On 01.02.2013 20:18, monarch_dodra wrote:
On Friday, 1 February 2013 at 19:10:26 UTC, Rainer Schuetze wrote:
On 01.02.2013 09:06, Dmitry Olshansky wrote:
01-Feb-2013 00:32, Rainer Schuetze пишет:
- how do you reference count immutable containers? You'll have to cast
the payload to mutable and assume it is not in read-only memory.
Containers of immutables can have ref-count easily.
And I'd say fully immutable containers are rare case and can rely on GC.
Do you want different implementations of the containers depending on
the mutable/immutable/shared modifier? Would that be possible?
You can only do that on the qualifier of the *parameters*, not the
container itself.
Ok, but that won't help changing reference count semantics, because the
type of the elements are irrelevant here. It's about the container itself.
This is not possible because an S "is a" const(S). If the implementation
of an S was different from a const(S), then you'd violate that. At best,
a const(S) is an S with restricted possibilities, bot not *different*
possibilities.
I guess you would have to convert it to a different type, but it can be
an efficient operation transferring the payload unmodified. Also, when
converting to shared, you might even be able to verify that there are no
other references left (that must be non-sharing).
