C++ Standard Library C++ STL Library

C++ multiset - max_size() Function

The C++ multiset::max_size function returns the maximum size the multiset can reach. The function returns the maximum potential size the multiset can reach due to known system or library implementation limitations.

Note: Multiset is an ordered data container which implies all its elements are ordered all the time.


size_type max_size() const;
size_type max_size() const noexcept;


No parameter is required.

Return Value

Maximum number of elements that can be held in a multiset.

Time Complexity

Constant i.e, Θ(1).


In the example below, the multiset::max_size function is used find out the maximum number of elements that a multiset can hold.

#include <iostream>
#include <set>
using namespace std;
int main (){
  multiset<int> MyMSet{55, 25, 128, 5, 72};
  multiset<int>::iterator it;

  cout<<"The Multiset contains:";
  for(it = MyMSet.begin(); it != MyMSet.end(); ++it)
    cout<<" "<<*it;

  cout<<"\nMultiset size is: "<<MyMSet.size()<<"\n";
  cout<<"Maximum size of the Multiset: "<<MyMSet.max_size()<<"\n"; 
  return 0;

A possible output could be:

The Multiset contains: 5 25 55 72 128
Multiset size is: 5
Maximum size of the Multiset: 230584300921369395

❮ C++ <set> Library