I measured this against master branch and found no statistical
difference. Since this code is simpler and logically superior due to
always leaving sufficient unused capacity when growing, it is preferred
over status quo.
This is my penance for baiting andrew into deleting the existing generic
queue data structures with my talk of "too many ring buffers".
The new Reader and Writer interfaces are excellent ring buffers for many
use cases, but a generic queue container type is now missing.
This new double-ended queue, known more succinctly as a deque, is
implemented from scratch based on the API design lessons learned from
ArrayList over the years.
The API is not yet as featureful as ArrayList, but the core
functionality is in place and I will be using this in my personal
projects shortly. I think it makes sense to add further functions as
needed based on real-world use-cases.
