Reflection: is type an inner class

[Tyler Jameson Little]

Say I have something like this:

     class A {
         class B {
         }

         B b;
     }

Right now, I have a loop that does something like this (taken 
from orange project):

     foreach (i, type; typeof(A.tupleof)) {
         enum name = A.tupleof[i].stringof[1 + A.stringof.length + 
2 .. $];
     }

This gets all members of class A (in this case only b), but I 
can't 'new' the class because it needs the context of the 
instance of A. So, I need to check (preferably at compile time) 
if b's type is an inner class or an outer class. If it's an inner 
class, I'll need to instantiate it with the reference of A.

std.traits doesn't seem to have anything useful. I'd like to know 
the following:

* is b's type instantiatable (is that a word?) without extra 
information?
* is b's type an inner class (needs reference to instantiate)

In my code, I have a reference handy, so I just need to know how 
to instantiate it.

I saw the macro 'compiles' in the traits documentation 
(__traits(compiles, ...)). Do I need to do something with this?