On Thursday, 2 January 2014 at 14:59:55 UTC, Adam D. Ruppe wrote:
On Thursday, 2 January 2014 at 13:30:06 UTC, monarch_dodra
wrote:
Currently, this is not possible. Or if it was, it would have a
*very* high code cost inside RBT.
It is possible in theory; RBT returns a separate Range type
with opSlice that is implemented in terms of pointers to node.
(This is hidden by an alias RBNode!Elem* Node, which gets in
the way, but if those were inout(RBNode)* or const()* it'd
work).
We can have mutable pointers to const data, which would work
with the range. So opSlice returns a mutable range that points
back to const data.
But in this case, none of the functions in rbtree use const nor
inout, and there's some caching (e.g. _left and _right) that
I'm not sure can work with it at all anyway. In a const node,
the left and right properties won't work..
Right. Doable, but not trivially so :/
Array might be able to pull it off more easily.
That said, it would only solve the "const container => Range"
issue, but the "const range" problem itself would remain :(
