workaround for closure problem needed

[BCS]

Reply to Mandel,

> Hi,
> 
> I have a problem with closures and D 1.024.
> D2 does have full closure support, but I have to stick with D1
> for now.
> Problem: variable "state" changes silently when the anonymous
> function goes out of the scope of function filter.
> Therefore the program does print out "item" only once.
> My question is if there is a workaround ("static state" wouldn't be
> thread safe)?
> 

wrap the stuff (state + the local function) in a local struct, new off an 
instance at the top of the outer function, convert the outer function's access 
to "state" into "inst.state" and then replace the anon delegate with "&inst.fn". 
Crude and a bit ugly but it works.

OTOH (WARNING: TOTAL HACK) if you want to go one step cheaper; state is 32bits, 
the same as a void*.

struct Wrap
{
  bool func(A item)
  {
    Cast c;
    c.pt = this; 
    return (item.getState == c.ui); //should always return true
  }
}

union Cast {Wrap* pt; uint ui;}

//to get dg;

Cast c;
c.ui = state;
&c.pt.func;

this works only if state is the only thing used and if it is not changed.