Extended Type Design.

[Tyler Knott]

Chris Nicholson-Sauls wrote:
> As I understand, there will be an implicit cast of mutables to 
> immutables, so assuming 'const' appears under 'invariant' in this list, 
> I would expect|hope it to be 'const Foo*' so that it is passable to 
> either 'const' or 'invariant' typed parameters.  Ie:
> 

Actually, I take back what I said in my previous post in this thread.  Taking the address of a final variable should 
always result in an invariant pointer.  The reason is that invariant references require the data they reference to 
never, ever change whereas const references expect the data they reference to be changed by other 
non-const/non-immutable references to that data.  Obviously, since const references can't guarantee the data they 
reference won't change they can't be cast to immutable references at all, but because const references can still 
guarantee they won't mutate the data they reference immutable references can be freely cast to const references.