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//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// <iterator>
// reverse_iterator
// pointer operator->() const; // constexpr in C++17
// Be sure to respect LWG 198:
// http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#198
// LWG 198 was superseded by LWG 2360
// http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#2360
#include <iterator>
#include <list>
#include <cassert>
#include "test_macros.h"
#if TEST_STD_VER >= 20
// C++20 bidirectional_iterator that does not satisfy the Cpp17BidirectionalIterator named requirement.
template <class It>
class cpp20_bidirectional_iterator_with_arrow {
It it_;
public:
using iterator_category = std::input_iterator_tag;
using iterator_concept = std::bidirectional_iterator_tag;
using value_type = std::iterator_traits<It>::value_type;
using difference_type = std::iterator_traits<It>::difference_type;
cpp20_bidirectional_iterator_with_arrow() : it_() {}
explicit cpp20_bidirectional_iterator_with_arrow(It it) : it_(it) {}
decltype(auto) operator*() const { return *it_; }
auto operator->() const {
if constexpr (std::is_pointer_v<It>) {
return it_;
} else {
return it_.operator->();
}
}
cpp20_bidirectional_iterator_with_arrow& operator++() {
++it_;
return *this;
}
cpp20_bidirectional_iterator_with_arrow& operator--() {
--it_;
return *this;
}
cpp20_bidirectional_iterator_with_arrow operator++(int) { return cpp20_bidirectional_iterator_with_arrow(it_++); }
cpp20_bidirectional_iterator_with_arrow operator--(int) { return cpp20_bidirectional_iterator_with_arrow(it_--); }
friend bool
operator==(const cpp20_bidirectional_iterator_with_arrow& x, const cpp20_bidirectional_iterator_with_arrow& y) {
return x.it_ == y.it_;
}
friend bool
operator!=(const cpp20_bidirectional_iterator_with_arrow& x, const cpp20_bidirectional_iterator_with_arrow& y) {
return x.it_ != y.it_;
}
friend It base(const cpp20_bidirectional_iterator_with_arrow& i) { return i.it_; }
};
#endif
class A
{
int data_;
public:
A() : data_(1) {}
A(const A&) = default;
A& operator=(const A&) = default;
~A() {data_ = -1;}
int get() const {return data_;}
friend bool operator==(const A& x, const A& y)
{return x.data_ == y.data_;}
};
template <class It>
void
test(It i, typename std::iterator_traits<It>::value_type x)
{
std::reverse_iterator<It> r(i);
assert(r->get() == x.get());
}
class B
{
int data_;
public:
B(int d=1) : data_(d) {}
B(const B&) = default;
B& operator=(const B&) = default;
~B() {data_ = -1;}
int get() const {return data_;}
friend bool operator==(const B& x, const B& y)
{return x.data_ == y.data_;}
const B *operator&() const { return nullptr; }
B *operator&() { return nullptr; }
};
class C
{
int data_;
public:
TEST_CONSTEXPR C() : data_(1) {}
TEST_CONSTEXPR int get() const {return data_;}
friend TEST_CONSTEXPR bool operator==(const C& x, const C& y)
{return x.data_ == y.data_;}
};
TEST_CONSTEXPR C gC;
int main(int, char**)
{
A a;
test(&a+1, A());
{
std::list<B> l;
l.push_back(B(0));
l.push_back(B(1));
l.push_back(B(2));
{
std::list<B>::const_iterator i = l.begin();
assert ( i->get() == 0 ); ++i;
assert ( i->get() == 1 ); ++i;
assert ( i->get() == 2 ); ++i;
assert ( i == l.end ());
}
{
std::list<B>::const_reverse_iterator ri = l.rbegin();
assert ( ri->get() == 2 ); ++ri;
assert ( ri->get() == 1 ); ++ri;
assert ( ri->get() == 0 ); ++ri;
assert ( ri == l.rend ());
}
}
#if TEST_STD_VER > 14
{
typedef std::reverse_iterator<const C *> RI;
constexpr RI it1 = std::make_reverse_iterator(&gC+1);
static_assert(it1->get() == gC.get(), "");
}
#endif
#if TEST_STD_VER >= 20
{
// The underlying iterator models c++20 bidirectional_iterator,
// but does not satisfy c++17 BidirectionalIterator named requirement
B data[] = {1, 2, 3};
cpp20_bidirectional_iterator_with_arrow<B*> iter(data + 3);
auto ri = std::make_reverse_iterator(iter);
assert(ri->get() == 3);
}
#endif
{
((void)gC);
}
return 0;
}
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