Hiding a type

[Ryan Tarpine <rtarpine@hotmail.com>]

Hello everyone!  I have just started learning Ada, and I am trying to 
use it on my next (personal) project.  That's generally how I learn 
things, by jumping in too deep (It worked to teach myself OCaml, so 
we'll see how this turns out! :)

What I'm wondering is how to hide a private type under a different, 
public name so variables can't be assigned.  I'm not sure how to say it 
best, so here's the simplest example of it:

package Test is
     type Hide is limited private;
private
     subtype Hide is Integer;
end Test;

I want to write functions that will return something of type Hide in a 
way so clients can't do anything except pass it to other functions.  I 
also don't want them to know if I change how I implement it.  (In my 
real program, I'm trying to hide that Foo returns an access type.) 
Please tell how I should actually do this

The exact errors I get are
test.ads:2:10: missing full declaration for private type "Hide"
test.ads:4:13: "Hide" conflicts with declaration at line 2

Thanks in advance,
Ryan