Very limited shared promotion

[Manu]

On Wed, Jun 19, 2019 at 1:11 PM Manu <turkeyman at gmail.com> wrote:
>
> On Wed, Jun 19, 2019 at 12:20 AM Timon Gehr via Digitalmars-d
> <digitalmars-d at puremagic.com> wrote:
> >
> > On 18.06.19 16:14, Timon Gehr wrote:
> > > On 18.06.19 16:13, Timon Gehr wrote:
> > >>
> > >> int sum(){ // note: just to illustrate the concept
> > >>      int result=0;
> > >>      foreach(i;iota(1000).parallel){
> > >>          static assert(is(typeof(result)==shared(int)));
> > >>          result.atomic!"+="(i);
> > >>      }
> > >>      static assert(is(typeof(result)==int));
> > >>      return result;
> > >> }
> > >
> > > Return type should have been int, of course...
> >
> > And there should have been is expressions. Getting tired from pushing
> > back against all the nonsense. Just note that if you can make the above
> > work with useless qualified capturing, you can do so with useful
> > qualified capturing and this is so blatantly obvious that it causes me
> > physical pain that Manu honestly does not see it.
>
> I can't see it because the design specifically inhibits that static
> assert in the loop body.
> But I will revoke my opinion on this matter; arguing will only slow it
> down. If you know how to make that *EXACT* code you wrote above work,
> then we are done here and I will buy you a years supply of beer.
>
> Coupled with removing read/write access from shared, that is
> everything I need to go away and leave you all alone.

I'll just tweak your example one more little bit to make sure
absolutely everything I care about is captured correctly:

struct S {
    int result;
    void inc(int i) shared { result.atomic!"+="(i); }
}
int sum(){
    S s;
    foreach(i; iota(1000).parallel){
        static assert(is(typeof(s) == shared(S)));
        s.inc(i);
    }
    static assert(is(typeof(s) == S));
    return s.result;
}

The combinations of primitives at work here will solve every challenge
I'm aware of in our engine.