C++ set - max_size() Function

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

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

Syntax

• C++98
• C++11

size_type max_size() const;

size_type max_size() const noexcept;

Parameters

No parameter is required.

Return Value

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

Time Complexity

Constant i.e, Θ(1).

Example:

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

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

  cout<<"The Set contains:";
  for(it = MySet.begin(); it != MySet.end(); ++it)
    cout<<" "<<*it;
    
  cout<<"\nSet size is: "<<MySet.size()<<"\n";
  cout<<"Maximum size of the Set: "<<MySet.max_size()<<"\n"; 
  
  return 0;
}

A possible output could be:

The Set contains: 5 25 55 72 128
Set size is: 5
Maximum size of the Set: 461168601842738790