Has truth of arrays always acted like this?

[Mike Parker]

Bill Baxter wrote:
> Bill Baxter wrote:
>> I could have sworn there was a big discussion just recently about how 
>> "null" and "empty" were the same thing with D arrays and some people 
>> were arguing that should change.  But at least with the most recent D 
>> v1.022, it seems the truth value of uninitialized and empty arrays 
>> *are* different.  Has it always been that way?
> 
> I think maybe the discussion I was remembering was about comparison with 
> null.  Indeed (a==null) is true for both uninitialized *and* length==0 
> arrays.
> 
> That seems completely backwards to me.  If anything, a==null should be 
> the one that checks if a has a buffer allocated at all, and if(a) should 
> be the one that checks for any form of emptiness.
> 
> Barring that, they should just behave the same.
> 
> --bb

I recall a recent discussion specifically about empty vs. null strings, 
i.e. an empty string ("") is equivalent to a null string:

char[] s1 = "";
char[] s2 = null;

if(s1 == s2) writefln("equal");

This will evaluate to true.