std::iter_swap(std::reverse_iterator)
template< std::indirectly_swappable<Iter> Iter2 >
friend constexpr void
iter_swap( const reverse_iterator& x,
const std::reverse_iterator<Iter2>& y ) noexcept(/*see below*/); |
(since C++20) |
Swaps the objects pointed to by two adjusted underlying iterators. The function body is equivalent to:
auto tmp_x = x.base(); auto tmp_y = y.base(); ranges::iter_swap(--tmp_x, --tmp_y);
This function template is not visible to ordinary unqualified or qualified lookup, and can only be found by argument-dependent lookup when std::reverse_iterator<Iter> is an associated class of the arguments.
Parameters
| x, y | - | reverse iterators to the elements to swap |
Return value
(none).
Complexity
Constant.
Exceptions
noexcept specification:
noexcept(
std::is_nothrow_copy_constructible_v<Iter> &&
std::is_nothrow_copy_constructible_v<Iter2> &&
noexcept(ranges::iter_swap(--std::declval<Iter&>(), --std::declval<Iter2&>()))
.
)
Example
#include <iostream>
#include <iterator>
#include <list>
#include <vector>
int main()
{
std::vector v {1, 2, 3};
std::list l {4, 5, 6};
std::reverse_iterator<std::vector<int>::iterator> r1 { v.rbegin() };
std::reverse_iterator<std::list<int>::iterator> r2 { l.rbegin() };
std::cout << *r1 << ' ' << *r2 << '\n';
iter_swap(r1, r2); // ADL
std::cout << *r1 << ' ' << *r2 << '\n';
}
Output:
3 6 6 3
See also
| 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)
|
swaps the objects pointed to by two underlying iterators (function template) |
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