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-no-concepts 11 // UNSUPPORTED: libcpp-has-no-incomplete-ranges 12 13 // template<range R> 14 // constexpr range_difference_t<R> ranges::distance(R&& r); 15 16 #include <iterator> 17 #include <cassert> 18 #include <ranges> 19 20 #include "test_iterators.h" 21 #include "test_macros.h" 22 23 template<class It, class Sent> 24 constexpr void test_ordinary() { 25 struct R { 26 mutable int a[3] = {1, 2, 3}; 27 constexpr It begin() const { return It(a); } 28 constexpr Sent end() const { return Sent(It(a + 3)); } 29 }; 30 R r; 31 assert(std::ranges::distance(r) == 3); 32 assert(std::ranges::distance(static_cast<R&&>(r)) == 3); 33 assert(std::ranges::distance(static_cast<const R&>(r)) == 3); 34 assert(std::ranges::distance(static_cast<const R&&>(r)) == 3); 35 ASSERT_SAME_TYPE(decltype(std::ranges::distance(r)), std::ranges::range_difference_t<R>); 36 } 37 38 constexpr bool test() { 39 { 40 using R = int[3]; 41 int a[] = {1, 2, 3}; 42 assert(std::ranges::distance(static_cast<R&>(a)) == 3); 43 assert(std::ranges::distance(static_cast<R&&>(a)) == 3); 44 assert(std::ranges::distance(static_cast<const R&>(a)) == 3); 45 assert(std::ranges::distance(static_cast<const R&&>(a)) == 3); 46 ASSERT_SAME_TYPE(decltype(std::ranges::distance(a)), std::ptrdiff_t); 47 ASSERT_SAME_TYPE(decltype(std::ranges::distance(a)), std::ranges::range_difference_t<R>); 48 } 49 { 50 // Unsized range, non-copyable iterator type, rvalue-ref-qualified begin() 51 using It = cpp20_input_iterator<int*>; 52 using Sent = sentinel_wrapper<cpp20_input_iterator<int*>>; 53 using R = std::ranges::subrange<It, Sent, std::ranges::subrange_kind::unsized>; 54 55 int a[] = {1, 2, 3}; 56 auto r = R(It(a), Sent(It(a + 3))); 57 assert(std::ranges::distance(r) == 3); 58 assert(std::ranges::distance(static_cast<R&&>(r)) == 3); 59 static_assert(!std::is_invocable_v<decltype(std::ranges::distance), const R&>); 60 static_assert(!std::is_invocable_v<decltype(std::ranges::distance), const R&&>); 61 } 62 { 63 // Sized range (unsized sentinel type), non-copyable iterator type, rvalue-ref-qualified begin() 64 using It = cpp20_input_iterator<int*>; 65 using Sent = sentinel_wrapper<cpp20_input_iterator<int*>>; 66 using R = std::ranges::subrange<It, Sent, std::ranges::subrange_kind::sized>; 67 68 int a[] = {1, 2, 3}; 69 auto r = R(It(a), Sent(It(a + 3)), 3); 70 assert(std::ranges::distance(r) == 3); 71 assert(std::ranges::distance(static_cast<R&&>(r)) == 3); 72 static_assert(!std::is_invocable_v<decltype(std::ranges::distance), const R&>); 73 static_assert(!std::is_invocable_v<decltype(std::ranges::distance), const R&&>); 74 } 75 { 76 // Sized range (sized sentinel type), non-copyable iterator type 77 test_ordinary<cpp20_input_iterator<int*>, sized_sentinel<cpp20_input_iterator<int*>>>(); 78 } 79 test_ordinary<cpp17_input_iterator<int*>, sentinel_wrapper<cpp17_input_iterator<int*>>>(); 80 test_ordinary<cpp20_input_iterator<int*>, sentinel_wrapper<cpp20_input_iterator<int*>>>(); 81 test_ordinary<output_iterator<int*>, sentinel_wrapper<output_iterator<int*>>>(); 82 test_ordinary<forward_iterator<int*>, sentinel_wrapper<forward_iterator<int*>>>(); 83 test_ordinary<bidirectional_iterator<int*>, sentinel_wrapper<bidirectional_iterator<int*>>>(); 84 test_ordinary<random_access_iterator<int*>, sentinel_wrapper<random_access_iterator<int*>>>(); 85 test_ordinary<contiguous_iterator<int*>, sentinel_wrapper<contiguous_iterator<int*>>>(); 86 test_ordinary<int*, sentinel_wrapper<int*>>(); 87 88 test_ordinary<cpp17_input_iterator<int*>, sized_sentinel<cpp17_input_iterator<int*>>>(); 89 test_ordinary<cpp20_input_iterator<int*>, sized_sentinel<cpp20_input_iterator<int*>>>(); 90 test_ordinary<output_iterator<int*>, sized_sentinel<output_iterator<int*>>>(); 91 test_ordinary<forward_iterator<int*>, sized_sentinel<forward_iterator<int*>>>(); 92 test_ordinary<bidirectional_iterator<int*>, sized_sentinel<bidirectional_iterator<int*>>>(); 93 test_ordinary<random_access_iterator<int*>, sized_sentinel<random_access_iterator<int*>>>(); 94 test_ordinary<contiguous_iterator<int*>, sized_sentinel<contiguous_iterator<int*>>>(); 95 test_ordinary<int*, sized_sentinel<int*>>(); 96 test_ordinary<int*, int*>(); 97 98 // Calling it on a non-range isn't allowed. 99 static_assert(!std::is_invocable_v<decltype(std::ranges::distance), int>); 100 static_assert(!std::is_invocable_v<decltype(std::ranges::distance), int*>); 101 102 return true; 103 } 104 105 int main(int, char**) { 106 test(); 107 static_assert(test()); 108 109 return 0; 110 } 111