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

From cppreference.com
 
 
 
 
bool empty() const;
(until C++20)
[[nodiscard]] bool empty() const;
(since C++20)

Checks if the underlying container has no elements. Equivalent to return c.empty();.

Contents

[edit] Parameters

(none)

[edit] Return value

true if the underlying container is empty, false otherwise.

[edit] Complexity

Constant.

[edit] Example

#include <algorithm>
#include <iostream>
#include <queue>
 
int main()
{
    std::cout << std::boolalpha;
 
    std::priority_queue<int> queue;
 
    std::cout << "Initially, queue.empty(): " << queue.empty() << '\n';
 
    queue.push(42);
    std::cout << "After adding elements, queue.empty(): " << queue.empty() << '\n';
}

Output:

Initially, queue.empty(): true
After adding elements, queue.empty(): false

[edit] See also

returns the number of elements
(public member function) [edit]
(C++17)
checks whether the container is empty
(function template) [edit]