Re: "" gives an empty string, while "".idup gives null

[simendsjo]

On 03.08.2011 15:49, bearophile wrote:
simendsjo:
void main() {
      assert(is(typeof("") == typeof("".idup))); // both is immutable(char)[]

      assert(""      !is null);
      assert("".idup !is null); // fails - s is null. Why?
}

I think someone has even suggested to statically forbid "is null" on strings :-)

Bye,
bearophile

How should I test for null if not with "is null"? There is a difference 
between null and empty, and avoiding this is not necessarily easy or 
even wanted.
I couldn't find anything in the specification stating this difference.
So... Is it a bug?