Get return type statically

[H. S. Teoh via Digitalmars-d-learn]

On Tue, Jun 28, 2016 at 01:41:03AM +0000, Smoke Adams via Digitalmars-d-learn wrote:
> I have a type
> 
> public class SuperFunction(T)
> {
>   T t;
>   return(T) Do() { return t(); }
> }
> 
> where T is a delegate or function. First, I would like to be able to
> specify that this must be the case for SuperFunction so we can't pass
> non-function/delegates for T.

Try:

	class SuperFunction(T)
		if (is(T == function) || is(T == delegate))
	{
		...
	}


> Second, How to specify the return type of Do to match that of T.

Maybe this?

	import std.traits : ReturnType, Parameters;

	ReturnType!T Do(Parameters!T args) { return t(args); }


T

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INTEL = Only half of "intelligence".