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Message-ID: <4C52F1A5.5040109@courant.nyu.edu>
Date: Fri, 30 Jul 2010 08:37:09 -0700
From: Aleksandar Donev <aleks.donev@gmail.com>
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To: J3 <j3@j3-fortran.org>, SC22WG5 <sc22wg5@open-std.org>
Subject: Re: (j3.2006) (SC22WG5.4305) Executing a type-bound procedure on
 a coindexed object
References: <20100729154103.E2BD3C3BA01@www2.open-std.org> <4C51AC7D.2000805@lrz.de>
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Reinhold Bader wrote:
>  This does not seem to make sense. The case you mention can also happen
>   in a non-polymorphic scenario, but there are no restrictions there.
Which is a hint that the size of the allocatable components is not the 
issue. There are restrictions to ensure that the sizes match so that 
remote reallocation never happens. The issue, as I recall, was that 
there could be other components of unknown types, shapes, etc. In a 
heterogeneous environment, copying such things may be harder than just 
getting an integer size of an allocatable array.
In general, it is likely it is all implementable even without some of 
the restrictions, but someone asked to add a restriction to facilitate 
implementation, and we listened unless it took away what was seen as a 
critical functionality. Polymorphic coarrays were not in general seen as 
"critical" :-)
Best,
Aleks

-- 
Aleksandar Donev
Assistant Professor of Mathematics
Courant Institute of Mathematical Sciences, New York University
E-mail: donev@courant.nyu.edu
Phone: (510) 910-0891
Address: 251 Mercer St, New York, NY 10012
Web: http://cims.nyu.edu/~donev/