[Dlang-study] [lifetime] Initial thoughts on lifetime management

[Andrei Alexandrescu]

On 10/28/2015 09:44 AM, Timon Gehr wrote:
> opInc and opDec are still useful. E.g. one could @disable opInc to
> obtain unique class references. (opInc and opDec are basically just
> class reference based versions of this(this) and ~this().)

Noted.

> How does the compiler lose control with opInc/opDec? It could still fuse
> them.

Fusing them relies on the compiler knowing the effects are additive 
(three successive opInc()s mean += 3 etc) and also that opInc() and 
opDec() cancel each other. Allowing the user to define them arbitrarily 
prevents the compiler from doing some of these things, or limits what 
the user can do drastically enough to just mandate one implementation.

> If we want to be able to elide the vptr, I don't think a common root
> class can work.

Makes sense.

> How to specify the allocator for a @rc class?

I don't know, it's a good topic for discussion. Ideas?


Andrei