---
name: "Tie::RefHash"
section: "3pm"
platform: "linux"
package: "perl-5.004-doc"
version: "5.004.05-6"
release: "Debian 2.2 (Potato)"
platforms: ["linux"]
url: "https://new.carta.tech/Tie::RefHash/3pm"
---

# Tie::RefHash(3pm)

use references as hash keys

## NAME

Tie::RefHash - use references as hash keys

## SYNOPSIS

```
    require 5.004;
    use Tie::RefHash;
    tie HASHVARIABLE, 'Tie::RefHash', LIST;
```

```
    untie HASHVARIABLE;
```

## DESCRIPTION

This module provides the ability to use references as hash keys if you first `tie` the hash variable to this module.

It is implemented using the standard perl TIEHASH interface.  Please see the `tie` entry in [*perlfunc*(1)](/perlfunc/1.md) and [*perltie*(1)](/perltie/1.md) for more information.

## EXAMPLE

```
    use Tie::RefHash;
    tie %h, 'Tie::RefHash';
    $a = [];
    $b = {};
    $c = \*main;
    $d = \"gunk";
    $e = sub { 'foo' };
    %h = ($a => 1, $b => 2, $c => 3, $d => 4, $e => 5);
    $a->[0] = 'foo';
    $b->{foo} = 'bar';
    for (keys %h) {
       print ref($_), "\n";
    }
```

## AUTHOR

Gurusamy Sarathy        gsar@umich.edu

## VERSION

Version 1.2    15 Dec 1996

## SEE ALSO

[*perl*(1)](/perl/1.md), [*perlfunc*(1)](/perlfunc/1.md), [*perltie*(1)](/perltie/1.md)