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std::reverse_iterator::operator*,->(3) C++ Standard Libary std::reverse_iterator::operator*,->(3)

NAME

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

Synopsis


reference operator*() const; (until C++17)
constexpr reference operator*() const; (since C++17)
pointer operator->() const; (until C++17)
constexpr pointer operator->() const; (since C++17)
(until C++20)
constexpr pointer operator->() const (1)
(2)
requires (std::is_pointer_v<Iter> || (since C++20)


requires (const Iter i) {
i.operator->(); });


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


1) Equivalent to Iter tmp = current; return *--tmp;.


2) Equivalent to return std::addressof(operator*());. (until C++20)
2) Equivalent to return current - 1; if Iter is a pointer type. (since C++20)
Otherwise, equivalent to return std::prev(current).operator->();.

Parameters


(none)

Return value


Reference or pointer to the element previous to current.

Example

// Run this code


#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)

See also


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

2024.06.10 http://cppreference.com