set max_size() function in C++ STL

The set::max_size() is a built-in function in C++ STL which returns the maximum number of elements a set container can hold.

Syntax:

set_name.max_size()

Parameters: This function does not accept any parameters.

Return Value: This function returns the maximum number of elements a set container can hold. 

Below program illustrates the above function:  

C++

// CPP program to demonstrate the
// set::max_size() function
#include <bits/stdc++.h>
using namespace std;
int main()
{

    set<int> s1, s2;

    s1.insert(1);

    // If set already contains elements
    cout << s1.max_size() << endl;

    // If set does not have elements
    cout << s2.max_size();

    return 0;
}

Output:

461168601842738790
461168601842738790

Time Complexity: O(1)

Auxiliary Space: O(n)