Defined in header <algorithm> | (until C++11) | |
---|---|---|
Defined in header <utility> | (since C++11) | |
(1) | ||
template< class T > void swap( T& a, T& b ); | (until C++11) | |
template< class T > void swap( T& a, T& b ) noexcept(/* see below */); | (since C++11) (until C++20) | |
template< class T > constexpr void swap( T& a, T& b ) noexcept(/* see below */); | (since C++20) | |
(2) | ||
template< class T2, std::size_t N > void swap( T2 (&a)[N], T2 (&b)[N]) noexcept(/* see below */); | (since C++11) (until C++20) | |
template< class T2, std::size_t N > constexpr void swap( T2 (&a)[N], T2 (&b)[N]) noexcept(/* see below */); | (since C++20) |
Exchanges the given values.
a
and b
. This overload does not participate in overload resolution unless std::is_move_constructible_v<T> && std::is_move_assignable_v<T>
is true
. (since C++17)
a
and b
. In effect calls std::swap_ranges(a, a+N, b)
. This overload does not participate in overload resolution unless std::is_swappable_v<T2>
is true
. (since C++17)
a, b | - | the values to be swapped |
Type requirements | ||
-T must meet the requirements of MoveAssignable and MoveConstructible. |
||
-T2 must meet the requirements of Swappable. |
(none).
(none). | (until C++11) |
noexcept specification: noexcept( | (since C++11) |
noexcept specification: noexcept(noexcept(swap(*a, *b))) swap in the exception specification finds this function template in addition to anything found by the usual lookup rules, making the exception specification equivalent to C++17 std::is_nothrow_swappable . | (until C++17) |
noexcept specification: noexcept(std::is_nothrow_swappable_v<T2>) | (since C++17) |
| (until C++20) |
The expected way to make a program-defined type swappable is to provide a non-member function swap in the same namespace as the type: see Swappable for details.
The following overloads are already provided by the standard library:
(C++11) | specializes the std::swap algorithm (function template) |
(C++11) | specializes the std::swap algorithm (function template) |
(C++11) | specializes the std::swap algorithm (function template) |
(C++11) | specializes the std::swap algorithm (function template) |
(C++11) | specializes the std::swap algorithm (function template) |
(C++11) | specializes the std::swap algorithm (function template) |
specializes the std::swap algorithm (function template) |
|
(C++11) | specializes the std::swap algorithm (function template) |
specializes the std::swap algorithm (function template) |
|
(C++11) | specializes the std::swap algorithm (function template) |
specializes the std::swap algorithm (function template) |
|
specializes the std::swap algorithm (function template) |
|
specializes the std::swap algorithm (function template) |
|
specializes the std::swap algorithm (function template) |
|
specializes the std::swap algorithm (function template) |
|
specializes the std::swap algorithm (function template) |
|
(C++11) | specializes the std::swap algorithm (function template) |
(C++11) | specializes the std::swap algorithm (function template) |
(C++11) | specializes the std::swap algorithm (function template) |
(C++11) | specializes the std::swap algorithm (function template) |
specializes the std::swap algorithm (function template) |
|
specializes the std::swap algorithm (function template) |
|
specializes the std::swap algorithm (function template) |
|
(C++11) | specializes the std::swap() algorithm (function template) |
(C++11) | specializes the std::swap algorithm (function template) |
(C++11) | specializes the std::swap algorithm (function template) |
(C++11) | specializes the std::swap algorithm (function template) |
(C++11) | specializes the std::swap algorithm (function template) |
(C++11) | specializes the std::swap algorithm (function template) |
(C++11) | specializes the std::swap algorithm (function template) |
(C++11) | specializes the std::swap algorithm (function template) |
(C++11) | specializes the std::swap algorithm (function template) |
(C++20) | specializes the std::swap algorithm (function template) |
(C++11) | specializes the std::swap algorithm (function template) |
(C++11) | specializes the std::swap() algorithm (function template) |
(C++11) | specializes the std::swap algorithm (function template) |
(C++11) | specialization of std::swap for unique_lock (function template) |
(C++11) | specializes the std::swap algorithm (function template) |
(C++11) | specializes the std::swap algorithm (function template) |
(C++17) | specializes the std::swap algorithm (function) |
(C++17) | specializes the std::swap algorithm (function) |
(C++17) | specializes the std::swap algorithm (function) |
swaps two paths (function) |
#include <algorithm> #include <iostream> int main() { int a = 5, b = 3; // before std::cout << a << ' ' << b << '\n'; std::swap(a,b); // after std::cout << a << ' ' << b << '\n'; }
Output:
5 3 3 5
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
DR | Applied to | Behavior as published | Correct behavior |
---|---|---|---|
LWG 2554 | C++11 | swapping multi-dimensional arrays can never be noexcept due to name lookup problems | made to work |
swaps the elements pointed to by two iterators (function template) |
|
swaps two ranges of elements (function template) |
|
(C++14) | replaces the argument with a new value and returns its previous value (function template) |
© cppreference.com
Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.
http://en.cppreference.com/w/cpp/algorithm/swap