==========C++ Queues==========

The C++ Queue is a container adapter that gives the programmer a FIFO (first-
in, first-out) data structure.

|[[queue_constructors|Constructors]]|construct a new queue|
|[[back]]|returns a reference to last element of a queue|
|[[empty]]|true if the queue has no elements|
|[[front]]|returns a reference to the first element of a queue|
|[[pop]]|removes the first element of a queue|
|[[push]]|adds an element to the end of the queue|
|[[size]]|returns the number of items in the queue|