#!/usr/bin/perl
use warnings;
use strict;
use feature qw{ say };

use builtin qw{ stringify };
use Devel::Peek qw{ Dump };

my $v = 100;
for (sub { scalar shift }, sub { stringify shift }) {
    $_->($v);
    Dump $v;
}

##</code><code>##

Built-in function 'builtin::stringify' is experimental at 2.pl line 10.
SV = IV(0xf57500) at 0xf57510
  REFCNT = 1
  FLAGS = (IOK,pIOK)
  IV = 100
SV = PVIV(0xf20db0) at 0xf57510
  REFCNT = 1
  FLAGS = (IOK,pIOK,pPOK)
  IV = 100
  PV = 0xf09d20 "100"\0
  CUR = 3
  LEN = 16