Bulk allocation and partial deallocation for tree data structures.

[Filip Bystricky via Digitalmars-d-learn]

Oh and I forgot to mention: another use-case for this would be 
for arrays. For manually managed arrays like std.container.array, 
it would make it possible to transfer ownership of individual 
objects from the array back to the program after the array goes 
out of scope. For gc slices, it could enable some gc 
implementations to deallocate parts of an array even if there are 
still references pointing inside that array.