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 <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';
}

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)