J3/14-237
To:        J3
From:      Van Snyder
Subject:   Purity of procedures in ISO_C_Binding
Date: 2014 September 26
Reference: 14-007r2

1. Discussion
=============

There appears to be no reason that the procedures in ISO_C_Binding are
not pure.  Subclause 13.1p1 specifies that all standard intrinsic
functions are pure, but functions in intrinsic modules are not standard
intrinsic functions.  There is no specification that intrinsic
subroutines are pure (because some of them are not).  Subclause 13.8.1
specifies that the procedures in ISO_Fortran_ENV, described in 13.8.2,
are pure.  Subclause 14.11.1 specifies that functions in IEEE_Arithmetic
are pure.  Table 14.1 in subclause 14.10 specifies which subroutines in
IEEE_Arithmetic are pure.  There is no corresponding specification in
clause 15.

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

Specify that procedures in ISO_C_Binding are pure.

3. Edits
========

[444:19 15.2.3.1p1] Append a sentence: "All procedures in the
module are pure."