65 lines · cpp
1//===----------------------------------------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9// UNSUPPORTED: c++03, c++11, c++14, c++1710 11// projected12 13#include <iterator>14 15#include <concepts>16#include <functional>17 18#include "test_iterators.h"19 20using IntPtr = std::projected<int const*, std::identity>;21static_assert(std::same_as<IntPtr::value_type, int>);22static_assert(std::same_as<decltype(*std::declval<IntPtr>()), int const&>);23static_assert(std::same_as<std::iter_difference_t<IntPtr>, std::ptrdiff_t>);24 25struct S { };26 27using Cpp17InputIterator = std::projected<cpp17_input_iterator<S*>, int S::*>;28static_assert(std::same_as<Cpp17InputIterator::value_type, int>);29static_assert(std::same_as<decltype(*std::declval<Cpp17InputIterator>()), int&>);30static_assert(std::same_as<std::iter_difference_t<Cpp17InputIterator>, std::ptrdiff_t>);31 32using Cpp20InputIterator = std::projected<cpp20_input_iterator<S*>, int S::*>;33static_assert(std::same_as<Cpp20InputIterator::value_type, int>);34static_assert(std::same_as<decltype(*std::declval<Cpp20InputIterator>()), int&>);35static_assert(std::same_as<std::iter_difference_t<Cpp20InputIterator>, std::ptrdiff_t>);36 37using ForwardIterator = std::projected<forward_iterator<S*>, int (S::*)()>;38static_assert(std::same_as<ForwardIterator::value_type, int>);39static_assert(std::same_as<decltype(*std::declval<ForwardIterator>()), int>);40static_assert(std::same_as<std::iter_difference_t<ForwardIterator>, std::ptrdiff_t>);41 42using BidirectionalIterator = std::projected<bidirectional_iterator<S*>, S* (S::*)() const>;43static_assert(std::same_as<BidirectionalIterator::value_type, S*>);44static_assert(std::same_as<decltype(*std::declval<BidirectionalIterator>()), S*>);45static_assert(std::same_as<std::iter_difference_t<BidirectionalIterator>, std::ptrdiff_t>);46 47using RandomAccessIterator = std::projected<random_access_iterator<S*>, S && (S::*)()>;48static_assert(std::same_as<RandomAccessIterator::value_type, S>);49static_assert(std::same_as<decltype(*std::declval<RandomAccessIterator>()), S&&>);50static_assert(std::same_as<std::iter_difference_t<RandomAccessIterator>, std::ptrdiff_t>);51 52using ContiguousIterator = std::projected<contiguous_iterator<S*>, S& (S::*)() const>;53static_assert(std::same_as<ContiguousIterator::value_type, S>);54static_assert(std::same_as<decltype(*std::declval<ContiguousIterator>()), S&>);55static_assert(std::same_as<std::iter_difference_t<ContiguousIterator>, std::ptrdiff_t>);56 57template <class I, class F>58constexpr bool projectable = requires {59 typename std::projected<I, F>;60};61 62static_assert(!projectable<int, void (*)(int)>); // int isn't indirectly_readable63static_assert(!projectable<S, void (*)(int)>); // S isn't weakly_incrementable64static_assert(!projectable<int*, void(int)>); // void(int) doesn't satisfy indirectly_regular_unary_invocable65