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Date: Mon, 08 Dec 2008 22:02:21 +0100
From: Reinhold Bader <Reinhold.Bader@lrz.de>
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Subject: Re: (j3.2006) (SC22WG5.3769)    Response on the TR29113 draft N1761
References: <20081207203535.92039C178D6@www2.open-std.org>	<20081208171349.2CAD1C178E4@www2.open-std.org>	<20081208184041.89C0DC178E4@www2.open-std.org> <20081208190353.C4B27C178DC@www2.open-std.org>
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Craig Rasmussen schrieb:
> On Dec 8, 2008, at 11:40 AM, Reinhold Bader wrote:
> 
>>
>> Bill Long schrieb:
>>> Reinhold Bader wrote:
>>>
>> Note that the
>>> main purpose of adding this feature was for MPI-like interfaces,  
>>> where
>>> the only objective was to pass the object to a C function and give  
>>> the
>>> function tools to correctly interpret the object.
>> Yes. Note that I'm not yet sure the MPI Forum is going to swallow  
>> this since
>> the MPI vendors apparently don't want to rewrite their whole  
>> infrastructure to use
>> descriptors ... even though it provides the technically better  
>> solution.
> 
> Since the MPI vendors will have to write wrappers for the MPI  
> functions, there is no real technical problem for them and I don't  
> think they will complain too loudly (I will ask at the MPI Forum next  
> week).  The main requirement is that existing _users code_ won't need  
> to change.  

I understand descriptors are out for these since assumed shape
actuals cannot be handed over.

> The way the TR is currently written, I think the MPI 3.0  
> Fortran interfaces won't use assumed shape dummy variables and so  
> vendors won't need to access descriptors.

Issue 4 from my comments contends that it is not possible to
fulfill the main requirement above with the current TR.

> 
> Regards,
> Craig
> 

Regards
Reinhold