C++ multiset - swap() Function

The C++ multiset::swap function is used to exchange all elements of one multiset with all elements of another multiset. To apply this function, the data-type of both multisets must be same, although the size may differ.

Syntax

C++98
C++11

void swap (multiset& other);

void swap (multiset& other);

Parameters

other Specify multiset, whose elements need to be exchanged with another multiset.

Return Value

None.

Time Complexity

Constant i.e, Θ(1)

Example:

In the example below, the multiset::swap function is used to exchange all elements of multiset MyMSet1 with all elements of multiset MyMSet2.

#include <iostream>
#include <set>
using namespace std;
 
int main (){
  multiset<int> MyMSet1{10, 20, 30, 40, 50};
  multiset<int> MyMSet2{5, 55, 555};

  multiset<int>::iterator it;

  cout<<"Before Swapping, The MyMSet1 contains:";
  for(it = MyMSet1.begin(); it != MyMSet1.end(); ++it)
    cout<<" "<<*it;
  cout<<"\nBefore Swapping, The MyMSet2 contains:";
  for(it = MyMSet2.begin(); it != MyMSet2.end(); ++it)
    cout<<" "<<*it;

  MyMSet1.swap(MyMSet2);

  cout<<"\n\nAfter Swapping, The MyMSet1 contains:";
  for(it = MyMSet1.begin(); it != MyMSet1.end(); ++it)
    cout<<" "<<*it;
  cout<<"\nAfter Swapping, The MyMSet2 contains:";
  for(it = MyMSet2.begin(); it != MyMSet2.end(); ++it)
    cout<<" "<<*it;

  return 0;
}

The output of the above code will be:

Before Swapping, The MyMSet1 contains: 10 20 30 40 50
Before Swapping, The MyMSet2 contains: 5 55 555

After Swapping, The MyMSet1 contains: 5 55 555
After Swapping, The MyMSet2 contains: 10 20 30 40 50

❮ C++ <set> Library