* inheritance and private overiding
@ 2000-05-04 0:00 tmoran
2000-05-04 0:00 ` Robert A Duff
0 siblings, 1 reply; 2+ messages in thread
From: tmoran @ 2000-05-04 0:00 UTC (permalink / raw)
One compiler refuses to compile this code, giving the indicated
error message. Other compilers accept it just fine and print
"in test1" then "in test2". Who's right?
-----------------
package test1 is
type Root is tagged null record;
procedure P(X : in out Root);
end test1;
with ada.text_io;
package body test1 is
procedure P(X : in out Root) is
begin
ada.text_io.put_line("in test1");
end P;
end test1;
with test1;
package test2 is
type Branch is new test1.Root with private;
private
type Branch is new test1.Root with null record;
procedure P(X : in out Branch);
end test2;
with ada.text_io;
package body test2 is
procedure P(X : in out Branch) is
begin
ada.text_io.put_line("in test2");
end P;
end test2;
with test1, test2;
package test3 is
type A is new test1.Root with null record;
type B is new test2.Branch with null record;
end test3;
with test3;
procedure test is
X : test3.A;
Y : test3.B;
begin
test3.P(X);
test3.P(Y); -- One compiler says "expected type A, found type B"
-- others have no complaints
end test;
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: inheritance and private overiding
2000-05-04 0:00 inheritance and private overiding tmoran
@ 2000-05-04 0:00 ` Robert A Duff
0 siblings, 0 replies; 2+ messages in thread
From: Robert A Duff @ 2000-05-04 0:00 UTC (permalink / raw)
tmoran@bix.com writes:
> One compiler refuses to compile this code, giving the indicated
> error message. Other compilers accept it just fine and print
> "in test1" then "in test2". Who's right?
I don't see anything illegal in this program.
But I could be missing something.
- Bob
> -----------------
> package test1 is
> type Root is tagged null record;
> procedure P(X : in out Root);
> end test1;
>
> with ada.text_io;
> package body test1 is
> procedure P(X : in out Root) is
> begin
> ada.text_io.put_line("in test1");
> end P;
> end test1;
>
> with test1;
> package test2 is
> type Branch is new test1.Root with private;
> private
> type Branch is new test1.Root with null record;
> procedure P(X : in out Branch);
> end test2;
>
> with ada.text_io;
> package body test2 is
> procedure P(X : in out Branch) is
> begin
> ada.text_io.put_line("in test2");
> end P;
> end test2;
>
> with test1, test2;
> package test3 is
> type A is new test1.Root with null record;
> type B is new test2.Branch with null record;
> end test3;
>
> with test3;
> procedure test is
> X : test3.A;
> Y : test3.B;
> begin
> test3.P(X);
> test3.P(Y); -- One compiler says "expected type A, found type B"
> -- others have no complaints
> end test;
^ permalink raw reply [flat|nested] 2+ messages in thread
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2000-05-04 0:00 inheritance and private overiding tmoran
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