Bug or not? "Functions cannot return a function"

[Stefan Koch via Digitalmars-d]

On Thursday, 17 November 2016 at 03:10:33 UTC, Jonathan M Davis 
wrote:
> Regardless, optional parens are one of those features that 
> seems really nice in some situations and gets really annoying 
> in others, and you hit one of those spots where it's annoying.

I would be feasible to only recognize parenthesis-less calls as 
calls in UFCS situations.
The increase in sema-complexity is not high.