[phobos] A few minor features

[Walter Bright]

David Simcha wrote:
>
> Andrei pointed that out to me, too.  I think that idiom is a terrible 
> solution because:
>
> 1.  It's too much typing.  Asserts are something you want sprinkled 
> liberally thoughout your codebase, and they should only be removed 
> from release builds if they have a non-negligible impact on 
> performance or might contain sensitive information that you don't want 
> revealed to customers or whatever.  It's absolutely essential that 
> release-mode assert not be a PITA to use.
>
> 2.  It doesn't give file and line numbers.
>

Not the greatest, sure, but not exactly terrible!