How will we fix opEquals?

[so]

> We _must_ have it there, so anyone overriding those functions _must_
> use it for those functions. They could create non-const versions in  
> addition to
> the const ones,
It is the whole point, they can't.

> but they _must_ create the const versions. They're stuck.
> There's no way around it without breaking the type system. structs avoid  
> the
> problem, because they don't have to worry about polymorphism, but classes
> obviously do.
Structs avoid because unlike classes structs don't share the same base  
class.