CVS difference for ais/ai-presentation.txt

Differences between 1.3 and version 1.4
Log of other versions for file ais/ai-presentation.txt

--- ais/ai-presentation.txt	1999/07/29 00:51:02	1.3
+++ ais/ai-presentation.txt	2000/03/14 00:05:55	1.4
@@ -1305,3 +1305,34 @@
 
 ****************************************************************
 
+From: Dr Steve Sangwine [S.J.Sangwine@TALK21.COM]
+Sent: Wednesday, December 15, 1999 9:12 AM
+To: ADA-COMMENT@ACM.ORG
+Subject: [Ada-Comment] LRM obscure on generic formal types with unknown
+discriminants
+
+!topic LRM obscure on generic formal types with unknown discriminants
+!reference RM95-12.5(2)
+!reference RM95-12.5(10)
+!reference RM95-12.5.1(6)
+!from Stephen J. Sangwine (S.Sangwine@IEEE.org) 99-12-15
+!definite indefinite
+!discussion
+
+A private formal type in a generic package can be declared as
+type X(<>) is [limited] private. This permits the actual
+subtype to be indefinite (example an unconstrained array
+subtype) but does not allow the body to use the formal type
+in a context that would require a definite subtype (example
+object declaration). The LRM is unclear on this whereas the
+Ada 95 Rationale (Intermetrics, Inc., January 1995) gives a
+very clear discussion at Section 12.1 (The Contract Model).
+Places where the LRM is lacking in clarity include the index
+where '[D|d]efinite' refers only to 12.5.1(23), K(50) and
+3.3(23) and not 12.5.1(6). Note 8 at 12.5(10) is unhelpful
+and as a minimum it would be useful if a short explanation
+was inserted here along the lines of that given in the
+Rationale.
+
+****************************************************************
+

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