std::swap(std::multimap)

Since C++17

Header: <map>

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

# Declarations

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)

# Parameters

lhs, rhs: containers whose contents to swap

# Return value

(none)

# 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 << "\nBobby:";
    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 << "\nBobby:";
    std::for_each(bob.begin(), bob.end(), print);
    std::cout << '\n';
}

# See also

swap