He said *new* library type, so obviously it would not break
existing code since nothing uses it.
Wednesday, 5 February 2014 at 00:07:30 UTC, Adam Wilson wrote:
On Tue, 04 Feb 2014 15:51:35 -0800, Andrei Alexandrescu
<[email protected]> wrote:
Consider we add a library slice type called RCSlice!T. It
would have the same primitives as T[] but would use reference
counting through and through. When the last reference count is
gone, the buffer underlying the slice is freed. The underlying
allocator will be the GC allocator.
Now, what if someone doesn't care about the whole RC thing and
aims at convenience? There would be a method .toGC that just
detaches the slice and disables the reference counter (e.g. by
setting it to uint.max/2 or whatever).
Then people who want reference counting say
auto x = fun();
and those who don't care say:
auto x = fun().toGC();
Destroy.
Andrei
I am assuming that you ignoring cyclic-refs for now. And
dealing with them would mean that you would need something like:
auto @weak x = fun();
Since the compiler cannot figure out that this is supposed to
be weak or not it would assume strong as that is the majority.
Second thought. Why is their an extra step for those of us who
don't want the GC. I know there has to be an extra step for
some people, but I feel that we should make the simplest option
the default and then open up avenues for more advanced control
for people who want it. ARC is not as simple to understand as a
GC for newbies, and ARC requires more careful control, so why
not make getting into ARC a little harder, that way we prevent
heartache for new people. So something more like:
auto x = fun().toARC();
I can't imagine any situation where you could go from ARC to GC
that could not also go from GC to ARC, they have to be
equivalent operations to do that anyways.
In the design world you make the simple option easy and more
the more advanced options harder to get at to reduce the chance
that the user accidentally shoot themselves in the foot. And
the guys who want to the advanced options are power users
anyways, they expect to have to work at it a little more.
Related third thought. This goes against the current paradigm
and will subtly break existing D code that has cyclic-refs in
it.
