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std::swap(std::multimap)

From cppreference.com
< cpp‎ | container‎ | multimap
 
 
 
 
Defined in header <map>
template< class Key, class T, class Compare, class Alloc >

void swap( std::multimap<Key, T, Compare, Alloc>& lhs,

           std::multimap<Key, T, Compare, Alloc>& rhs );
(until C++17)
template< class Key, class T, class Compare, class Alloc >

void swap( std::multimap<Key, T, Compare, Alloc>& lhs,
           std::multimap<Key, T, Compare, Alloc>& rhs )

               noexcept(/* see below */);
(since C++17)

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

Contents

[edit] Parameters

lhs, rhs - containers whose contents to swap

[edit] Return value

(none)

[edit] Complexity

Constant.

Exceptions

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

[edit] Example

#include <algorithm>
#include <iostream>
#include <map>
 
int main()
{
    std::multimap<int, char> alice{{1, 'a'}, {2, 'b'}, {3, 'c'}};
    std::multimap<int, char> bob{{7, 'Z'}, {8, 'Y'}, {9, 'X'}, {10, 'W'}};
 
    auto print = [](std::pair<const int, char>& n)
    {
        std::cout << ' ' << n.first << ':' << n.second;
    };
 
    // 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:a 2:b 3:c
Bob  : 7:Z 8:Y 9:X 10:W
-- SWAP
Alice: 7:Z 8:Y 9:X 10:W
Bob  : 1:a 2:b 3:c

[edit] See also

swaps the contents
(public member function) [edit]