Re: Smart pointers and delegation

["Randy Brukardt" <randy@rrsoftware.com>]

"Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> wrote in message 
news:omblk3$svi$1@gioia.aioe.org...
> On 2017-08-08 00:39, Randy Brukardt wrote:
>> "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> wrote in message
>> news:om3vsc$jhk$1@gioia.aioe.org...
...
>>> Implicit dereferencing semantically does the same. For each visible
>>> operation of the target type it declares an anonymous operation of the
>>> reference type that dereferences and then calls to the original 
>>> operation.
>>
>> I don't see this at all.
>
> You do it with the eyes closed... (:-))

That's possible. I'm not the best at seeing patterns; I'm much more likely 
to write everything from scratch. Thus I don't find use for interfaces, for 
one example.

...
>> It's not really opposite, though, if you want to limit the lifetime of 
>> the
>> reference (even if that limit is potentially a long time).
>
> Why would I want this, if the reference manages the object? The cardinal 
> difference is between object-managed references and reference-managed 
> objects. The former has a very limited use and would prefer to have all of 
> them built-in.

In that case, you definitely need to know precisely when the reference dies, 
so you can "manage the object". If you have a lifetime leak (such as any 
normal access type does), then you can't do that management safely. The 
pattern of the intended use-case of Implicit_Dereference does exactly this. 
Yes, I agree that it would have been better to have an explicit call-back 
(that was the original idea, after all), but that was a lot more complex in 
language and implementation terms. I don't think the complex version was 
going to fly, and the simple version solves the problem that we needed to 
solve. Sometimes, a "meh" idea that you can actually get implemented is 
better than a brilliant idea that doesn't get any traction and thus never 
actually exists anywhere.

                                          Randy.


                                       Randy.