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std::reverse_iterator<Iter>::operator*,->

From cppreference.com
 
 
Iterator library
Iterator concepts
Iterator primitives
Algorithm concepts and utilities
Indirect callable concepts
Common algorithm requirements
(C++20)
(C++20)
(C++20)
Utilities
(C++20)
Iterator adaptors
Range access
(C++11)(C++14)
(C++14)(C++14)  
(C++11)(C++14)
(C++14)(C++14)  
(C++17)(C++20)
(C++17)
(C++17)
 
 
reference operator*() const;
(1) (constexpr since C++17)
(2)
pointer operator->() const;
(constexpr since C++17)
(until C++20)
constexpr pointer operator->() const

    requires (std::is_pointer_v<Iter> ||

              requires (const Iter i) { i.operator->(); });
(since C++20)

Returns a reference or pointer to the element previous to current.

 Member function  Equivalent to
operator* Iter tmp = current; return *--tmp;
operator->

return &(operator*());

(until C++11)

return std::addressof(operator*());

(since C++11)
(until C++20)
(since C++20)

Contents

[edit] Return value

As described above.

[edit] Example

#include <complex>
#include <iostream>
#include <iterator>
#include <vector>
 
int main()
{
    using RI0 = std::reverse_iterator<int*>;
    int a[]{0, 1, 2, 3};
    RI0 r0{std::rbegin(a)};
    std::cout << "*r0 = " << *r0 << '\n';
    *r0 = 42;
    std::cout << "a[3] = " << a[3] << '\n';
 
    using RI1 = std::reverse_iterator<std::vector<int>::iterator>;
    std::vector<int> vi{0, 1, 2, 3};
    RI1 r1{vi.rend() - 2};
    std::cout << "*r1 = " << *r1 << '\n';
 
    using RI2 = std::reverse_iterator<std::vector<std::complex<double>>::iterator>;
    std::vector<std::complex<double>> vc{{1, 2}, {3, 4}, {5, 6}, {7, 8}};
    RI2 r2{vc.rbegin() + 1};
    std::cout << "vc[2] = (" << r2->real() << ',' << r2->imag() << ")\n";
}

Output:

*r0 = 3
a[3] = 42
*r1 = 1
vc[2] = (5,6)

[edit] Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR Applied to Behavior as published Correct behavior
LWG 2188 C++11 operator-> used & to take address uses std::addressof instead

[edit] See also

accesses an element by index
(public member function) [edit]