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std::swap(std::array)

From cppreference.com
< cpp‎ | container‎ | array
Defined in header <array>
template< class T, std::size_t N >

void swap( std::array<T,N>& lhs,

           std::array<T,N>& rhs );
(since C++11)
(until C++17)
template< class T, std::size_t N >

void swap( std::array<T,N>& lhs,

           std::array<T,N>& rhs ) noexcept(/* see below */);
(since C++17)
(until C++20)
template< class T, std::size_t N >

constexpr void swap( std::array<T,N>& lhs,

                     std::array<T,N>& rhs ) noexcept(/* see below */);
(since C++20)

Specializes the std::swap algorithm for std::array. Swaps the contents of lhs and rhs. Calls lhs.swap(rhs).

This overload only participates in overload resolution if N == 0 or std::is_swappable<T>::value is true.

(since C++17)

Contents

[edit] Parameters

lhs, rhs - containers whose contents to swap

[edit] Return value

(none)

[edit] Complexity

Linear in size of the container.

[edit] Exceptions

noexcept specification:  
noexcept(noexcept(lhs.swap(rhs)))
(since C++17)


[edit] Example

#include <algorithm>
#include <iostream>
#include <array>
 
int main()
{
    std::array<int, 3> alice{1, 2, 3};
    std::array<int, 3> bob{7, 8, 9};
 
    auto print = [](const int& n) { std::cout << ' ' << n; };
 
    // Print state before swap
    std::cout << "alice:";
    std::for_each(alice.begin(), alice.end(), print);
    std::cout << "\n" "bob  :";
    std::for_each(bob.begin(), bob.end(), print);
    std::cout << '\n';
 
    std::cout << "-- SWAP\n";
    std::swap(alice, bob);
 
    // Print state after swap
    std::cout << "alice:";
    std::for_each(alice.begin(), alice.end(), print);
    std::cout << "\n" "bob  :";
    std::for_each(bob.begin(), bob.end(), print);
    std::cout << '\n';
}

Output:

alice: 1 2 3
bob  : 7 8 9
-- SWAP
alice: 7 8 9
bob  : 1 2 3

[edit] See also

swaps the contents
(public member function) [edit]