Can a member function return a delegate to itself?

[teales]

BCS Wrote:

> Steve Teale wrote:
> > Something like:
> > 
> > class Foo
> > {
> >     int a;
> > 
> >     this() { a = 0; }
> > 
> >     void delegate(int) sum(int n) 
> >               { a += n; return cast(void delegate(int)) &this.sum; }
> > }
> 
> as mentioned, the reason this isn't directly doable is that the type is 
> undefinable. However this is strictly a limitation of the D Syntax and 
> their is no problem with actually doing it if you can tell DMD how. I 
> have does this using typing tricks before:
> 
> 
> struct S
> {
> 	S delegate(int,int) dg;
> }
> 
> struct O
> {
> 	int k;
> 	S go(int i, int j)
> 	{
> 		O* o = new O
> 		o.k = k+i+j;
> 		S ret;
> 		ret.dg = &o.go;
> 		return ret;
> 	}
> }

I also think your solution is nifty. So the answer to my question is rather like what you suggested, but you have to add an opCall to S, as in:

import std.stdio;

struct S
{
        S delegate(int) dg;
        S opCall(int n) { dg(n); return *this; }
}

struct O
{
        int a;
        S sum(int i)
        {
                a += i;
                S ret;
                ret.dg = ∑
                return ret;
        }
}


void main(char[][] args)
{
   O o;
   o.sum(1)(2)(3);
   writefln("%d", o.a); // prints 6 as desired
}

It was just a curious question in the first place but you never know, somebody might find a use for it.