J3/10-212
To: J3
From: Malcolm Cohen
Subject: Interp: VALUE attribute restrictions.
Date: 2010 September 26

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NUMBER: F08/?
TITLE: VALUE attribute restrictions.
KEYWORDS: VALUE
DEFECT TYPE: Erratum
STATUS: J3 consideration in progress

QUESTION:

Consider the program unit

  SUBROUTINE s(x,y,n)
    REAL,VALUE :: x(:)
    CHARACTER(n),VALUE :: y
    DO i=2,SIZE(x)
      x(i) = x(i) + x(i-1)
    END DO
    PRINT *,y,x
  END SUBROUTINE

This is not valid in Fortran 2003 as it violates constraint C527
  "If the VALUE attribute is specified, the ... DIMENSION
   ... attribute shall not be specified."
and also violates constraint C528
  "If the VALUE attribute is specified, the length type parameter
   values shall be omitted or specified by initialization
   expressions."

The corresponding constraint to F2003/C527 for Fortran 2008, C558,
does not prohibit the DIMENSION attribute.  There does not appear to
be any constraint in F2008 corresponding to F2003/C528.  Therefore
this program unit is apparently now syntactically correct.

However, the Introduction to the Fortran 2008 standard does not
mention these as new features.

Is the omission of these requirements an oversight?

ANSWER:

No, these are deliberate additions to the language.  An edit is
supplied to clarify the Introduction.

EDITS:

{to 10-007}

[xiii] Introduction, bullet "Data declaration", append
  "The VALUE attribute is permitted for an array, and for an object
   with a nonconstant length type parameter."

SUBMITTED BY: Malcolm Cohen

HISTORY: 10-212   m193 Submitted

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