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std::swap(std::multimap)

From cppreference.com
< cpp‎ | container‎ | multimap
 
 
Containers library
Sequence
(C++11)
Associative
Unordered associative
Adaptors
Views
(C++20)
 
 
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.

[edit] 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]