Re: Problem Eliminating constructors

[John English <je@brighton.ac.uk>]

Victor Porton wrote:
> 
> package A is
> 
>   type A_Type is tagged
>     record
>       X: Integer;
>     end;
> 
>   function Create(X: Integer) return A_Type; -- guess what is the body
> 
> end A;
> 
> Then I have
> 
> type B_Type is new A.A_Type with
>   record
>     Y: Integer;
>   end;
> 
> Compiler requires me to override Create as the return type changes.
> But it is meaningless as now I need Create with two parameters
> instead of one.
> 
> What to do?

Take Create out of package A and make it a child of the package:

  function A.Create(X: Integer) return A.A_Type is ...;

Now Create will no longer be a primitive operation of A_Type since
it isn't declared in the same package spec, but you can refer to
it in exactly the same way (except you would need "with A.Create"
to be able to call it).

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