NAME¶

iter_swap(std::counted_iterator) - iter_swap(std::counted_iterator)

Synopsis¶

template< std::indirectly_swappable<I> I2 >

friend constexpr void
iter_swap( const counted_iterator& x, const (since C++20)
std::counted_iterator<I2>& y )

noexcept(noexcept(ranges::iter_swap(x.base(),
y.base())));

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.

Parameters¶

x, y - iterator adaptors to the elements to swap

Return value¶

(none)

Complexity¶

Constant.

Example¶

// Run this code

#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

See also¶

swap swaps the values of two objects
(function template)
swap_ranges swaps two ranges of elements
(function template)
iter_swap swaps the elements pointed to by two iterators
(function template)
iter_swap swaps the values referenced by two dereferenceable objects
(C++20) (customization point object)
iter_move casts the result of dereferencing the underlying iterator to its
(C++20) associated rvalue reference type
(function)