How do I clear the std::queue efficiently?

Question

I am using std::queue for implementing JobQueue class. ( Basically this class process each job in FIFO manner). In one scenario, I want to clear the queue in one shot( delet

Answer 1

Author of the topic asked how to clear the queue "efficiently", so I assume he wants better complexity than linear O(queue size). Methods served by David Rodriguez, anon have the same complexity: according to STL reference, operator = has complexity O(queue size). IMHO it's because each element of queue is reserved separately and it isn't allocated in one big memory block, like in vector. So to clear all memory, we have to delete every element separately. So the straightest way to clear std::queue is one line:

while(!Q.empty()) Q.pop();