• Timothee Cour via Digitalmars-d-learn (20/20) Aug 21 2014 What would be a good answer to this article?
• Dicebot (1/1) Aug 21 2014 http://dlang.org/phobos/std_typecons.html#.RefCounted
• Timothee Cour via Digitalmars-d-learn (6/7) Aug 21 2014 That doesn't work with classes though; is there any way to get a ref
• Jonathan M Davis (6/15) Aug 21 2014 It can be made to work with classes and probably should be.
• Adam D. Ruppe (7/8) Aug 21 2014 It's own publication date: Feb 2009. The D struct has changed a
• Kagamin (13/26) Aug 21 2014 Even for C# those are not really problems. Returning from

Timothee Cour via Digitalmars-d-learn <digitalmars-d-learn puremagic.com> writes:

What would be a good answer to this article?
http://swiftcoder.wordpress.com/2009/02/18/raii-why-is-it-unique-to-c/

Especially the part mentioning D:{

 using declaration all
provide limited RAII, by allowing resources to have a scoped lifetime, but
none of them readily or cleanly support the clever tricks allowed by C++=E2=
=80=99s
combination of smart pointers and RAII, such as returning handles from
functions, multiple handles in the same scope, or handles held by multiple
clients.
}

This morning I was pointing to some deprecated usage of scope mentioned in
docs (EMAIL:scope classes mentioned in tutorials, but deprecated). The pull
request (https://github.com/D-Programming-Language/dlang.org/pull/637/files=
)
mentions using struct or classes allocated on the stack via
typecons.scoped. However what about the RAII usage mentioned in the above
article that allows C++ to return handles for eg (impossible via scope),
that get deterministically destroyed?

Timothee Cour via Digitalmars-d-learn <digitalmars-d-learn puremagic.com> writes:

On Thu, Aug 21, 2014 at 7:26 PM, Dicebot via Digitalmars-d-learn <
digitalmars-d-learn puremagic.com> wrote:




That doesn't work with classes though; is there any way to get a ref
counted class?

(and btw RefCounted should definitely appear in
http://dlang.org/cpptod.html#raii)

"Jonathan M Davis" <jmdavisProg gmx.com> writes:

On Friday, 22 August 2014 at 03:00:01 UTC, Timothee Cour via 
Digitalmars-d-learn wrote:
 On Thu, Aug 21, 2014 at 7:26 PM, Dicebot via 
 Digitalmars-d-learn <
 digitalmars-d-learn puremagic.com> wrote:




 That doesn't work with classes though; is there any way to get 
 a ref
 counted class?

 (and btw RefCounted should definitely appear in
 http://dlang.org/cpptod.html#raii)

It can be made to work with classes and probably should be. 
There's no fundamental reason why it can't. It's probably just 
more complicated.

- Jonathan M Davis

"Adam D. Ruppe" <destructionator gmail.com> writes:

On Friday, 22 August 2014 at 02:22:16 UTC, Timothee Cour via 
Digitalmars-d-learn wrote:
 What would be a good answer to this article?

It's own publication date: Feb 2009. The D struct has changed a 
lot since then, getting new features ( disable, postblit, more 
reliable destructor) and bugs notwithstanding is pretty well on 
point nowadays.

All the stuff mentioned in there works now.

"Kagamin" <spam here.lot> writes:

On Friday, 22 August 2014 at 02:22:16 UTC, Timothee Cour via 
Digitalmars-d-learn wrote:
 Especially the part mentioning D:{

 declaration all
 provide limited RAII, by allowing resources to have a scoped 
 lifetime, but
 none of them readily or cleanly support the clever tricks 
 allowed by C++’s
 combination of smart pointers and RAII, such as returning 
 handles from
 functions, multiple handles in the same scope, or handles held 
 by multiple
 clients.
 }


functions is not a problem: you just return it and that's it, 
because resource management is decoupled from types, the types 
have no RAII semantics and you can move them around however you 

resource, while in C++ you would need to learn all the black 
magic of RAII before you can declare a RAII type. Multiple 
handles in the same scope are not frequent, nested if's cause 
much more trouble. Handles held by multiple clients are even more 
rare, and it's usually easy to figure out lifetime for non-memory 
resources.