Monks,

I recently discovered i bug in my code. My intention was to create a hash reference with a key for each value of an array reference.

use strict;
use warnings;
use diagnostics;

my $arr = [1,2,3];
my $hr  = undef;

map { $hr->{$_} } @{$arr};
[download]

The last line should have been written as

map { $hr->{$_} = 1 } @{$arr};
[download]

Could this bug have been picked up by some sibling of use warnings ?