$rv = \$var;           # reference to $var
$str = "".\$var;       # STRING value of $rv
                       # ($str could conceivably occur in your
                       # program "by chance")

ref $rv or die;        # ASSERT: $rv is a reference
!(ref $str) or die;    # ASSERT: $str is NOT a reference

print $rv eq $str, $/; # Prints "1": a reference equals a string.