std::iter_swap(std::reverse_iterator)

Iterator library

indirectly_readable (C++20)
indirectly_writable (C++20)
weakly_incrementable (C++20)
incrementable (C++20)
is-integer-like is-signed-integer-like (C++20)(C++20)

sentinel_for (C++20)
sized_sentinel_for (C++20)
input_iterator (C++20)
output_iterator (C++20)
input_or_output_iterator (C++20)

forward_iterator (C++20)
bidirectional_iterator (C++20)
random_access_iterator (C++20)
contiguous_iterator (C++20)

Iterator primitives

input_iterator_tagoutput_iterator_tagforward_iterator_tagbidirectional_iterator_tagrandom_access_iterator_tagcontiguous_iterator_tag

(C++20)

iter_value_titer_difference_titer_reference_titer_const_reference_titer_rvalue_reference_titer_common_reference_t

(C++20) (C++20) (C++20) (C++23) (C++20) (C++20)

iterator (deprecated in C++17)
iterator_traits
incrementable_traits (C++20)
indirectly_readable_traits (C++20)

Algorithm concepts and utilities

Indirect callable concepts

indirectly_unary_invocableindirectly_regular_unary_invocable

(C++20)(C++20)

indirect_unary_predicate (C++20)
indirect_binary_predicate (C++20)

indirect_equivalence_relation (C++20)
indirect_strict_weak_order (C++20)

Common algorithm requirements

indirectly_movable (C++20)
indirectly_movable_storable (C++20)
indirectly_copyable (C++20)

indirectly_copyable_storable (C++20)
indirectly_swappable (C++20)
indirectly_comparable (C++20)

permutable (C++20)
mergeable (C++20)
sortable (C++20)

(C++20)

(C++20)

(C++26)

reverse_iterator
make_reverse_iterator (C++14)
move_iterator (C++11)
make_move_iterator (C++11)
default_sentinel_tdefault_sentinel (C++20)(C++20)
unreachable_sentinel_tunreachable_sentinel (C++20)(C++20)

front_insert_iterator
back_insert_iterator
inserter
insert_iterator
front_inserter
back_inserter
move_sentinel (C++20)

common_iterator (C++20)
counted_iterator (C++20)
basic_const_iterator (C++23)
const_iterator (C++23)
const_sentinel (C++23)
make_const_iterator (C++23)
make_const_sentinel (C++23)

Stream iterators

istream_iterator
ostream_iterator

istreambuf_iterator
ostreambuf_iterator

Iterator customization points
ranges::iter_move (C++20)
ranges::iter_swap (C++20)

Iterator operations

advance
distance
prev (C++11)
next (C++11)

ranges::advance (C++20)
ranges::distance (C++20)
ranges::prev (C++20)
ranges::next (C++20)

Range access

begincbegin (C++11)(C++14)
rbegincrbegin (C++14)(C++14)

endcend (C++11)(C++14)
rendcrend (C++14)(C++14)

sizessize (C++17)(C++20)
empty (C++17)
data (C++17)

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.

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>

Parameters

x, y

-

reverse iterators to the elements to swap

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

Run this code

#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

Compiler support
Freestanding and hosted
Language
Standard library
Standard library headers
Named requirements
Feature test macros (C++20)
Language support library
Concepts library (C++20)
Diagnostics library
Memory management library
Metaprogramming library (C++11)
General utilities library
Containers library
Iterators library
Ranges library (C++20)
Algorithms library
Strings library
Text processing library
Numerics library
Date and time library
Input/output library
Filesystem library (C++17)
Concurrency support library (C++11)
Execution support library (C++26)
Technical specifications
Symbols index
External libraries

Member functions
reverse_iterator::reverse_iterator
reverse_iterator::operator=
reverse_iterator::base
reverse_iterator::operator*reverse_iterator::operator->
reverse_iterator::operator[]
reverse_iterator::operator++ reverse_iterator::operator+ reverse_iterator::operator+= reverse_iterator::operator-- reverse_iterator::operator- reverse_iterator::operator-=
Non-member functions
operator==operator!=operator<operator<=operator>operator>=operator<=> (C++20)
operator+
operator-
iter_move (C++20)
iter_swap (C++20)
make_reverse_iterator (C++14)

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 (C++20)	swaps the values referenced by two dereferenceable objects (customization point object)
iter_swap (C++20)	swaps the objects pointed to by two underlying iterators (function template)

std::iter_swap(std::reverse_iterator)

Parameters

Complexity

Exceptions

Example

See also

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