I'm wondering about the behaviour of the following:
use Scalar::Util qw(readonly);;

my %hash = ( A => 1 );

while ( my ( $abc, $num ) = each %hash ) {
  print "$abc\n";
  print "$abc is readonly\n" if readonly($abc);
  my $bar = $abc;
  print "bar is readonly\n" if readonly($bar);
  foo($abc);
  print "$abc is still readonly\n" if readonly($abc);
}

sub foo {
  $_[0] .= 'FOO';
}

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This prints (on perl 5.14.1):
A
A is readonly
bar is readonly

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First, I don't expect $abc to be read-only, as it is not an alias for the hash key, but if it is readonly, then the call to foo() should not work, we should get a "modification of a readonly value" error. And why is $bar read-only? It's just a copy of the value in $abc. Or has this changed in recent versions of perl?

In reply to Readonly problems by runrig

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