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

 

C++

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std::priority_queue

Member functions

priority_queue::priority_queue

priority_queue::~priority_queue

priority_queue::operator=

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priority_queue::top

Capacity

priority_queue::empty

priority_queue::size

Modifiers

priority_queue::push

priority_queue::push_range (C++23)

priority_queue::emplace (C++11)

priority_queue::pop

priority_queue::swap (C++11)

Non-member functions

swap(std::priority_queue) (C++11)

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uses_allocator<std::priority_queue> (C++11)

formatter<std::priority_queue> (C++23)

Deduction guides(C++17)

 

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

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