617b446176
[P1789R3](https://isocpp.org/files/papers/P1789R3.pdf) was accepted for C++26 through LWG motion 14 at the 2025 Kona meeting. This patch implements it, along with tests and documentation changes. Closes #167268 --------- Co-authored-by: Tsche <che@pydong.org>
59 lines
2.1 KiB
C++
59 lines
2.1 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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// REQUIRES: std-at-least-c++26
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// <utility>
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// template<class T, T... Values>
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// struct tuple_size<integer_sequence<T, Values...>>;
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// template<size_t I, class T, T... Values>
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// struct tuple_element<I, integer_sequence<T, Values...>>;
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// template<size_t I, class T, T... Values>
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// struct tuple_element<I, const integer_sequence<T, Values...>>;
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// template<size_t I, class T, T... Values>
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// constexpr T get(integer_sequence<T, Values...>) noexcept;
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#include <cassert>
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#include <concepts>
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#include <tuple>
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#include <type_traits>
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#include <utility>
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void test() {
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// std::tuple_size_v
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using empty = std::integer_sequence<int>;
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static_assert(std::tuple_size_v<empty> == 0);
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static_assert(std::tuple_size_v<const empty> == 0);
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using size4 = std::integer_sequence<int, 9, 8, 7, 2>;
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static_assert(std::tuple_size_v<size4> == 4);
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static_assert(std::tuple_size_v<const size4> == 4);
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// std::tuple_element_t
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static_assert(std::is_same_v<std::tuple_element_t<0, size4>, int>);
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static_assert(std::is_same_v<std::tuple_element_t<1, size4>, int>);
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static_assert(std::is_same_v<std::tuple_element_t<2, size4>, int>);
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static_assert(std::is_same_v<std::tuple_element_t<3, size4>, int>);
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static_assert(std::is_same_v<std::tuple_element_t<0, const size4>, int>);
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static_assert(std::is_same_v<std::tuple_element_t<1, const size4>, int>);
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static_assert(std::is_same_v<std::tuple_element_t<2, const size4>, int>);
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static_assert(std::is_same_v<std::tuple_element_t<3, const size4>, int>);
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// std::get
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constexpr static size4 seq4;
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constexpr std::same_as<int> decltype(auto) elt0 = get<0>(seq4);
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static_assert(elt0 == 9);
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static_assert(get<1>(seq4) == 8);
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static_assert(get<2>(seq4) == 7);
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static_assert(get<3>(seq4) == 2);
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static_assert(noexcept(get<0>(seq4)));
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}
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