Making generalized Trie type in D

[Roman D. Boiko]

On Monday, 4 June 2012 at 22:21:42 UTC, Dmitry Olshansky wrote:
> And you can fake immutability, buy always picking up an unused 
> slot btw. No need to go beyond logical immutability.
That's applicable in some cases, not in general. But I agree that 
often it is possible to optimize if use cases are known.

My example concern was about fundamental problem of range APIs 
for immutable data structures, which is not possible to emulate: 
popFront is mutating by design.