std::priority_queue<T,Container,Compare>::pop

#include <iostream>
#include <queue>
 
struct Event
{
 int priority{};
 char data{' '};
 
 friend bool operator<(Event const& lhs, Event const& rhs)
 {
 return lhs.priority < rhs.priority;
 }
 
 friend std::ostream & operator<<(std::ostream & os, Event const& e)
 {
 return os << '{' << e.priority << ", '" << e.data << "'}";
 }
};
 
int main()
{
 std::priority_queue <Event> events;
 
 std::cout << "Fill the events queue:\t";
 
 for (auto const e : {Event{6,'L'}, {8,'I'}, {9,'S'}, {1,'T'}, {5,'E'}, {3,'N'}})
 {
 std::cout << e << ' ';
 events.push(e);
 }
 
 std::cout << "\nProcess events:\t\t";
 
 for (; !events.empty(); events.pop())
 {
 Event const& e = events.top();
 std::cout << e << ' ';
 }
 
 std::cout << '\n';
}

Fill the events queue: {6, 'L'} {8, 'I'} {9, 'S'} {1, 'T'} {5, 'E'} {3, 'N'}
Process events: {9, 'S'} {8, 'I'} {6, 'L'} {5, 'E'} {3, 'N'} {1, 'T'}