lazy variables

[aliak]

Hi,

Is there any notion of lazy vars in D (i see that there're 
parameters)?

i.e:

struct S {
   //...
   int y;
   //...
}

lazy S x = () {
     // do some heavy stuff
}();

if (condition) {
   func(x.y); // heavy stuff evaluated here
}

Cheers,
- Ali