(j3.2006) (SC22WG5.4648) [ukfortran] AW: Vote on N1904

[Bill Long]

On 3/14/12 5:57 PM, N.M. Maclaren wrote:
> On Mar 14 2012, Bader, Reinhold wrote:
>>
>> Rolf may be able to shed more light on this, so am putting him on CC
>> here.
>> In any case, it is not the purpose of MPI-3 to enable communication of
>> data of types described below, so while I'm not convinced that loosening
>> of the planned INTENT(OUT) prohibition is necessary, the below would
>> certainly not impact MPI-3.
>
> No, that wasn't my point.
>
> It was that MPI receive buffers are a well-known example of where
> output-only assumed-type arguments are needed. While there is no
> difficulty in using INTENT(INOUT) or no INTENT, having to specify
> something other than what you intend is poor software engineering.
>

I appreciate the principle.  However, one might argue that declaring a 
variable TYPE(*) already has you pretty far down the "poor software 
engineering" road.

> There is no reasonable sense in which assumed-type is incompatible
> with INTENT(OUT) as such. The only incompatibility is with some of
> the semantic requirements that have been attached to INTENT(OUT) for
> some types.
>

True. I assume your proposed exceptions were intended to added to 6.3p2. 
  The risk I see is that we miss something, or spend undue time haggling 
over the wording. The risk/reward balance is the concern.  In contrast, 
Reinhold's proposed edit (add INTENT(OUT) to the list in C4071) is very 
simple -> low risk.   I agree it is overkill, but for such a narrowly 
focused feature as TYPE(*), I think that is an acceptable trade-off.

Cheers,
Bill


>
> Regards,
> Nick Maclaren.
>
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-- 
Bill Long                                           longb at cray.com
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