Enumeration Type-Safety in D

["Nordlöw"]

What is the state and plans on type-safety of enums in D?

I expected

import std.stdio: writeln;

void main(string args[]) {
     enum E {x, y, z}
     E e;
     writeln(e);
     e = cast(E)3;
     writeln(e);
}

to fail to compile because of D's otherwise strong static 
type/range checking or at least give an RangeException when run.

To my surprise, it instead prints

cast(E)3

Is this really the preferred default behaviour for the majority 
of use cases?