std::counted_iterator<I>::operator[]
constexpr decltype(auto) operator[]( std::iter_difference_t<I> n ) const
requires std::random_access_iterator<I>; |
(since C++20) |
Accesses the element at specified relative location. The behavior is undefined if n is not less than the recorded distance to the end.
Parameters
| n | - | position relative to current location |
Return value
this->base()[n].
Example
#include <iostream>
#include <iterator>
#include <array>
#include <list>
int main()
{
std::array array{'A', 'B', 'C', 'D', 'E'};
std::counted_iterator it{ array.begin() + 1, /*count:*/ 3 };
for (int i{}; i != it.count(); ++i)
std::cout << it[i] << ' ';
std::cout << '\n';
for (int i{}; i != it.count(); ++i)
it[i] += ('E' - 'A');
for (int i{}; i != it.count(); ++i)
std::cout << it[i] << ' ';
std::cout << '\n';
std::list list {'X', 'Y', 'Z', 'W'};
std::counted_iterator it2{ list.begin(), 3 };
// char x = it2[0]; // Error: requirement `random_access_iterator` was not satisfied.
std::cout << *it2 << '\n'; // OK
}
Output:
B C D F G H X
See also
|
(C++20)
|
accesses the pointed-to element (public member function) |
© cppreference.com
Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.
https://en.cppreference.com/w/cpp/iterator/counted_iterator/operator_at
