What I find particularly amusing is that this patch is based on making unshift bigger, slower, and wasteful of memory. Optimizations are certainly not always obvious! The way it works is that when you call unshift and it needs to extend your array, it adds to the request the size of the current array. The reason is that extending the array at the front involves moving the whole thing, and this is expensive so you want to do it as seldom as possible. In big-O notation with this change
takes O(n) instead of O(n*n). :-)push @foo, 1 for 1..$n;
The patch has been accepted.
It is in the current development snapshot.