priority_queue::emplace() method

A priority queue is a dynamically resizing container adopter in the C++ Standard Library. Elements in a priority queue are arranged in non-decreasing order such that the first element is always the greatest element in the queue. The priority_queue::emplace() is a method available in the STL which inserts a new element to the priority queue.

Note:
emplace takes the arguments necessary to construct an object in place, whereas push takes a reference to an object.

Syntax:

priorityq_name.emplace(args);

Parameters: The priority_queue::emplace() accepts the element to be inserted into the queue
Return value: none

Example of priority_queue::emplace() method

#include <iostream>
#include <queue>

using namespace std;

void print_q(priority_queue <int> q) //helper function to print the contents of a priority queue
{
    priority_queue <int> temp = q;
    while (!temp.empty())
    {
        cout<<temp.top()<<"\t";
        temp.pop();
    }
    cout<<endl;
}


int main ()
{
    priority_queue<int> q1;

    q1.emplace(10);
    q1.emplace(20);
    q1.emplace(30);
    print_q(q1);

    return 0;
}

Output:

30  20  10