Are these (known) bugs?

[biozic]

Hi,

I am playing with the to-be-released std.datetime, and encountered these 
errors (the last one concerns std.variant, actually), with dmd 2.052 
(Mac OS X 10.6):

---
import std.array, std.datetime, std.variant;

unittest {
    auto app = appender!(Interval!Date[]);
    auto interval = Interval!Date(Date(2000, 1, 1), Date(2011, 2, 3));
    app.put(interval);
    // Error: datetime.d(20208): Invariant Failure: begin is not before 
or equal to end.
}

unittest {
    Variant[] va;
    ubyte u = 0;
    va ~= u;
    // Error: cannot append type ubyte to type VariantN!(maxSize)[]
}
---

Are these (known) bugs, or do I do anything wrong?
Thanks,
Nicolas