Persistent list

[Dicebot via Digitalmars-d]

On Sunday, 15 November 2015 at 14:23:05 UTC, Jonathan M Davis 
wrote:
>> As I mentioned, he's okay with changing the language to make 
>> the casts well defined. -- Andrei
>
> Well, that's a big change, since it pretty much means that D's 
> const isn't physical const anymore, and Walter has been _very_ 
> insistent about that in the past - to the point that he's 
> argued that C++'s const is outright useless because it isn't 
> physical const. If casting away const and mutating is 
> well-defined behavior, then we basically have C++'s const 
> except that it's transitive ...

Casting away _const_ is already legal if programmer can himself 
guarantee underlying object has mutable origin (i.e. not 
available via immutable reference), by the very definition of 
const. It is casting away immutable and mutating that is strictly 
UB.