Andreas Winckler <andreas.winckler@frqnet.de> wrote in message
news:3806DC34.1513E8B1@frqnet.de...
> See line 16, the type of the referenced object must be known in advance.
> With "pointer.second_field :=1" the compiler fails. It seems that the
> strong typing restricts the features of polyormism in Ada. Any comments?

This would be illegal in all other OO languages I know of.
For instance, in Java:

public class A {
    int first_field;
}

public class B extends A {
      int second_field;
}

import A;
import B;
public class inheritance_polymorphism {

  public static void main(String[] args) {
    A pointer = new B();

    pointer.second_field = 1;              /* illegal */
    ((B)pointer).second_field = 1;      /* legal */
  }

}

-St�phane


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Stephane Barbey, PhD   phone: +41(31)828.92.17
Paranor AG             fax:   +41(31)828.92.99
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