github.com/LdDl/deque (go): Package deque provides a fast ring-buffer deque (double-ended queue) implementation.  Deque generalizes a queue and a stack, to efficiently add and remove items at either end with O(1) performance.  Queue (FIFO) operations are supported using PushBack() and PopFront().  Stack (LIFO) operations are supported using PushBack() and PopBack().  The ring-buffer automatically resizes by powers of two, growing when additional capacity is needed and shrinking when only a quarter of the capacity is used, and uses bitwise arithmetic for all calculations.  The ring-buffer implementation significantly improves memory and time performance with fewer GC pauses, compared to implementations based on slices and linked lists.  For maximum speed, this deque implementation leaves concurrency safety up to the application to provide, however the application chooses, if needed at all.  Since it is OK for the deque to contain a nil value, it is necessary to either panic or return a second boolean value to indicate the deque is empty, when reading or removing an element.  This deque panics when reading from an empty deque.  This is a run-time check to help catch programming errors, which may be missed if a second return value is ignored.  Simply check Deque.Len() before reading from the deque.
Keywords: data-structures|deque|fifo|generics|lifo|queue|ring-buffer