use Devel::Peek;
use strict;
no warnings "numeric";

sub xx {
        my $arg = shift;
        my $const = "";
        print "(" . ($arg & $const) . ")\n";
}

xx("ff");
xx(7);
xx("ff");

##</code><code>##

SV = PV(0x100802558) at 0x1008474e0
  REFCNT = 1
  FLAGS = (PADMY,POK,pPOK)
  PV = 0x1002074f0 "ff"\0
  CUR = 2
  LEN = 8
()
SV = PVIV(0x100803c58) at 0x1008474e0
  REFCNT = 1
  FLAGS = (PADMY,IOK,pIOK)
  IV = 7
  PV = 0x1002074f0 "ff"\0
  CUR = 2
  LEN = 8
(0)
SV = PVIV(0x100803c58) at 0x1008474e0
  REFCNT = 1
  FLAGS = (PADMY,POK,pPOK)
  IV = 7
  PV = 0x1002074f0 "ff"\0
  CUR = 2
  LEN = 8
()