J3/04-344

To:      J3
From:    Dan Nagle
Subject: C_SIZEOF
Date:    2004 June 24

One item of unfinished business from f03 is the issue
of a storage size intrinsic returning the C language idea
of storage size.  This is due, mainly, to the ubiquitous nature,
in C, of procedure calls with <address-of-thingo>, <sizeof-thingo>
pairs.

Number:

Title: C_SIZEOF

Submitted By: J3

Status: For Consideration

References:

Basic Functionality: Add a procedure to ISO_C_BINDING
                     to return the size of its argument as per C sizeof.

Rationale:  There are situations where a program needs to know
            the size of an entity, as expressed in C.

Estimated Impact: The impact was estimated by J3 at 167 as Small.

Detailed Specification: A procedure to return the size
                        of its argument as per C.

                       Edits:

                       [125:41+] Add list item

                       "(4++) the intrinsic module function C_SIZEOF,"

                       [395:31+++] (after the Note) Add section

                       "15.1.2.6 C_SIZEOF (X)

                       *Description.*  Returns the size, as defined
                                       by the C sizeof operator (Section
                                       6.5.3.4 of the C International Standard),
                                       of the argument X.

                       *Class.*  Inquiry function.

                       *Arguments.*

                       X               may be of intrinsic or derived type.  It
                                       shall not be polymorphic.  If it is
                                       of derived type, that type shall be
                                       a SEQUENCE or interoperable type and
                                       shall have no allocatable ultimate
                                       components.  If its type has
                                       any deferred type parameters, it shall
                                       be a pointer that is associated or
                                       an allocatable object that is
                                       allocated.  It may be a scalar
                                       or an array that is not assumed-size.

                       *Result Characteristics.*  Integer scalar
                                                  of kind C_SIZE_T (15.2.1).

                       *Result Value.*  The result value is the size of X
                                        as defined by the sizeof operator (Section
                                        6.5.3.4 of the C International Standard)
                                        of the companion C processor.  If
                                        the companion processor is not a C processor,
                                        the result value is processor dependent."

History: Submitted as 04-121 at 167.