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?