128 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// template<class I2>12// requires assignable_from<I&, const I2&>13// constexpr counted_iterator& operator=(const counted_iterator<I2>& x);14 15#include <iterator>16 17#include "test_macros.h"18#include "test_iterators.h"19 20class AssignableFromIter21{22 int *it_;23 24public:25 typedef std::input_iterator_tag iterator_category;26 typedef int value_type;27 typedef typename std::iterator_traits<int *>::difference_type difference_type;28 typedef int * pointer;29 typedef int & reference;30 31 friend constexpr int *base(const AssignableFromIter& i) {return i.it_;}32 33 AssignableFromIter() = default;34 explicit constexpr AssignableFromIter(int *it) : it_(it) {}35 constexpr AssignableFromIter(const forward_iterator<int*>& it) : it_(base(it)) {}36 37 constexpr AssignableFromIter& operator=(const forward_iterator<int*> &other) {38 it_ = base(other);39 return *this;40 }41 42 constexpr reference operator*() const {return *it_;}43 44 constexpr AssignableFromIter& operator++() {++it_; return *this;}45 constexpr AssignableFromIter operator++(int)46 {AssignableFromIter tmp(*this); ++(*this); return tmp;}47};48 49struct InputOrOutputArchetype {50 using difference_type = int;51 52 int *ptr;53 54 int operator*() { return *ptr; }55 void operator++(int) { ++ptr; }56 InputOrOutputArchetype& operator++() { ++ptr; return *this; }57};58 59constexpr bool test() {60 int buffer[8] = {1, 2, 3, 4, 5, 6, 7, 8};61 62 {63 static_assert( std::is_assignable_v<std::counted_iterator<forward_iterator<int*>>,64 std::counted_iterator<forward_iterator<int*>>>);65 static_assert(!std::is_assignable_v<std::counted_iterator<forward_iterator<int*>>,66 std::counted_iterator<random_access_iterator<int*>>>);67 }68 69 {70 std::counted_iterator iter1(AssignableFromIter{buffer}, 8);71 std::counted_iterator iter2(forward_iterator<int*>{buffer + 2}, 6);72 assert(base(iter1.base()) == buffer);73 assert(iter1.count() == 8);74 std::counted_iterator<AssignableFromIter>& result = (iter1 = iter2);75 assert(&result == &iter1);76 assert(base(iter1.base()) == buffer + 2);77 assert(iter1.count() == 6);78 79 ASSERT_SAME_TYPE(decltype(iter1 = iter2), std::counted_iterator<AssignableFromIter>&);80 }81 {82 std::counted_iterator iter1(AssignableFromIter{buffer}, 8);83 const std::counted_iterator iter2(forward_iterator<int*>{buffer + 2}, 6);84 assert(base(iter1.base()) == buffer);85 assert(iter1.count() == 8);86 std::counted_iterator<AssignableFromIter>& result = (iter1 = iter2);87 assert(&result == &iter1);88 assert(base(iter1.base()) == buffer + 2);89 assert(iter1.count() == 6);90 91 ASSERT_SAME_TYPE(decltype(iter1 = iter2), std::counted_iterator<AssignableFromIter>&);92 }93 94 {95 std::counted_iterator iter1(InputOrOutputArchetype{buffer}, 8);96 std::counted_iterator iter2(InputOrOutputArchetype{buffer + 2}, 6);97 assert(iter1.base().ptr == buffer);98 assert(iter1.count() == 8);99 std::counted_iterator<InputOrOutputArchetype>& result = (iter1 = iter2);100 assert(&result == &iter1);101 assert(iter1.base().ptr == buffer + 2);102 assert(iter1.count() == 6);103 104 ASSERT_SAME_TYPE(decltype(iter1 = iter2), std::counted_iterator<InputOrOutputArchetype>&);105 }106 {107 std::counted_iterator iter1(InputOrOutputArchetype{buffer}, 8);108 const std::counted_iterator iter2(InputOrOutputArchetype{buffer + 2}, 6);109 assert(iter1.base().ptr == buffer);110 assert(iter1.count() == 8);111 std::counted_iterator<InputOrOutputArchetype>& result = (iter1 = iter2);112 assert(&result == &iter1);113 assert(iter1.base().ptr == buffer + 2);114 assert(iter1.count() == 6);115 116 ASSERT_SAME_TYPE(decltype(iter1 = iter2), std::counted_iterator<InputOrOutputArchetype>&);117 }118 119 return true;120}121 122int main(int, char**) {123 test();124 static_assert(test());125 126 return 0;127}128