08-308r1

To:        J3
From:      Malcolm Cohen
Subject:   Cross-image referencing and polymorphism
Date:      2008 November 21
Reference: 08-199r1, 08-267, 08-301r1.

1. Introduction

This paper handles the problems raised in 08-199r1 and 08-267.  The
analysis was similar to that in paper 08-301r1.  We have chosen to make a
similar limitation; basically, a whole polymorphic subobject of a coindexed
object is only allowed in certain situations; this reduces the
implementation cost.

The edits supplied subsume the second edit in 08-301r1.

The second edit is needed to prevent the "polymorphic allocatable
subcomponent" situation from arising when both the actual argument and the
dummy argument are polymorphic (if that is the case, the extent of the
copying cannot be determined at compile time).


2. Edits:

[117:6.4.2 C616+] Insert new constraint
  "C616a (R611) Except as an actual argument to an intrinsic inquiry
         function or as the <designator> in a type parameter inquiry, a
         <data-ref> shall not be a polymorphic subobject of a coindexed
         object and shall not have a polymorphic allocatable subcomponent."

[289:12.5.2.4p6] Append to paragraph
  "If the actual argument is a polymorphic coindexed object, the dummy
   argument shall not be polymorphic."

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