unordered_multimap max_size() function in C++ STL

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

Syntax:

unordered_multimap_name.max_size()

Parameters: The function does not accepts any parameters.

Return Value: It returns an integral values which denotes the maximum size of elements that the container can hold.

Below programs illustrates the above function:

Program 1:

// C++ program to illustrate the
// unordered_multimap::max_size()
#include <bits/stdc++.h>
using namespace std;

int main()
{

    // declaration
    unordered_multimap<int, int> sample1;

    // inserts key and element
    // in sample1
    sample1.insert({ 10, 100 });
    sample1.insert({ 50, 500 });

    cout << "The max number of elements that sample1 can hold: "
         << sample1.size();

    cout << "\nKey and Elements of Sample1 are:";
    for (auto it = sample1.begin(); it != sample1.end(); it++) {
        cout << "{" << it->first << ", " << it->second << "} ";
    }

    return 0;
}

Output:

The max number of elements that sample1 can hold: 2
Key and Elements of Sample1 are:{50, 500} {10, 100}

Program 2:

// C++ program to illustrate the
// unordered_multimap::max_size()
#include <bits/stdc++.h>
using namespace std;

int main()
{

    // declaration
    unordered_multimap<char, char> sample1, sample2;

    // inserts key and element
    // in sample1
    sample1.insert({ 'a', 'A' });
    sample1.insert({ 'g', 'G' });

    cout << "The max number of elements that sample1 can hold: "
         << sample1.size();

    cout << "\nKey and Elements of Sample1 are:";
    for (auto it = sample1.begin(); it != sample1.end(); it++) {
        cout << "{" << it->first << ", " << it->second << "} ";
    }

    return 0;
}

Output:

The max number of elements that sample1 can hold: 2
Key and Elements of Sample1 are:{g, G} {a, A}