Type safety: excellent, if you use @safe you have to tell the compiler you're doing nasty things with it. `cast` is a keyword so you can easily see where it is being done.

Memory: very good with @safe (I've not use rust so I can't compare), there are a few holes in the corners. @safe is not the default though, although it is transitive so if main is safe then everything else has to be @safe or @trusted.

Thread: not so much, we're working on it. You can do thread safe designs but it is ultimately on the programer to not stuff up.