forked from OSchip/llvm-project
49 lines
1.7 KiB
C++
49 lines
1.7 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, c++17
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// UNSUPPORTED: libcpp-no-concepts
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// UNSUPPORTED: libcpp-has-no-incomplete-ranges
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// <ranges>
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// template<class T>
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// inline constexpr bool enable_view = ...;
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#include <ranges>
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#include "test_macros.h"
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// Doesn't derive from view_base
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struct Empty { };
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static_assert(!std::ranges::enable_view<Empty>);
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// Derives from view_base, but privately
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struct PrivateViewBase : private std::ranges::view_base { };
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static_assert(!std::ranges::enable_view<PrivateViewBase>);
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// Derives from view_base, but specializes enable_view to false
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struct EnableViewFalse : std::ranges::view_base { };
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namespace std::ranges { template <> constexpr bool enable_view<EnableViewFalse> = false; }
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static_assert(!std::ranges::enable_view<EnableViewFalse>);
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// Derives from view_base
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struct PublicViewBase : std::ranges::view_base { };
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static_assert(std::ranges::enable_view<PublicViewBase>);
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// Does not derive from view_base, but specializes enable_view to true
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struct EnableViewTrue { };
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namespace std::ranges { template <> constexpr bool enable_view<EnableViewTrue> = true; }
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static_assert(std::ranges::enable_view<EnableViewTrue>);
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// Make sure that enable_view is a bool, not some other contextually-convertible-to-bool type.
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ASSERT_SAME_TYPE(decltype(std::ranges::enable_view<Empty>), const bool);
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ASSERT_SAME_TYPE(decltype(std::ranges::enable_view<PublicViewBase>), const bool);
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