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