[MPI3 Fortran] Summary of items on the table

Bill Long longb at cray.com
Mon Apr 28 15:29:04 CDT 2008

Aleksandar Donev wrote:
> On Monday 28 April 2008 12:51, Bill Long wrote:
>> Changing the actual argument to a C_LOC reference also has the side
>> effect of making the actual argument an expression whose value is not a
>> Fortran pointer.  Thus, the corresponding dummy argument cannot be
>> defined.  A problem for about half of the interesting MPI cases.
> That's a bogus complaint. The actual is a C pointer, and cannot be changed, 
> indeed. But its target can be changed through the pointer, which is exactly 
> the intent here.

The problem is that the Fortran standard supports those semantics only 
for a Fortran pointer, not for a C pointer.  I know it "will work 
anyway",  but that does not mean it is valid.


> I'll give my "vote" when I have a little more time to think about it...
> Best,
> Aleks

Bill Long                                   longb at cray.com
Fortran Technical Support    &              voice: 651-605-9024
Bioinformatics Software Development         fax:   651-605-9142
Cray Inc., 1340 Mendota Heights Rd., Mendota Heights, MN, 55120


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