Checking if a string is null

[Regan Heath]

Frits van Bommel wrote:
> Or would you prefer a segfault or diagnostic when accessing 
> (cast(T[])null).length? 

No, definately not.  This is one of the things I love about arrays, 
they're both value and reference type.  It takes a while to get your 
head round (if the many discussions on these forums are any indication) 
but once you have it worked out it's quite powerful.  In fact it's the 
reason slicing can work the way it does.

Further, for those cases where we do not care to differentiate between 
null and "" checking length == 0 is the perfect solution.

I'm not interested in an array implementation which is 'pure' in any 
academic sense but rather one which is consistent in that null arrays do 
not become empty and vice-versa under any conditions (other than 
explicitly assigning those values).

For example:

In the past setting length to 0 would free the data pointer.  The result 
of which was that a zero length (empty) array became a non-existant 
(null) array.

And the problem we have now is that calling .dup on an empty array 
results in a null array.

It is cases like these which I was to remove.

The other thing I want is for == to tell me that null and "" are not the 
same.

I suspect very little existing code is relying on the existing behaviour 
as it will likely be checking length as opposed to comparing to "" or 
null (note; comparing with == not checking identity with "is").

Regan