[Brian Schroeder <spam0504 / bssoftware.de>, 2004-05-20 14.23 CEST]
> Thanks for your answer. I should have looked in the raa by myself. Just a
> question regarding array as deque. How efficient is it? Is all the data
> shifted through the array every time I push something at the front and
> remove it from the back, or is it organized more efficiently?

If I'm not mistaken, #push (appends at the end), #pop (remove last) and
#shift (remove first) are efficient (#shift moves the pointer). #unshift
(insert at beginning) moves all elements.

But I can be mistaken.