std::pair::swap

 

C++

Language

Standard library headers

Concepts

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Filesystem library (C++17)

Technical Specifications

 

Utilities library

Type support (basic types, RTTI, type traits)

Dynamic memory management

Error handling

Program utilities

Variadic functions

Date and time

Function objects

initializer_list (C++11)

bitset

hash (C++11)

Relational operators

rel_ops::operator!=rel_ops::operator>rel_ops::operator<=rel_ops::operator>=

Optional and any

optional (C++17)

any (C++17)

Pairs and tuples

pair

tuple (C++11)

apply (C++17)

piecewise_construct_t (C++11)

piecewise_construct (C++11)

integer_sequence (C++14)

Swap, forward and move

swap

exchange (C++14)

forward (C++11)

move (C++11)

move_if_noexcept (C++11)

Type operations

declval (C++11)

as_const (C++17)

 

std::pair

Member functions

pair::pair

pair::operator=

pair::swap

Non-member functions

make_pair

operator==operator!=operator<operator<=operator>operator>=

std::swap

get (C++11)

Helper classes

tuple_size (C++11)

tuple_element (C++11)

 

void swap(pair& other);		(since C++11)

Swaps first with other.first and second with other.second.

This function does not participate in overload resolution unless std::is_swappable_v<first_type> && std::is_swappable_v<second_type>

(since C++17)

Parameters

other

-

pair of values to swap

Return value

(none)

Example

Run this code

#include <iostream>
#include <utility>
#include <string>
int main()
{
    std::pair<int, std::string> p1, p2;
    p1 = std::make_pair(10, "test");
    p2.swap(p1);
    std::cout << "(" << p2.first << ", " << p2.second << ")\n";
}

Output:

(10, test)

See also

noexcept specification:   noexcept(      noexcept(std::swap(first, other.first)) &&      noexcept(std::swap(second, other.second)) )	(until C++17)
noexcept specification:   noexcept(      std::is_nothrow_swappable<first_type>::value) &&      std::is_nothrow_swappable<second_type>::value) )	(since C++17)

swap	swaps the values of two objects (function template)