[J3] Self-assignment of allocatable component

[Daniel C Chen]

Hi Vipul,

My understanding is that the paragraph you quoted is AFTER (1), deallocate
LHS component, and (2), allocate LHS component based on RHS. Because Step
(1) already makes the RHS component unallocated, the rest actions are void.

Thanks,

Daniel Chen

XL Fortran Development, Fortran Standard Representative
IBM Toronto Software Lab
Phone: 905-413-3056
Tie: 969-3056
Email: cdchen at ca.ibm.com



From:	"Vipul Parekh via J3" <j3 at mailman.j3-fortran.org>
To:	"General J3 interest list" <j3 at mailman.j3-fortran.org>
Cc:	"Vipul Parekh" <parekhvs at gmail.com>
Date:	2021-07-26 04:10 PM
Subject:	[EXTERNAL] Re: [J3] Self-assignment of allocatable component
Sent by:	"J3" <j3-bounces at mailman.j3-fortran.org>



On Mon, Jul 26, 2021 at 3:17 PM Daniel C Chen via J3
<j3 at mailman.j3-fortran.org> wrote: .. Apprently p%i is unallocated after
the self-assignment. Is this code still standard conforming? Hi Daniel,
Interesting question!  3 different compilers 


On Mon, Jul 26, 2021 at 3:17 PM Daniel C Chen via J3 <
j3 at mailman.j3-fortran.org> wrote:
  ..


  Apprently p%i is unallocated after the self-assignment. Is this code
  still standard conforming?

Hi Daniel,

Interesting question!  3 different compilers I have access to indicate
"p%i" is indeed allocated after the "self-assignment"!

I look forward to the discussion.  Paragraph 1 in section 10.2.1.3
Interpretation of intrinsic assignments [p170:11-16] reads as the
assignment you show can be interpreted *as though* it were *equivalent* to:
   block
      type(dt) :: tmp
      tmp = p
      p = tmp
   end block

thereby leaving "p%i" as allocated and which is what the 3 processors I
tried appeared to be doing.

Regards,
Vipul Parekh

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