CVS difference for ais/ai-00167.txt
--- ais/ai-00167.txt 2003/05/24 00:51:33 1.8
+++ ais/ai-00167.txt 2003/06/07 04:58:54 1.9
@@ -569,4 +569,60 @@
****************************************************************
+From: Pascal Leroy
+Date: Thursday, April 24, 2003 10:55 AM
+
+AI 167 singles out assignment_statements and object_declarations as
+constructs that can be used to store the value returned by
+Unchecked_Conversion before testing for validity. As part of his
+editorial review, Kiyoshi commented:
+
+"Is the special case handling limited to 'an assignment_statement or an
+object declaration'? For example, in AI-00287, similar special case
+consideration is given also to default_expression, allocator, and formal
+object declaration. I agree that assignment_statement and object
+declaration cover most of useful cases, but like to make the situation
+clear."
+
+I think that parameter passing should be excluded here, or we are
+killing all optimizations. So default_expressions for parameters ought
+to be excluded too. However, I am not sure what the right answer is for
+the other constructs. Surely at the Padua meeting we didn't look at all
+the constructs that involve an assignment operation, so I am wondering
+if we covered all the useful cases.
+
+****************************************************************
+
+From: Tucker Taft
+Date: Thursday, April 24, 2003 11:59 AM
+
+This seems like a case where we should err on the
+side of limitation, namely, only allow the minimal
+number of constructs we think are needed.
+Assignment statements and object declarations
+are sufficient. No need to explore other obscure
+alternatives in my view. But for the record...
+
+ generic formal -- bad idea for shared generics
+ (equivalent to subprogram parameter in that case)
+ parameter/default -- bad, since subprogram body doesn't
+ "see" the unchecked conversion
+ allocator -- obscure
+ aggregate -- obscure
+
+****************************************************************
+
+From: Tucker Taft
+Date: Thursday, April 24, 2003 12:29 PM
+
+I agree, no need to include other constructs.
+
+****************************************************************
+
+From: Robert Dewar
+Date: Friday, April 25, 2003 7:53 AM
+
+I agree with this limitation.
+
+****************************************************************
Questions? Ask the ACAA Technical Agent