Re: [boost] Review of a safer memory management approach for C++?

Subject: Re: [boost] Review of a safer memory management approach for C++?
From: Fernando Cacciola (fernando.cacciola_at_[hidden])
Date: 2010-06-03 23:14:25

Hi David,

>> Trying to over design a program to avoid all shared ownership is
>> what make C++ programming so unproductive and has all the negative
>> consequences described in Section 1 in:
>>
>>      http://www.cs.sandia.gov/~rabartl/TeuchosMemoryManagementSAND.pdf
>>
>> Designs with object sharing can be much less complex overall than
>> designs with sharing.  You just need decent tools to detect circular
>> reference problems (and that is what the Teuchos::RCP class has).
>
> Well, I fundamentally disagree with all of the above.  Overuse of
> runtime polymorphism, thus dynamic allocation, and thus shared
> ownership (it's almost an inevitable progression) is one of the things
> that has made C++ programming unproductive, and those people I know
> who most zealously avoid it tend to be more productive than everyone
> else.  IMO.
>
I couldn't agree more.

C++ best practices has been evolving from dynamically-polymorphic designs to 
statically-polymorphic ones, but rather slowly, so I don't expect to see most 
competent programmers do the mental migration just yet. This requires a 
mindshift comparable to that of structured -> OO programming.
I even wonder if this isn't a new paradigm altogether.

For instance, it's been so long since I last wrote a virtual function that 
recently, I made the silly mistake of forgetting that, in a derived class, an 
overrided function doesn't have to specify the virtual keyword ;)

Anyway.

Speaking of value-semantics and moving (as opposed to sharing) objects... I 
recall a CUJ article in the mid 90's with a smart pointer offering a handle/body 
solution for value-semantics of dynamically allocated objects. I don't remember 
the details (such as using COW or what), nor the author, but I do remember that 
it was, IMO, simply brillant, but way ahead of its time. Compilers at the time 
could barely template two and two toghether, so the actual utility was rather 
impractical.

I just thought that, maybe, C++0x finally got what it takes to tackle on 
something like that?

IMO this would make for a terrific boost project, to the level of what 
shared_ptr used to be 15 years ago.

Anyone? (I can't get into something like that without a time machine I'm afraid :)

Best

--
Fernando Cacciola
SciSoft Consulting, Founder
http://www.scisoft-consulting.com