To: J3                                                     10-222
From: John Reid
Subject: Interop TR: Requirement 1
Date: 2010 October 07
References: 10-165r2, ISO/IEC 1539-1:2010, N1820

DISCUSSION

Requirement 1 of N1820 is

     A mechanism should be provided to enable a C programmer to
     conveniently obtain the address of a particular element within an
     assumed-rank, assumed-shape, allocatable, or pointer array.

This can be done by adding an extra function. I have assumed that the
changes of 10-203r1 have been accepted so that the type CFI_index_t
is available.

EDITS to 10-165r2:

[11:3] Change "Eight" to "Six".

[11:9] Change the line to
"If an error occurs during execution of the function that returns an
int value, the returned value is".

[12:1-] Add new section:

5.2.6.1a void * CFI_address ( const CFI_cdesc_t *,
                              const CFI_index_t subscripts[] );

<<Description.>> CFI_address returns the address of the object described
by the C descriptor or an element of it. The object shall not be an
unallocated allocatable or a pointer that is not associated. The number
of elements in the subscripts array shall be greater than or equal to
the rank <r> of the object. If the object is an array, the result is the
address of the element of the object that the first <r> elements of the
subscripts array would specify if used as subscripts. If the object is
scalar, the result is its address and the subscripts array is ignored.