public member function
<queue>
Test whether container is empty
Returns whether the priority_queue is empty: i.e. whether its size is zero.
This member function effectively calls member empty of the underlying container object.
Return Value
true if the underlying container's size is 0, false otherwise.
Example
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// priority_queue::empty
#include <iostream> // std::cout
#include <queue> // std::priority_queue
int main ()
{
std::priority_queue<int> mypq;
int sum (0);
for (int i=1;i<=10;i++) mypq.push(i);
while (!mypq.empty())
{
sum += mypq.top();
mypq.pop();
}
std::cout << "total: " << sum << '\n';
return 0;
}
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The example initializes the content of the priority queue to a sequence of numbers (form 1 to 10). It then pops the elements one by one until it is empty and calculates their sum.
Output:
Complexity
Constant (calling empty on the underlying container).
Data races
The container is accessed.
Exception safety
Provides the same level of guarantees as the operation performed on the container (no-throw guarantee for standard container types).