union mutability

[Jonathan M Davis via Digitalmars-d-learn]

On Thursday, August 25, 2016 18:27:25 Jack Applegame via Digitalmars-d-learn 
wrote:
> On Thursday, 25 August 2016 at 17:01:40 UTC, Meta wrote:
> > This should be fixed pretty soon:
> > https://github.com/dlang/dmd/pull/5940
>
> Bye-bye immutable classes. :'(

Why? I don't know exactly what that PR is supposed to do, but std.datetime
uses immutable time zone objects, and if that PR made it so that you
couldn't have an immutable instance of a class, then it would have failed
the auto-tester. And it clearly doesn't stop having unions with immutable
members, or it would have failed to compile because of Rebindable (though it
may be that Rebindable can no longer be used in @safe code).

- Jonathan M Davis