Attributes lost in TypeInfo, please advise

[Jakob Ovrum via Digitalmars-d]

On Thursday, 12 February 2015 at 12:59:39 UTC, Steven 
Schveighoffer wrote:
> I think given the necessity of the above (which was not 
> discussed or noticed in that bug report), we should add a way 
> to call the true destructor properly in the compiler.
>
> -Steve

I think these do the right thing with only marginal overhead:

---
void destructRecurse(S)(ref S s)
     if (is(S == struct))
{
     static if (__traits(hasMember, S, "__dtor"))
         s.__dtor();

     foreach_reverse (ref field; s.tupleof)
     {
         alias Field = typeof(field);
         static if (is(Field == struct) && 
hasElaborateDestructor!Field)
             destructRecurse(field);
     }
}

void postblitRecurse(S)(ref S s)
     if (is(S == struct))
{
     foreach (ref field; s.tupleof)
     {
         alias Field = typeof(field);
         static if (is(Field == struct) && 
hasElaborateCopyConstructor!Field)
             postblitRecurse(field);
     }

     static if (__traits(hasMember, S, "__postblit"))
         s.__postblit();
}
---
I notice now it is missing proper handling of fixed-length 
arrays: I'll add that. Anything else missing?

Efficiency-wise they should at least be a lot better than the 
status quo - two indirect calls. For absolutely optimal 
performance it relies on the inliner, but if it is demonstrated 
to be a problem compared to the compiler-generated solution, it 
could always generate optimal code with some hands-on string 
mixins :)

I am aware that std.traits is not available in object_.d - the 
hasElaborate* templates are fairly simple and easy to reimplement.