065dc485bd
This patch implements https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p2443r1.html (`views::chunk_by`). Reviewed By: #libc, var-const Differential Revision: https://reviews.llvm.org/D144767
122 lines
3.5 KiB
C++
122 lines
3.5 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, c++20
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// <ranges>
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// constexpr auto end();
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#include <ranges>
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#include <cassert>
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#include <concepts>
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#include <functional>
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#include "test_iterators.h"
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struct NonCommonRange : std::ranges::view_base {
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using Iterator = forward_iterator<int*>;
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using Sentinel = sentinel_wrapper<Iterator>;
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constexpr explicit NonCommonRange(int* b, int* e) : begin_(b), end_(e) {}
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constexpr Iterator begin() const { return Iterator(begin_); }
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constexpr Sentinel end() const { return Sentinel(Iterator(end_)); }
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private:
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int* begin_;
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int* end_;
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};
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static_assert(std::ranges::forward_range<NonCommonRange>);
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static_assert(!std::ranges::common_range<NonCommonRange>);
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struct CommonRange : std::ranges::view_base {
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using Iterator = bidirectional_iterator<int*>;
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constexpr explicit CommonRange(int* b, int* e) : begin_(b), end_(e) {}
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constexpr Iterator begin() const { return Iterator(begin_); }
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constexpr Iterator end() const { return Iterator(end_); }
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private:
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int* begin_;
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int* end_;
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};
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static_assert(std::ranges::bidirectional_range<CommonRange>);
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static_assert(std::ranges::common_range<CommonRange>);
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constexpr bool test() {
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int buff[] = {1, 0, 3, 1, 2, 3, 4, 5};
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// Check the return type of `end()`
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{
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CommonRange range(buff, buff + 1);
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auto pred = [](int, int) { return true; };
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std::ranges::chunk_by_view view(range, pred);
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using ChunkByView = decltype(view);
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static_assert(std::ranges::common_range<ChunkByView>);
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ASSERT_SAME_TYPE(std::ranges::sentinel_t<ChunkByView>, decltype(view.end()));
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}
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// end() on an empty range
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{
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CommonRange range(buff, buff);
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auto pred = [](int x, int y) { return x <= y; };
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std::ranges::chunk_by_view view(range, pred);
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auto end = view.end();
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assert(end == std::default_sentinel);
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}
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// end() on a 1-element range
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{
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CommonRange range(buff, buff + 1);
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auto pred = [](int& x, int& y) { return x <= y; };
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std::ranges::chunk_by_view view(range, pred);
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auto end = view.end();
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assert(base((*--end).begin()) == buff);
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assert(base((*end).end()) == buff + 1);
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}
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// end() on a 2-element range
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{
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CommonRange range(buff, buff + 2);
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auto pred = [](int const& x, int const& y) { return x <= y; };
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std::ranges::chunk_by_view view(range, pred);
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auto end = view.end();
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assert(base((*--end).begin()) == buff + 1);
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assert(base((*--end).end()) == buff + 1);
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}
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// end() on a 8-element range
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{
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CommonRange range(buff, buff + 8);
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auto pred = [](const int x, const int y) { return x < y; };
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std::ranges::chunk_by_view view(range, pred);
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auto end = view.end();
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assert(base((*--end).end()) == buff + 8);
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assert(base((*--end).end()) == buff + 3);
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}
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// end() on a non-common range
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{
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NonCommonRange range(buff, buff + 1);
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std::ranges::chunk_by_view view(range, std::ranges::less_equal{});
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auto end = view.end();
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ASSERT_SAME_TYPE(std::default_sentinel_t, std::ranges::sentinel_t<decltype(view)>);
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ASSERT_SAME_TYPE(std::default_sentinel_t, decltype(end));
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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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