string <-> null/bool implicit conversion

[via Digitalmars-d]

On Thursday, 20 August 2015 at 19:41:44 UTC, Jonathan M Davis 
wrote:
> On Thursday, 20 August 2015 at 17:50:11 UTC, Steven 
> Schveighoffer wrote:
>> if(arr != null)
>
> Definitely don't do that. IMHO, "== null and "!= null" should 
> be illegal. If you really want to check for null, then you need 
> to use "is null" or "!is null", whereas if you want to check 
> that an array is empty, check its length or call empty. By 
> using "== null" or "!= null", you tend to give the false 
> impression that you're checking whether the object or array is 
> null - which is not what you're actually doing.

I disagree. `is null` is the one that should be illegal. `is` is 
supposed to do a bitwise comparison, but `null` is usually just a 
pointer/reference, while a slice consists of both a reference and 
a length. Which of those are compared?