:D You're not paying attention 
$ perl -MDDS -w -le " my $hr; $hr->{stuff}; Dump($hr)"
$HASH1 = {};

$ perl -MDDS -Mwarnings -le " my $hr; $hr->{stuff}; Dump($hr)"
Useless use of hash element in void context at -e line 1.
$HASH1 = {};

[download]
$hr used to be undef, after $hr->{stuff} it is a hashref.

Curiously, my little test reveals Data::Dump::Streamer breaks the -w switch .

In reply to Re^5: Possible useless use of map by Anonymous Monk
in thread Possible useless use of map by andreas1234567

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