(j3.2006) question about generic resolution

[Aleksandar Donev]

On Tuesday 23 March 2010, Malcolm Cohen wrote:

> The "POINTER vs ALLOCATABLE" generic feature is fundamentally
> misguided.
I do not agree with this statement---this feature does have uses, and 
this has been debated in WG5, which voted to put it on the list. No need 
to revisit this just because Malcom disagrees with this decision.

I do agree that now is not the time to get into a "priority" selection 
scheme for generic resolution, even if we are only talking about single 
casing this particular problem. Generics should be inambiguous, and the 
original POINTER vs. ALLOCATABLE proposal, which predates the "pointer 
dummy target actual" feature, was (thought to be) inambiguous and thus 
OK.

The "pointer dummy target actual" feature, which seems to cause a direct 
collision here, was added later, perhaps without sufficient review, as a 
response to a request by myself for some form of (guaranteed) copyless 
argument association. It seems a cool feature, but I am not sure how 
much use there is to it, especially considering that it can be done 
"manually" by constructing a local pointer and pointing it to the actual 
and then passing that on.

I do not like this "remove features because we found a collision and 
someone thinks they are useless". We debated these features and in this 
case, if anything, it is the other feature that is less useful.

That said, I am not yet certain how to solve this in the "best" possible 
manner... I just know what I do not want to do :-)

Best,
Aleks

-- 
Aleksandar Donev, Ph.D.
Luis W. Alvarez Postdoctoral Fellow
Center for Computational Sciences and Engineering (https://ccse.lbl.gov)
Lawrence Berkeley National Laboratory (http://www.lbl.gov)
E-mail: adonev at lbl.gov
Phone: (510) 486-5782  Fax: (510) 486-6900
Address: MS 50A-1148, LBL, 1 Cyclotron Rd., Berkeley, CA 94720
Web: http://cims.nyu.edu/~donev/