NAME¶

std::priority_queue::pop - std::priority_queue::pop

Synopsis¶

void pop();

Removes the top element from the priority queue. Effectively calls
std::pop_heap(c.begin(), c.end(), comp); c.pop_back();

Parameters¶

(none)

Return value¶

(none)

Complexity¶

Logarithmic number of comparisons plus the complexity of Container::pop_back.

Example¶

// Run this code

#include <queue>
#include <iostream>

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:\n";

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 << "\n" "Process events:\n";

for (; !events.empty(); events.pop()) {
Event const& e = events.top();
std::cout << e << ' ';
}
}

Output:¶

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' }

See also¶

emplace constructs element in-place and sorts the underlying container
(C++11) (public member function)
push inserts element and sorts the underlying container
(public member function)
top accesses the top element
(public member function)