[Octave-bug-tracker] [bug #51962] ++ and -- not same as +1 and -1

[anonymous]

URL:
  <http://savannah.gnu.org/bugs/?51962>

                 Summary: ++ and -- not same as +1 and -1
                 Project: GNU Octave
            Submitted by: None
            Submitted on: Fri 08 Sep 2017 02:46:10 AM UTC
                Category: None
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: Unexpected Error
                  Status: None
             Assigned to: None
         Originator Name: 
        Originator Email: 
             Open/Closed: Open
         Discussion Lock: Any
                 Release: 4.2.1
        Operating System: Microsoft Windows

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Details:

A = a very large matrix.
# code here to build A
++A;

# run out of memory soon
whos
A    (large amount of memory)
ans  (same large amount of memory)

Enough memory for A but not both A and ans simultaneously.

BUT:

A = A+1; does not cause ans to become same as A.
Even A = A++; does not cause memory use to double.

Unexpected behavior because of side-effects in copying A to ans.

Side-effect behavior of ++ and -- may need to be changed to not update ans.




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