To:        J3                                                J3/15-173
Subject:   Intrinsic that's either ASSOCIATED or ALLOCATED
From:      Van Snyder
Reference: 15-007r1
Date: 2015 June 07

1. Introduction
===============

I changed numerous components of numerous types from pointers to
allocatable.  I had to change all the references to ASSOCIATED to be
references to ALLOCATED.

One could write a family of generic functions, with each specific
function consisting of an invocation of either the ASSOCIATED or
ALLOCATED intrinsic function, but one would need a pair of specific
functions for every type, spectrum of kind type parameters, and rank.

An intrinsic function would be more convenient.

2. Proposal
===========

Provide an intrinsic function that has either the effect of one-argument
ASSOCIATED, or ALLOCATED, depending upon whether the actual argument has
the POINTER or ALLOCATABLE attribute.  The name proposed here is
AVAILABLE, but another name, such as USABLE, would be acceptable.

3. Edits
========

[326 Table 13.1] Add to Table 13.1, in alphabetical order:

"   AVAILABLE       ( A )       I   Allocation or association status of
                                    variable
"

[343:13+ 13.8.30+] Insert a subclause

"
13.8.30a  AVAILABLE ( A )

<<Description.>>  Whether a variable is allocated, associated, or
neither.

<<Class.>> Inquiry function.

<<Argument.>>  A shall be a variable that has either the ALLOCATABLE or
POINTER attribute.

<<Result Characteristics.>> Default logical.

<<Result Value.>>

Case (i):   If A has the ALLOCATABLE attribute, the result is true if
            the argument is allocated, and false otherwise.

Case (ii):  If A has the POINTER attribute, the result is true if the
            argument is associated with a target, and false otherwise.
            The association status shall not be undefined.
"