I have come across an interesting problem: 
perldoc -f exists

    undef $ref;
    if (exists $ref->{"Some key"})      { }
    print $ref;             # prints HASH(0x80d3d5c)

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The documentation goes further to say: 
  This surprising autovivification in what does not at first--or
  even second--glance appear to be an lvalue context may be fixed
  in a future release.

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Normally I would not care that perl is creating keys in deeply nested hashes so long as I know that the value is undef, but if I grab a list of keys without thinking: 
C:\>perl -e "undef $ref; if (exists $ref->{'key1'}->{'key2'})
{print 'I think i am okay, but...'}; print keys %{$ref}"
key1

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So, is there a module out there that will control the way perl autovivifies (kind of like AutoLoader but for variables) nested structures?

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In reply to Autovivify Module? by InfiniteSilence

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