DMD can implicitly convert class pointer to the bool. Is it bug or terrible feature?

[ilya-stromberg]

On Tuesday, 26 November 2013 at 08:23:15 UTC, bearophile wrote:
> Chris Cain:
>
>> If you really want to know when something is global when you 
>> use it then use g prepended before your global names. That's 
>> what a lot of people do to avoid this type of issue.
>
> That is named "relying on hand-managed name conventions for 
> something that could be the job of the compiler type system".

Yes, exactly.
BTW, yesterday I found bug in Vibe.d, see:
https://github.com/rejectedsoftware/vibe.d/issues/406

Reduced example:

void main()
{
	int i;
	i = i;
}

The line `i = i;` does nothing, but compiler doesn't give a 
error. Why?!

Note that `i;` line gives the error:
Error: var has no effect in expression (i)