Queue's Operations from the C++ Standard Template Library

bool empty()

Returns True if the queue is empty, and False otherwise.

T& front()

Returns a reference to the value at the front of a non-empty queue. There is also a constant version of this function, const T& front().

void pop()

Removes the item at the front of a non-empty queue.

void push(const T& foo)

Inserts the argument foo at the back of the queue.

size_type size()

Returns the total number of elements in the queue.