To: J3                                                          08-281
From: John Reid
Subject: Interpretation of intrinsics EXTENDS_TYPE_OF and SAME_TYPE_AS
Date: 2008 October 14

NUMBER: F03/xxxx
TITLE: Definitions of EXTENDS_TYPE_OF and SAME_TYPE_AS
KEYWORDS: EXTENDS_TYPE_OF SAME_TYPE_AS
DEFECT TYPE: Clarification
STATUS: J3 consideration in progress

QUESTION:
The arguments of EXTENDS_TYPE_OF and SAME_TYPE_AS are required to
be of extensible type. Does this restriction apply to the declared
type, the dynamic type, or both?

ANSWER:
They were intended to apply only to the dynamic type. Edits are supplied
to clarify this.

DISCUSSION:
It is made clear that MOLD of EXTENDS_TYPE_OF is allowed to be
unlimited polymorphic. It was intended that all the others also
be allowed to be unlimited polymorphic.

EDITS:

[316:16] In 13.7.38, EXTENDS_TYPE_OF, argument A, replace
"of extensible" with "whose dynamic type is an extensible".

[316:17] In 13.7.38, EXTENDS_TYPE_OF, argument MOLD, replace
"of extensible" with "whose dynamic type is an extensible".

[347:30] In 13.7.101, SAME_TYPE_AS, argument A, replace
"of extensible" with "whose dynamic type is an extensible".

[348:1] In 13.7.101, SAME_TYPE_AS, argument B, replace
"of extensible" with "whose dynamic type is an extensible".

SUBMITTED BY: John Reid

HISTORY: