use strict;
use warnings;

sub printref {
    print ${$_[0]};
}

my $foo = "abc";
my $fooref = \$foo;       # Referenz auf $foo

printref($fooref);        # liefert "abc"
printref("$fooref");      # liefert Warnung "Can't use string ("SCALAR(0x12345678)") 
                           # as a SCALAR ref while "strict refs" in use at ..."