The liabilities of binding rvalues to ref

[Peter Alexander]

Is there any intention to address the issue of the lvalue-ness of 
"this"? In C++, *this is always an lvalue, even if the member 
function was called with an rvalue, leading to situations like 
this:

struct Number
{
     void fix() { if (isnan(x)) x = 0; }
     double x;
}

class Collection(T) {
   ref T opIndex(size_t i) { ... }
   ...
}

void fixAll(Collection!Number c) {
   foreach (i; 0 .. c.length) {
     c[i].fix();
   }
}


Here, if Collection changes to return by non-ref then the fix() 
call is still valid, silently doing nothing of value. Analogous 
code in C++ is allowed as well.

Do we intend to fix this as well? I suspect there are use cases 
where such calls are useful, but I can't think of any right now.