in reply to Re^7: Why does exists cause autovivication?
in thread Why does exists cause autovivication?

Okay, so is my original example: 
next unless exists $user_by_uid{$uid}->{$host};

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more like the following: 

$href = defined $user_by_uid{$uid} ? $user_by_uid{$uid} : {}; #Fake au
+toviv
next unless exists $href->{$host};

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Or would it be more like the following, using your example code? 

next unless my_fake_exists $user_by_uid{$uid}, $host;

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In other words, since there is no short-circuit evaluation to avoid the -> in my original example does that mean the autoviv occurs before anything is passed in to 'exists'?

Thanks very much for taking time to respond and hope you had a Happy New Year!!

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Re^9: Why does exists cause autovivication?
by shmem (Chancellor) on Jan 02, 2008 at 21:31 UTC
    No need to autovivify anything, only to test an empty hashref for a non-existent key. 
    next unless exists $user_by_uid{$uid};
next unless exists $user_by_uid{$uid}->{$host};

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    should do.

    --shmem 

    _($_=" "x(1<<5)."?\n".q·/)Oo.  G°\        /
                              /\_¯/(q    /
----------------------------  \__(m.====·.(_("always off the crowd"))."·
");sub _{s./.($e="'Itrs `mnsgdq Gdbj O`qkdq")=~y/"-y/#-z/;$e.e && print}
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[d/l]

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