Get the return type of the function

[Ivan Kazmenko via Digitalmars-d-learn]

On Wednesday, 3 February 2016 at 22:09:37 UTC, sigod wrote:
> On Wednesday, 3 February 2016 at 19:21:06 UTC, Meta wrote:
>> Ah, I see. I'd like to test something; can you please change 
>> `(a) => a * a` to
>> `(int a) => a * a` and post the results?
>
> This works.
>
> http://dpaste.dzfl.pl/92c254ef6cf6

Seems reasonable: `(int a) => a * a` has return type `int` but 
just `(a) => a * a` does not yet know the type of `a`, and so can 
not tell the return type.