CVS difference for ai05s/ai05-0214-1.txt

--- ai05s/ai05-0214-1.txt	2010/06/13 04:24:42	1.1
+++ ai05s/ai05-0214-1.txt	2010/08/05 02:05:42	1.2
@@ -1,7 +1,5 @@
-!standard  3.3.1(9/2)                                10-06-12  AI05-0214-1/01
-!standard  3.7(9.1/2)
-!standard  4.8(6/3)
-!standard  6.5(5.9/3)
+!standard  3.7(9.1/2)                                10-08-04  AI05-0214-1/02
+!standard  3.7.2(3)
 !class amendment 10-06-12
 !status work item 10-06-12
 !status received 10-06-12
@@ -28,7 +26,7 @@
 that doesn't use priorities); in that case, having to explicitly provide
 a priority is a nuisance.
 
-This limitation such be eliminated.
+This limitation should be eliminated.
 
 !proposal
 
@@ -36,39 +34,23 @@
 
 !wording
 
-Modify 3.3.1(9/2):
-
-    If a composite object declared by an object_declaration has an
-    unconstrained nominal subtype, then if this subtype is indefinite{,
-    is nonformal limited tagged} or the
-    object is constant the actual subtype of this object
-    is constrained. The constraint is determined by the bounds or discriminants
-    (if any) of its initial value; the object
-    is said to be constrained by its initial value.  ...
-
 Modify 3.7(9.1/2):
 
     No default_expressions are permitted in a known_discriminant_part in a
     declaration of a {nonlimited} tagged type [or a generic formal type].
-
-Modify 4.8(6/3): (As modified by AI05-0041-1)
-
-    If the designated type of the type of the allocator is elementary, then
-    the subtype of the created object is the designated subtype. If the
-    designated type is composite, then the subtype of the created object is
-    the designated subtype when the designated subtype is constrained {or
-    nonformal limited tagged} or there is an ancestor of the designated
-    type that has a constrained a partial view of the designated type that
-    is constrained; otherwise, the created always constrained; if the
-    designated subtype is constrained, then it provides the constraint
-    of the created object; otherwise, the object is constrained by its
-    initial value [(even if the designated subtype is unconstrained with
-    defaults)].
 
-Modify 6.5(5.9/3): (As modified by AI05-0032-1)
+Modify 3.7.2(3):
 
-    ...  If the nominal subtype is indefinite {or nonformal limited tagged},
-    the return object is constrained by its initial value. ...
+A'Constrained
+    Yields the value True if A denotes a constant, a value, [or] a constrained
+    variable{, or a tagged object}, and False otherwise.
+
+AARM Reason: Tagged objects always are considered constrained by this attribute
+to avoid distributed overhead for parameters of limited classwide types, as
+limited tagged objects may technically be unconstrained if they use defaulted
+discriminants. Such objects still cannot have their discriminants changed, as
+assignment is not supported for them, so there is no use for this attribute
+that would justify the overhead of passing it with all classwide parameters.
 
 !discussion
 
@@ -85,11 +67,11 @@
 and thus the value of 'Constrained would have to be passed with the parameter.
 Since 'Constrained is not useful for limited types, this is pointless.
 
-Thus we define objects of nonformal limited tagged types to be constrained
-by their initial value. (We don't use "immutably limited" as that would be
-incompatible -- changing the value of 'Constrained in useless changes -- and
-it does not cover all limited tagged types [although we may decide to fix
-that.]
+Thus we 'Constrained to be True for all tagged objects, regardless of the form of
+their discriminants. We considered a more consistent rule which would 
+define objects of nonformal limited tagged types to be constrained
+by their initial value, but it required too many wording changes for a "simple"
+change.
 
 !example
 
@@ -396,31 +378,6 @@
 
 I don't think this change would have any effect one way or the other on the
 implementation of build-in-place, but that's ok.
-
-****************************************************************
-
-From: Bob Duff
-Date: Friday, May 21, 2010  1:29 PM
-
-****************************************************************
-
-From: Bob Duff
-Date: Friday, May 21, 2010  1:29 PM
-
-****************************************************************
-
-From: Bob Duff
-Date: Friday, May 21, 2010  1:29 PM
-
-****************************************************************
-
-From: Bob Duff
-Date: Friday, May 21, 2010  1:29 PM
-
-****************************************************************
-
-From: Bob Duff
-Date: Friday, May 21, 2010  1:29 PM
 
 ****************************************************************