On Friday, 27 March 2015 at 08:43:56 UTC, John Colvin wrote:
> 
> Think of it as compile-time arguments and run-time arguments. First set of parenthesis are compile-time, second are run-time. The parenthesis are optional for compile-time arguments iff there's only one of them.
>

I really appreciate this little explanation, now it makes some sense.