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-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 // UNSUPPORTED: c++03, c++11, c++14, c++17 10 // UNSUPPORTED: libcpp-has-no-incomplete-ranges 11 12 // constexpr auto begin() requires (!simple-view<V>); 13 // constexpr auto begin() const requires range<const V>; 14 15 #include <ranges> 16 #include <cassert> 17 18 #include "test_macros.h" 19 #include "test_iterators.h" 20 #include "test_range.h" 21 #include "types.h" 22 23 struct NonCommonSimpleView : std::ranges::view_base { 24 int* begin() const; 25 sentinel_wrapper<int*> end() const; 26 size_t size() { return 0; } // deliberately non-const 27 }; 28 static_assert(std::ranges::sized_range<NonCommonSimpleView>); 29 static_assert(!std::ranges::sized_range<const NonCommonSimpleView>); 30 31 constexpr bool test() { 32 int buffer[8] = {1, 2, 3, 4, 5, 6, 7, 8}; 33 34 // sized_range && random_access_iterator 35 { 36 std::ranges::take_view<SizedRandomAccessView> tv(SizedRandomAccessView(buffer), 4); 37 assert(tv.begin() == SizedRandomAccessView(buffer).begin()); 38 ASSERT_SAME_TYPE(decltype(tv.begin()), RandomAccessIter); 39 } 40 41 { 42 const std::ranges::take_view<SizedRandomAccessView> tv(SizedRandomAccessView(buffer), 4); 43 assert(tv.begin() == SizedRandomAccessView(buffer).begin()); 44 ASSERT_SAME_TYPE(decltype(tv.begin()), RandomAccessIter); 45 } 46 47 // sized_range && !random_access_iterator 48 { 49 std::ranges::take_view<SizedForwardView> tv(SizedForwardView{buffer}, 4); 50 assert(tv.begin() == std::counted_iterator<ForwardIter>(ForwardIter(buffer), 4)); 51 ASSERT_SAME_TYPE(decltype(tv.begin()), std::counted_iterator<ForwardIter>); 52 } 53 54 { 55 const std::ranges::take_view<SizedForwardView> tv(SizedForwardView{buffer}, 4); 56 assert(tv.begin() == std::counted_iterator<ForwardIter>(ForwardIter(buffer), 4)); 57 ASSERT_SAME_TYPE(decltype(tv.begin()), std::counted_iterator<ForwardIter>); 58 } 59 60 // !sized_range 61 { 62 std::ranges::take_view<MoveOnlyView> tv(MoveOnlyView{buffer}, 4); 63 assert(tv.begin() == std::counted_iterator<int*>(buffer, 4)); 64 ASSERT_SAME_TYPE(decltype(tv.begin()), std::counted_iterator<int*>); 65 } 66 67 { 68 const std::ranges::take_view<MoveOnlyView> tv(MoveOnlyView{buffer}, 4); 69 assert(tv.begin() == std::counted_iterator<int*>(buffer, 4)); 70 ASSERT_SAME_TYPE(decltype(tv.begin()), std::counted_iterator<int*>); 71 } 72 73 // __simple_view<V> && sized_range<V> && !size_range<!V> 74 { 75 std::ranges::take_view<NonCommonSimpleView> tv{}; 76 ASSERT_SAME_TYPE(decltype(tv.begin()), std::counted_iterator<int*>); 77 ASSERT_SAME_TYPE(decltype(std::as_const(tv).begin()), std::counted_iterator<int*>); 78 } 79 80 return true; 81 } 82 83 int main(int, char**) { 84 test(); 85 static_assert(test()); 86 87 return 0; 88 } 89