Re: Running a preprocessor from GPS?

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

"EGarrulo" <egarrulo@gmail.com> wrote in message 
news:2ac21830-619c-4145-ab99-d6036bd4ed30@googlegroups.com...
> On Thursday, July 30, 2015 at 8:56:01 PM UTC+2, Randy Brukardt wrote:
>> "EGarrulo" wrote in message
>> ...
>> >
>> >> In Ada, use the stack, if possible!
>> >> In Ada 2005, use containers, if possible!
>> >
>> > Otherwise use C++ and its "shared/weak pointer" support ;)
>>
>> We had a proposal for adding that to Ada, and it just was a complete 
>> mess.
>
> I wonder why.  Smart pointers are conceptually simple.

Sure, but thats not what the proposal was about. And "weak" pointers aren't 
so simple; the proposal required converting them (via a function) to a 
strong pointer before they could be used. And if you put that temporary 
strong pointer into a handy global, you could end up locking the object for 
a long time. Plus there was some sort of automated reference counting.

We decided instead to follow the Ada philosophy and provide the building 
blocks so that people could roll their own useful smart pointers. Thus we 
defined subpools (for arena management of memory), user-defined 
dereferencing (so that the lifetime of references can be managed), and so 
on.

Perhaps some package will get enough usage that it should be promoted to be 
part of the Standard (that's what I meant by suggesting that someone propose 
a package to be added to Ada.Containers), but we didn't think that we had 
enough of an idea how these things would be used to Standardize it in 2012.

> Sure, Ada tries to provide bullet-proof solutions, but that is difficult, 
> for pointers.

Exactly. But what is the point of another half-way safe solution? We already 
have plenty of those (subpools, unchecked deallocation itself, etc.).

                                Randy.