Re: RCArray is unsafe

[Andrei Alexandrescu via Digitalmars-d]

On 3/2/15 12:37 PM, Walter Bright wrote:
On 3/1/2015 12:51 PM, Michel Fortin wrote:
That's actually not enough. You'll have to block access to global
variables too:
     S s;

     void main() {
         s.array = RCArray!T([T()]);   // s.array's refcount is now 1
         foo(s.array[0]);           // pass by ref
     }
     void foo(ref T t) {
         s.array = RCArray!T([]);      // drop the old s.array
         t.doSomething();              // oops, t is gone
     }

Thinking about it, there are many other ways this can happen. At the
moment, I'm stuck thinking of a solution other than requiring foo() to
be pure. Anyone have ideas?

I have a solution (as in working implementation), but also a deadline 
that's staring me in the face so this will have to wait a couple more days.

I also have a bit of an attack to const/immutable support but that's 
less good (allows too much freedom).


Andrei