I'm working with some code which frequently uses this … idiom I guess you'd call it?

use overload '""' => sub {shift->name;};

So I've read the Perldoc and it has this example: 

package Number;
use overload
   [snipped]
    '""' => sub { ...; };

[download]

which says it's "an anonymous subroutine to implement stringification: this is called whenever an object blessed into the package Number is used in a string context (this subroutine might, for example, return the number as a Roman numeral)."

So I guess, something like this?

### example package

package Number;

my $self = {};

sub new {
my $class = shift();
$self->{decimal} = shift();
return bless( $self, $class );
}

my @roman_numbers = qw[
  undef I II III IV V VI VII VIII IX X
];

use overload
  '""' => sub { return $roman_numbers[ $self->{decimal} ] };
1;

### main

package main;
my $instance = new Number(3);
print $instance;

### it will print 'III'

[download]

So, two questions:

  1. Why would I want this particularly?
  2. what's the specific thing in use in the code I'm seeing, use overload '""' => sub {shift->name;}; and why would I want that?

In reply to What's the point of this 'overload' idiom? by Cody Fendant

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