foreach, tupleof

[Ellery Newcomer]

Hello.

In D1, this code fails:

void foo(S)(ref S s){
   foreach(ref k; s.tupleof){
     k = 1;
   }
}

struct K{
   int g;
}

void main(){
   K k;
   foo(k);
   assert(k.g == 1);
}


test.d(5): Error: no storage class for value k

(referring to 'k = 1;')

Is this an expected error, and is there a good way to get the semantics 
to actually work?