unordered_set max_size() in C++ STL

The unordered_set::max_size() is a built-in function in C++ STL, defined in <unordered_set.h> which returns maximum number of elements that an unordered_set container can hold(i.e the maximum size of the unordered_set) due to system constraints or internal implementation . Syntax:

map_name.max_size()

Parameters: This function does not accepts any parameter. It simply returns the maximum size of the container. Return Value: This function returns the maximum number of elements that the unordered_set can hold. Exception: This function does not throw any kind of exception. Below program illustrate the unordered_set::max_size() function in C++: CPP

// C++ program to illustrate the
// unordered_set::max_size function
#include <iostream>
#include <unordered_set>
using namespace std;

int main()
{

    // declaration
    unordered_set<int> sample;

    // Get the maximum size of the unordered_set
    cout << sample.max_size();

    return 0;
}

Output

1152921504606846975

Time Complexity: O(1)