On Saturday, 24 May 2014 at 18:01:43 UTC, Ali Çehreli wrote:
On 05/24/2014 10:02 AM, w0rp wrote:
> I have been writing my own hashmap which can provide forward
ranges
> usable in @safe pure nothrow functions, because it's going to
be useful
> for creating graph data structures with the same. I came to
writing my
> ranges and I figured out how to do everything right for just
mutable
> hashmaps, but I have no idea how to manage the tail-const
nature of
> ranges in a variety of combinations. I figured out that I
need to
> satisfy the following constraints.
>
> Create a mutable KeyRange over a map which forwards on the
right
> constness for the key type, so the following must be true.
>
> HashMap!(K, V).keys.front -> K
> const(HashMap!(K, V)).keys.front -> const(K)
> immutable(HashMap!(K, V)).keys.front -> immutable(K)
>
> I have encounted some difficulty in trying to write a range
which does
> this.
How timely! :) Jonathan Crapuchettes talked about facing the
same issue in his talk at DConf. Perhaps he will post his
WrapMutability template here or you can wait for his talk on
YouTube.
Ali
I thought someone would say something like that! I'll wait for
the talk I suppose.
