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Date: Mon, 02 Jun 2008 16:30:29 +0200
From: Georg Bauhaus <rm.dash-bauhaus@futureapps.de>
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Subject: Re: Ada: Inheritance of generics
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Date: 2008-06-02T16:30:29+02:00
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Dennis Hoppe schrieb:
> Hi,
> 
> I managed to implement a generic parent class and create a generic unit, 
> which is a child of the first one. I wonder, why I have access to 
> procedures and functions of the parent class, if I am "within" the child 
> unit, but if I am "outside", the compiler complains that no selector for 
> a specified function exists.

Do you mean a parent type and a derived type which happen
to be declared in package templates?

The name "generic child package" has a meaning in Ada that
does not necessarily have something to do with types.
Just in case you are used to thinking in C++, a package
is not always the same as a class. For example, you can
have two types within the same package.

Only types, i.e. things declared using the resered word
"type", can  derive from other types. Likewise, a
package instance is made from a generic package which
acts as a template for packages. But packages are not types.
So this does not work:

package Child is new Parent.Object;


function Example return Integer;
is not associated with type Object; its profile does
not mention Object.
Function Example is somewhat like a static member function
in C++.


  -- Georg