If I try running the following:

#!/usr/bin/perl -w

use Data::Dumper;

{
  my $hashref;
  $hashref->{'foo'} = "bar";

  print Dumper($hashref);
}
[download]

then I get the expected result:

[alex@home dev]$ perl -w hashref.pl 
$VAR1 = {
          'foo' => 'bar'
        };
[download]

However, if I try to combined the my and the assignment on the same line, as in the following:

#!/usr/bin/perl -w

use Data::Dumper;

{
  my $hashref->{'foo'} = "bar";

  print Dumper($hashref);
}
[download]

then Perl gives me an error:

[alex@home dev]$ perl -w hashref2.pl
Can't use an undefined value as a HASH reference at hashref2.pl line 6
+.
[download]

This seems odd to me -- does this mean that there's a limit to what autovivification will do?

The difference seems semantic to me. Please, pass me a clue by four.

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