struct and default constructor

[dcrepid via Digitalmars-d]

On Friday, 10 October 2014 at 08:03:49 UTC, ketmar via 
Digitalmars-d wrote:
> On Fri, 10 Oct 2014 01:32:51 +0000
> dcrepid via Digitalmars-d <digitalmars-d at puremagic.com> wrote:
>
>> So no possibility of using objects as resource acquire/release 
>> mechanisms.
>> I assume using scoped with class objects will have a similar 
>> problem..
> no, stack-allocated object is GC root, so anything it holds 
> reference
> to will not be destroyed until stack object is alive. so 
> destructor of
> stack-allocated object *can* be used for doing cleanup.
>
> but you can use templates to build your "anchor" structs. it's 
> hard to
> say without concrete code samples.

What I mean with the scoped objects is that you still need to 
provide a constructor with parameters, yes? I will have to try 
this out myself, but I've avoided it since some people seem to 
indicate this is going to be deprecated..

Basically what I was doing code-wise was creating a 'FixedBuffer' 
structure, which would have its size passed as a template 
parameter.  The constructor would do a malloc on it, and all the 
checks for bounds would only need to rely on that template 
parameter. Net result is that the cost of having a pretty safe 
bounds-checked buffer was just the size of one pointer.

I *sorta* get the whole concept of being able to easily reason 
and work with structures in D, but why then does it have a 
destructor and a way to disable a default constructor, along with 
operator overloads and whatnot.  It seems to me its trying to be 
object-like and POD-like at the same time which doesn't mesh well.

As far as the 'scoped' object, I was referring to default 
construction - is it possible?  Or do I need to use Walter's 
factory production workaround everytime I want something with 
deterministic create/destroy properties in this context?

I would very readily accept using objects over structs if they 
had a guarantee of when they are destroyed, and weren't as risky 
to pass around as C pointers (i.e. possibility of them being 
null).