_t) |
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| 53 | struct BadInvocable3 { |
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| 54 | template <class T> R1 operator()(T const&) const; |
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| 55 | R1 operator()(std::iter_reference_t<It>) const = delete; |
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| 56 | }; |
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| 57 | static_assert(!std::indirectly_unary_invocable<BadInvocable3, It>); |
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| 58 | |
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| 59 | // This case was made valid by P2997R1. |
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| 60 | struct GoodInvocable4 { |
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| 61 | template <class T> |
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| 62 | R1 operator()(T const&) const; |
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| 63 | R1 operator()(std::iter_common_reference_t<It>) const = delete; |
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| 64 | }; |
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| 65 | static_assert(std::indirectly_unary_invocable<GoodInvocable4, It>); |
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| 66 | |
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| 67 | // Should fail when the invocable doesn't have a common reference between its return types |
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| 68 | struct BadInvocable5 { |
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| 69 | R1 operator()(std::iter_value_t<It>&) const; |
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| 70 | struct Unrelated { }; |
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| 71 | Unrelated operator()(std::iter_reference_t<It>) const; |
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| 72 | R1 operator()(std::iter_common_reference_t<It>) const; |
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| 73 | }; |
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| 74 | static_assert(!std::indirectly_unary_invocable<BadInvocable5, It>); |
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| 75 | |
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| 76 | // Various tests with callables |
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| 77 | struct S; |
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| 78 | static_assert(std::indirectly_unary_invocable<int (*)(int), int*>); |
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| 79 | static_assert(std::indirectly_unary_invocable<int (&)(int), int*>); |
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| 80 | static_assert(std::indirectly_unary_invocable<int S::*, S*>); |
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| 81 | static_assert(std::indirectly_unary_invocable<int (S::*)(), S*>); |
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| 82 | static_assert(std::indirectly_unary_invocable<int (S::*)() const, S*>); |
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| 83 | static_assert(std::indirectly_unary_invocable<void(*)(int), int*>); |
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| 84 | |
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| 85 | static_assert(!std::indirectly_unary_invocable<int(int), int*>); // not move constructible |
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| 86 | static_assert(!std::indirectly_unary_invocable<int (*)(int*, int*), int*>); |
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| 87 | static_assert(!std::indirectly_unary_invocable<int (&)(int*, int*), int*>); |
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| 88 | static_assert(!std::indirectly_unary_invocable<int (S::*)(int*), S*>); |
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| 89 | static_assert(!std::indirectly_unary_invocable<int (S::*)(int*) const, S*>); |
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| 90 | |
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| 91 | // Test ADL-proofing (P2538R1) |
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| 92 | #if TEST_STD_VER >= 26 || defined(_LIBCPP_VERSION) |
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| 93 | struct Incomplete; |
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| 94 | template<class T> struct Holder { T t; }; |
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| 95 | struct HolderIncompletePred { bool operator()(Holder<Incomplete>*) const; }; |
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| 96 | static_assert(std::indirectly_unary_invocable<HolderIncompletePred, Holder<Incomplete>**>); |
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| 97 | static_assert(!std::indirectly_unary_invocable<Holder<Incomplete>*, Holder<Incomplete>**>); |
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| 98 | #endif |
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| 99 | |
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