#!/usr/bin/perl -w

use strict;
use IO::File;

my %in;  my %out;
$in{b} = new IO::File; $out{b} = new IO::File;
$in{b}->open("<ramdata") || die $!;
$out{b}->open(">ramdata2") || die $!;
my $fi = $in{b}; my $fo = $out{b};

&v1;
# &v2; # this also works

close($in{b});  close($fo);

sub v1 {                     # works 
 while (<$fi>) { 
   print $fo "-> $_"; 
 }
}

sub v2 {                     # works
 my $x = $in{b};
 while (<$x>) { 
   print {$out{b}} "-> $_";  # sneak by print: treat as object
 }
}

sub nogoods {                # these doesn't compile
# while (<{$in{b}}>) {       # no obj allowed in diamond
# ... }
# while (readline($in{b})) { # bad: storing obj not fh glob
# ... }
}