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
3.7 KiB
C++
122 lines
3.7 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, c++20
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// <ranges>
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// Check constraints on the type itself.
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//
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// template <forward_range View, indirect_binary_predicate<iterator_t<View>, iterator_t<View>> Pred>
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// requires view<View> && is_object_v<Pred>
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// class chunk_by_view;
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#include <ranges>
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#include <concepts>
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#include <cstddef>
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#include <iterator>
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#include <type_traits>
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#include "almost_satisfies_types.h"
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#include "test_iterators.h"
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template <class View, class Pred>
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concept CanFormChunkByView = requires { typename std::ranges::chunk_by_view<View, Pred>; };
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// chunk_by_view is not valid when the view is not a forward_range
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namespace test_when_view_is_not_a_forward_range {
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struct View : std::ranges::view_base {
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ForwardIteratorNotDerivedFrom begin() const;
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ForwardIteratorNotDerivedFrom end() const;
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};
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struct Pred {
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bool operator()(int, int) const;
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};
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static_assert(!std::ranges::forward_range<View>);
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static_assert(std::indirect_binary_predicate<Pred, int*, int*>);
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static_assert(std::ranges::view<View>);
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static_assert(std::is_object_v<Pred>);
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static_assert(!CanFormChunkByView<View, Pred>);
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} // namespace test_when_view_is_not_a_forward_range
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// chunk_by_view is not valid when the predicate is not indirect_binary_predicate
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namespace test_when_the_predicate_is_not_indirect_binary_predicate {
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struct View : std::ranges::view_base {
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int* begin() const;
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int* end() const;
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};
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struct Pred {};
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static_assert(std::ranges::forward_range<View>);
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static_assert(!std::indirect_binary_predicate<Pred, int*, int*>);
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static_assert(std::ranges::view<View>);
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static_assert(std::is_object_v<Pred>);
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static_assert(!CanFormChunkByView<View, Pred>);
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} // namespace test_when_the_predicate_is_not_indirect_binary_predicate
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// chunk_by_view is not valid when the view is not a view
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namespace test_when_the_view_param_is_not_a_view {
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struct View {
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int* begin() const;
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int* end() const;
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};
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struct Pred {
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bool operator()(int, int) const;
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};
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static_assert(std::ranges::input_range<View>);
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static_assert(std::indirect_binary_predicate<Pred, int*, int*>);
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static_assert(!std::ranges::view<View>);
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static_assert(std::is_object_v<Pred>);
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static_assert(!CanFormChunkByView<View, Pred>);
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} // namespace test_when_the_view_param_is_not_a_view
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// chunk_by_view is not valid when the predicate is not an object type
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namespace test_when_the_predicate_is_not_an_object_type {
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struct View : std::ranges::view_base {
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int* begin() const;
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int* end() const;
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};
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using Pred = bool (&)(int, int);
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static_assert(std::ranges::input_range<View>);
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static_assert(std::indirect_binary_predicate<Pred, int*, int*>);
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static_assert(std::ranges::view<View>);
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static_assert(!std::is_object_v<Pred>);
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static_assert(!CanFormChunkByView<View, Pred>);
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} // namespace test_when_the_predicate_is_not_an_object_type
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// chunk_by_view is valid when all the constraints are satisfied (test the test)
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namespace test_when_all_the_constraints_are_satisfied {
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struct View : std::ranges::view_base {
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int* begin() const;
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int* end() const;
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};
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struct Pred {
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bool operator()(int, int) const;
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};
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static_assert(std::ranges::input_range<View>);
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static_assert(std::indirect_binary_predicate<Pred, int*, int*>);
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static_assert(std::ranges::view<View>);
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static_assert(std::is_object_v<Pred>);
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static_assert(CanFormChunkByView<View, Pred>);
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} // namespace test_when_all_the_constraints_are_satisfied
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