6 use Scalar::Util qw(readonly);
10 print "not " unless readonly(1);
15 print "not " if readonly($var);
18 print "not " unless $var == 2;
21 print "not " unless readonly("fred");
26 print "not " if readonly($var);
29 print "not " unless $var eq "fred";
34 print "not " if readonly($var);
37 print "not " unless readonly($$var);
40 print "not " if readonly(*STDOUT);