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 // template<range R> 13 // constexpr range_difference_t<R> ranges::distance(R&& r); 14 15 #include <iterator> 16 #include <cassert> 17 #include <ranges> 18 19 #include "test_iterators.h" 20 #include "test_macros.h" 21 22 template<class It, class Sent> 23 constexpr void test_ordinary() { 24 struct R { 25 mutable int a[3] = {1, 2, 3}; 26 constexpr It begin() const { return It(a); } 27 constexpr Sent end() const { return Sent(It(a + 3)); } 28 }; 29 R r; 30 assert(std::ranges::distance(r) == 3); 31 assert(std::ranges::distance(static_cast<R&&>(r)) == 3); 32 assert(std::ranges::distance(static_cast<const R&>(r)) == 3); 33 assert(std::ranges::distance(static_cast<const R&&>(r)) == 3); 34 ASSERT_SAME_TYPE(decltype(std::ranges::distance(r)), std::ranges::range_difference_t<R>); 35 } 36 37 constexpr bool test() { 38 { 39 using R = int[3]; 40 int a[] = {1, 2, 3}; 41 assert(std::ranges::distance(static_cast<R&>(a)) == 3); 42 assert(std::ranges::distance(static_cast<R&&>(a)) == 3); 43 assert(std::ranges::distance(static_cast<const R&>(a)) == 3); 44 assert(std::ranges::distance(static_cast<const R&&>(a)) == 3); 45 ASSERT_SAME_TYPE(decltype(std::ranges::distance(a)), std::ptrdiff_t); 46 ASSERT_SAME_TYPE(decltype(std::ranges::distance(a)), std::ranges::range_difference_t<R>); 47 } 48 { 49 // Unsized range, non-copyable iterator type, rvalue-ref-qualified begin() 50 using It = cpp20_input_iterator<int*>; 51 using Sent = sentinel_wrapper<cpp20_input_iterator<int*>>; 52 using R = std::ranges::subrange<It, Sent, std::ranges::subrange_kind::unsized>; 53 54 int a[] = {1, 2, 3}; 55 auto r = R(It(a), Sent(It(a + 3))); 56 assert(std::ranges::distance(r) == 3); 57 assert(std::ranges::distance(static_cast<R&&>(r)) == 3); 58 static_assert(!std::is_invocable_v<decltype(std::ranges::distance), const R&>); 59 static_assert(!std::is_invocable_v<decltype(std::ranges::distance), const R&&>); 60 } 61 { 62 // Sized range (unsized sentinel type), non-copyable iterator type, rvalue-ref-qualified begin() 63 using It = cpp20_input_iterator<int*>; 64 using Sent = sentinel_wrapper<cpp20_input_iterator<int*>>; 65 using R = std::ranges::subrange<It, Sent, std::ranges::subrange_kind::sized>; 66 67 int a[] = {1, 2, 3}; 68 auto r = R(It(a), Sent(It(a + 3)), 3); 69 assert(std::ranges::distance(r) == 3); 70 assert(std::ranges::distance(static_cast<R&&>(r)) == 3); 71 static_assert(!std::is_invocable_v<decltype(std::ranges::distance), const R&>); 72 static_assert(!std::is_invocable_v<decltype(std::ranges::distance), const R&&>); 73 } 74 { 75 // Sized range (sized sentinel type), non-copyable iterator type 76 test_ordinary<cpp20_input_iterator<int*>, sized_sentinel<cpp20_input_iterator<int*>>>(); 77 } 78 test_ordinary<cpp17_input_iterator<int*>, sentinel_wrapper<cpp17_input_iterator<int*>>>(); 79 test_ordinary<cpp20_input_iterator<int*>, sentinel_wrapper<cpp20_input_iterator<int*>>>(); 80 test_ordinary<cpp17_output_iterator<int*>, sentinel_wrapper<cpp17_output_iterator<int*>>>(); 81 test_ordinary<forward_iterator<int*>, sentinel_wrapper<forward_iterator<int*>>>(); 82 test_ordinary<bidirectional_iterator<int*>, sentinel_wrapper<bidirectional_iterator<int*>>>(); 83 test_ordinary<random_access_iterator<int*>, sentinel_wrapper<random_access_iterator<int*>>>(); 84 test_ordinary<contiguous_iterator<int*>, sentinel_wrapper<contiguous_iterator<int*>>>(); 85 test_ordinary<int*, sentinel_wrapper<int*>>(); 86 87 test_ordinary<cpp17_input_iterator<int*>, sized_sentinel<cpp17_input_iterator<int*>>>(); 88 test_ordinary<cpp20_input_iterator<int*>, sized_sentinel<cpp20_input_iterator<int*>>>(); 89 test_ordinary<cpp17_output_iterator<int*>, sized_sentinel<cpp17_output_iterator<int*>>>(); 90 test_ordinary<forward_iterator<int*>, sized_sentinel<forward_iterator<int*>>>(); 91 test_ordinary<bidirectional_iterator<int*>, sized_sentinel<bidirectional_iterator<int*>>>(); 92 test_ordinary<random_access_iterator<int*>, sized_sentinel<random_access_iterator<int*>>>(); 93 test_ordinary<contiguous_iterator<int*>, sized_sentinel<contiguous_iterator<int*>>>(); 94 test_ordinary<int*, sized_sentinel<int*>>(); 95 test_ordinary<int*, int*>(); 96 97 // Calling it on a non-range isn't allowed. 98 static_assert(!std::is_invocable_v<decltype(std::ranges::distance), int>); 99 static_assert(!std::is_invocable_v<decltype(std::ranges::distance), int*>); 100 101 return true; 102 } 103 104 int main(int, char**) { 105 test(); 106 static_assert(test()); 107 108 return 0; 109 } 110