[hackathon] FreeTree is FreeList on autotune

[Andrei Alexandrescu via Digitalmars-d-announce]

On 5/2/15 4:11 AM, Meta wrote:
> I forget what the rules are for allocators exactly, but isn't something
> only an allocator if it defines allocate, deallocate, owns, etc.? It
> just seems weird that you mentioned something that I thought was implicit.

All members except alignment and allocate are optional. There are 
allocators that can't deallocate, such as Region. -- Andrei