To: J3                                                          11-249r1
From: Van Snyder
Subject: DIN1: edits to PDTR 29113
Date: 2011 October 12
Reference: WG5/N1869, WG5/N1882

Discussion from DIN 1
---------------------

Allowing the ALLOCATABLE or POINTER attribute for assumed-rank entities
might cause a problem within Fortran in case a future extension is
considered, which would allow entities to change rank at run time
("deferred-rank"). In this case, it would be preferable for a
declaration

    REAL, DIMENSION(..), ALLOCATABLE :: X

to denote a deferred-rank entity. Alternatively, a mechanism would be
required (within Fortran) to disambiguate deferred-rank from
assumed-rank entities during execution of the program.

Therefore it is suggested that, until the Fortran facilities are
properly defined, the ALLOCATABLE and POINTER attributes be
prohibited for assumed-rank entities.

Response from PL22.3
--------------------

The potential future benefit of deferred-rank entities is less than the
current benefit of assumed-rank pointer and allocatable entities.

Therefore PL22.3 chooses not to make the change requested in the first
comment from DIN.

If deferred-rank entities are found to be desirable in the future, a
syntax different from the syntax for assumed-rank entities can be
developed.