const?? When and why? This is ugly!

[Steven Schveighoffer]

On Sun, 08 Mar 2009 20:51:39 -0700, Andrei Alexandrescu wrote:

> Walter Bright wrote:
>> Steve Schveighoffer wrote:
>>> Walter: Use invariant when you can, it's the best! User: ok, how do I
>>> use it?
>>> Walter: You need to cast mutable data to invariant, but it's on you to
>>> make sure nobody changes the original mutable data.  Casting
>>> circumvents the typesystem, so the compiler can't help you. User: :(
>> 
>> Unfortunately, we could not come up with a typesafe scheme for going
>> from mutable to immutable that was reasonable. The transition is up to
>> the user to do correctly, but it isn't a terrible burden, and is simple
>> to get right.
> 
> In fact, since we last discussed that, dmd technology has made enough
> strides (particularly wrt manipulation of copies) that we can define
> Unique!T and something a la Java's StringBuilder with ease.
> Unfortunately current bugs in constructor implementation delay
> definition of such artifacts.

Yes, please fix!

-Steve