is(T == function)

[Steven Schveighoffer]

I know this is an old issue, and I found this old bug to describe it  
(helping someone in a D.learn thread):  
http://d.puremagic.com/issues/show_bug.cgi?id=3464

But my question is, what is the value of T in *expected* usage.  The bug  
gives the example:

is(typeof(*T.init) == function)

to test for a function pointer, but I tried this:

is(main == function)

And that doesn't work, but this does:

is(typeof(main) == function)

So, my question is, what is typeof(main)?  I tried pragma(msg,  
typeof(main).stringof) and I get "void()()", which doesn't compile.

Given how ridiculously special-cased is expressions are anyways, can we  
just define is(T == function) to do something expected?  I can't think of  
a single "normal" use case that doesn't involve typeof or init.

I'd like to see either of these work instead of what we have:

is(main == function)
is(&main == function)

I think the latter would be the most useful, and consistent with  
delegates, especially since we got rid of declaring a function type (not  
function pointer type) in recent times (I think Don did this to prevent  
some kooky C legacy bug).

-Steve