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-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 // UNSUPPORTED: c++03, c++11, c++14, c++17 10 // UNSUPPORTED: libcpp-no-concepts 11 // UNSUPPORTED: libcpp-has-no-incomplete-ranges 12 13 // <ranges> 14 15 // template<class T> 16 // inline constexpr bool enable_view = ...; 17 18 #include <ranges> 19 20 #include "test_macros.h" 21 22 // Doesn't derive from view_base 23 struct Empty { }; 24 static_assert(!std::ranges::enable_view<Empty>); 25 static_assert(!std::ranges::enable_view<Empty&>); 26 static_assert(!std::ranges::enable_view<Empty&&>); 27 static_assert(!std::ranges::enable_view<const Empty>); 28 static_assert(!std::ranges::enable_view<const Empty&>); 29 static_assert(!std::ranges::enable_view<const Empty&&>); 30 31 // Derives from view_base, but privately 32 struct PrivateViewBase : private std::ranges::view_base { }; 33 static_assert(!std::ranges::enable_view<PrivateViewBase>); 34 static_assert(!std::ranges::enable_view<PrivateViewBase&>); 35 static_assert(!std::ranges::enable_view<PrivateViewBase&&>); 36 static_assert(!std::ranges::enable_view<const PrivateViewBase>); 37 static_assert(!std::ranges::enable_view<const PrivateViewBase&>); 38 static_assert(!std::ranges::enable_view<const PrivateViewBase&&>); 39 40 // Derives from view_base, but specializes enable_view to false 41 struct EnableViewFalse : std::ranges::view_base { }; 42 template <> constexpr bool std::ranges::enable_view<EnableViewFalse> = false; 43 static_assert(!std::ranges::enable_view<EnableViewFalse>); 44 static_assert(!std::ranges::enable_view<EnableViewFalse&>); 45 static_assert(!std::ranges::enable_view<EnableViewFalse&&>); 46 static_assert(std::ranges::enable_view<const EnableViewFalse>); 47 static_assert(!std::ranges::enable_view<const EnableViewFalse&>); 48 static_assert(!std::ranges::enable_view<const EnableViewFalse&&>); 49 50 // Derives from view_base 51 struct PublicViewBase : std::ranges::view_base { }; 52 static_assert(std::ranges::enable_view<PublicViewBase>); 53 static_assert(!std::ranges::enable_view<PublicViewBase&>); 54 static_assert(!std::ranges::enable_view<PublicViewBase&&>); 55 static_assert(std::ranges::enable_view<const PublicViewBase>); 56 static_assert(!std::ranges::enable_view<const PublicViewBase&>); 57 static_assert(!std::ranges::enable_view<const PublicViewBase&&>); 58 59 // Does not derive from view_base, but specializes enable_view to true 60 struct EnableViewTrue { }; 61 template <> constexpr bool std::ranges::enable_view<EnableViewTrue> = true; 62 static_assert(std::ranges::enable_view<EnableViewTrue>); 63 static_assert(!std::ranges::enable_view<EnableViewTrue&>); 64 static_assert(!std::ranges::enable_view<EnableViewTrue&&>); 65 static_assert(!std::ranges::enable_view<const EnableViewTrue>); 66 static_assert(!std::ranges::enable_view<const EnableViewTrue&>); 67 static_assert(!std::ranges::enable_view<const EnableViewTrue&&>); 68 69 // Make sure that enable_view is a bool, not some other contextually-convertible-to-bool type. 70 ASSERT_SAME_TYPE(decltype(std::ranges::enable_view<Empty>), const bool); 71 ASSERT_SAME_TYPE(decltype(std::ranges::enable_view<PublicViewBase>), const bool); 72 73 struct V1 : std::ranges::view_interface<V1> {}; 74 static_assert(std::ranges::enable_view<V1>); 75 static_assert(!std::ranges::enable_view<V1&>); 76 static_assert(!std::ranges::enable_view<V1&&>); 77 static_assert(std::ranges::enable_view<const V1>); 78 static_assert(!std::ranges::enable_view<const V1&>); 79 static_assert(!std::ranges::enable_view<const V1&&>); 80 81 struct V2 : std::ranges::view_interface<V1>, std::ranges::view_interface<V2> {}; 82 static_assert(!std::ranges::enable_view<V2>); 83 static_assert(!std::ranges::enable_view<V2&>); 84 static_assert(!std::ranges::enable_view<V2&&>); 85 static_assert(!std::ranges::enable_view<const V2>); 86 static_assert(!std::ranges::enable_view<const V2&>); 87 static_assert(!std::ranges::enable_view<const V2&&>); 88 89 struct V3 : std::ranges::view_interface<V1> {}; 90 static_assert(std::ranges::enable_view<V3>); 91 static_assert(!std::ranges::enable_view<V3&>); 92 static_assert(!std::ranges::enable_view<V3&&>); 93 static_assert(std::ranges::enable_view<const V3>); 94 static_assert(!std::ranges::enable_view<const V3&>); 95 static_assert(!std::ranges::enable_view<const V3&&>); 96 97 struct PrivateInherit : private std::ranges::view_interface<PrivateInherit> {}; 98 static_assert(!std::ranges::enable_view<PrivateInherit>); 99 100 // ADL-proof 101 struct Incomplete; 102 template<class T> struct Holder { T t; }; 103 static_assert(!std::ranges::enable_view<Holder<Incomplete>*>); 104 105 static_assert(!std::ranges::enable_view<void>); 106