std::ranges::iter_swap

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Iterator library

Iterator concepts

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)

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Defined in header`<iterator>`
namespace ranges{ inlinenamespace/* unspecified /{ inlineconstexpr/ unspecified / iter_swap=/ unspecified */; } }		(since C++20) (customization point object)
Call signature
template<class I1,class I2> constexprvoid iter_swap( I1&& i1, I2&& i2)noexcept(/* see below */);		(since C++20)
Helper function
template<class X,class Y> constexprstd::iter_value_t<X> iter-exchange-move( X&& x, Y&& y) noexcept(noexcept(std::iter_value_t<X>(std::ranges::iter_move(x)))&& noexcept(*x= std::ranges::iter_move(y)));		(exposition only*)

Swaps values denoted by two iterators.

The effect of the exposition-only helper functioniter-exchange-move is equivalent to

std::iter_value_t<X> old(std::ranges::iter_move(x));*x= std::ranges::iter_move(y);return old;

ranges::iter_swap(i1, i2) isexpression-equivalent to:

(void)iter_swap(i1, i2), ifi1 ori2 has a class or enumeration type and the expression is well-formed, where theoverload resolution ofiter_swap is performed with the additional candidatevoid iter_swap(auto,auto)= delete;^[1], excludingstd::ranges::iter_swap itself.
- If the selected overload does not exchange the value denoted byi1 andi2, the program is ill-formed, no diagnostic required.
Otherwise,ranges::swap(*i1,*i2) if bothI1 andI2 modelindirectly_readable and ifstd::iter_reference_t<I1> andstd::iter_reference_t<I2> modelswappable_with.
Otherwise,(void)(*i1= iter-exchange-move(i2, i1)), ifstd::indirectly_movable_storable<I1, I2> andstd::indirectly_movable_storable<I2, I1> are both modeled, except thati1 is only evaluated once.
Otherwise,ranges::iter_swap(i1, i2) is ill-formed, which can result insubstitution failure whenranges::iter_swap(i1, i2) appears in the immediate context of a template instantiation.

↑This precludes calling unconstrainedstd::iter_swap.

Customization point objects

The nameranges::iter_swap denotes acustomization point object, which is a constfunction object of aliteral semiregular class type. SeeCustomizationPointObject for details.

[edit]Example

This section is incomplete
Reason: no example

[edit]See also

iter_swap (C++20)	swaps the objects pointed to by two adjusted underlying iterators (function template)[edit]
iter_swap (C++20)	swaps the objects pointed to by two underlying iterators (function template)[edit]
iter_swap	swaps the elements pointed to by two iterators (function template)[edit]