Re: Problem trying to implement generics.

[Andy <startrek.nospam@ozonline.com.au>]

Ayende Rahien wrote:
> 
> I've just started to learn Ada, and I've some problem solving some problems.
> 
> Here is the spec I'm trying to compile:
> 
> with Ada.Finalization;
> generic
>  type data_type is private;
>  type Sort_by is private;
> package Binary_Trees is
>  type binary_Tree is new Ada.Finalization.controlled with private;
>  
  [snip]
>
> end Binary_Trees;
> 
> I trying to put the defination of Node in the body, but it results in
> compilation error, is there some way to put the defination in the body? Or
> does it matter naught, because it's on the private part of the package?
> 
> Since it's a binary tree, I've to have > working on all types that sort_by
> work on.
> How do I force it?
> At the moment, I've three compilation errors when I'm trying to use > on
> sort_by data.
> Here is the error:
> bintree.adb: Error: line 43 col 25 LRM:8.4(1), Binary operator ">" between
> Sort_by and Sort_by not directly visible, use clause or conversion might be
> needed

Ayende,
Expect you need something like this:
 
generic
  type data_type is private;
  type Sort_by is private;
  with function "<" (Left, Right: in Sort_By) return Boolean;
package Binary_Trees is

   -- as before

end Binary_Trees;

-- 
Regards,
Andy