a2b3ab8f77
- implement `std::ranges::split_view` (last c++20 view) - Work in process on testing iterator/sentinel, but since we are getting closer to the deadline, I'd like to send the review early Differential Revision: https://reviews.llvm.org/D142063
104 lines
3.2 KiB
C++
104 lines
3.2 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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// constexpr V base() const & requires copy_constructible<V> { return base_; }
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// constexpr V base() && { return std::move(base_); }
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#include <cassert>
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#include <ranges>
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#include <type_traits>
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#include <utility>
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#include "MoveOnly.h"
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struct View : std::ranges::view_base {
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int i;
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int* begin() const;
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int* end() const;
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};
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struct MoveOnlyView : View {
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MoveOnly mo;
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};
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template <class T>
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concept HasBase = requires(T&& t) { std::forward<T>(t).base(); };
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static_assert(HasBase<std::ranges::split_view<View, View> const&>);
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static_assert(HasBase<std::ranges::split_view<View, View>&&>);
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static_assert(!HasBase<std::ranges::split_view<MoveOnlyView, View> const&>);
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static_assert(HasBase<std::ranges::split_view<MoveOnlyView, View>&&>);
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constexpr bool test() {
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// const &
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{
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const std::ranges::split_view<View, View> sv{View{{}, 5}, View{{}, 0}};
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std::same_as<View> decltype(auto) v = sv.base();
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assert(v.i == 5);
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}
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// &
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{
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std::ranges::split_view<View, View> sv{View{{}, 5}, View{{}, 0}};
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std::same_as<View> decltype(auto) v = sv.base();
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assert(v.i == 5);
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}
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// &&
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{
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std::ranges::split_view<View, View> sv{View{{}, 5}, View{{}, 0}};
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std::same_as<View> decltype(auto) v = std::move(sv).base();
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assert(v.i == 5);
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}
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// const &&
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{
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std::ranges::split_view<View, View> sv{View{{}, 5}, View{{}, 0}};
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std::same_as<View> decltype(auto) v = std::move(sv).base();
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assert(v.i == 5);
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}
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// move only
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{
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std::ranges::split_view<MoveOnlyView, View> sv{MoveOnlyView{{}, 5}, View{{}, 0}};
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std::same_as<MoveOnlyView> decltype(auto) v = std::move(sv).base();
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assert(v.mo.get() == 5);
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}
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// LWG 3590 split_view::base() const & is overconstrained
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{
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struct CopyCtorButNotAssignable : std::ranges::view_base {
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int i;
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constexpr CopyCtorButNotAssignable(int ii) : i(ii) {}
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constexpr CopyCtorButNotAssignable(const CopyCtorButNotAssignable&) = default;
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constexpr CopyCtorButNotAssignable(CopyCtorButNotAssignable&&) = default;
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constexpr CopyCtorButNotAssignable& operator=(CopyCtorButNotAssignable&&) = default;
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constexpr CopyCtorButNotAssignable& operator=(const CopyCtorButNotAssignable&) = delete;
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constexpr int* begin() const { return nullptr; }
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constexpr int* end() const { return nullptr; }
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};
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static_assert(std::copy_constructible<CopyCtorButNotAssignable>);
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static_assert(!std::copyable<CopyCtorButNotAssignable>);
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const std::ranges::split_view<CopyCtorButNotAssignable, CopyCtorButNotAssignable> sv{
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CopyCtorButNotAssignable{5}, CopyCtorButNotAssignable{5}};
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std::same_as<CopyCtorButNotAssignable> decltype(auto) v = sv.base();
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assert(v.i == 5);
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}
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return true;
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}
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int main(int, char**) {
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test();
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static_assert(test());
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return 0;
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}
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