template< std::indirectly_swappable<I> I2 >
friend constexpr void
iter_swap( const counted_iterator& x, const std::counted_iterator<I2>& y )
noexcept(noexcept(ranges::iter_swap(x.base(), y.base())));
| (since C++20) |
Swaps the objects pointed to by two underlying iterators. The behavior is undefined if either x.count() or y.count() is equal to 0.
The function body is equivalent to: ranges::iter_swap(x.base(), y.base());.
This function template is not visible to ordinary unqualified or qualified lookup, and can only be found by argument-dependent lookup when std::counted_iterator<I> is an associated class of the arguments.
| x, y | - | iterator adaptors to the elements to swap |
(none).
Constant.
#include <iostream>
#include <iterator>
#include <list>
#include <vector>
int main()
{
std::vector p { 1, 2, 3, 4 },
q { 5, 6, 7, 8 };
std::counted_iterator<std::vector<int>::iterator> ip { p.begin(), 2 };
std::counted_iterator<std::vector<int>::iterator> iq { q.begin(), 3 };
std::cout << *ip << ' ' << *iq << '\n';
iter_swap(ip, iq); // ADL
std::cout << *ip << ' ' << *iq << '\n';
std::list x {0, 1, 3};
std::counted_iterator<std::list<int>::iterator> ix { x.begin(), 2 };
// iter_swap(ip, ix); // error: not indirectly swappable
}Output:
1 5 5 1
| swaps the values of two objects (function template) |
|
| swaps two ranges of elements (function template) |
|
| swaps the elements pointed to by two iterators (function template) |
|
|
(C++20) | swaps the values referenced by two dereferenceable objects (customization point object) |
|
(C++20) | casts the result of dereferencing the underlying iterator to its associated rvalue reference type (function) |
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