1 package Scalar::RefType;

     2 use strict;

     3 use warnings;

     4 use Carp;

     5 

     6 our $VERSION = '0.01';

     7 

     8 sub TIESCALAR {

     9     my ($class, $type) = @_;

    10     return bless { value => undef, type => ref $type ? ref $type : $type // '' };

    11 }

    12 

    13 sub FETCH { return $_[0]->{value} }

    14 

    15 sub STORE {

    16     my ($self, $value) = @_;

    17     my $ref = ref $value // '';

    18     if ($ref ne $self->{type}) {

    19 	croak 'invalid reference type';

    20     }

    21     return $self->{value} = $value;

    22 }

    23 

    24 __END__

    25 

    26 =head1 NAME

    27 

    28  Scalar::RefType - simple scalar type checker

    29 

    30 =head1 SYNOPSIS

    31 

    32  use Scalar::RefType;

    33 

    34  tie my $h1 => 'Scalar::RefType', {};

    35  tie my $h2 => 'Scalar::RefType', 'HASH';

    36 

    37  # dies:

    38  $h1 = [];

    39 

    40 =head1 DESCRIPTION

    41 

    42 This little module allows you to tie the type of a scalar to a specified

    43 reference type. If the refererence type of an assignment violetes the 

    44 tied type, the assignment throws an exception.

    45 

    46 =head1 AUTHOR

    47 

    48 Heiko Schlittermann <hs@schlittermann.de>

    49 

    50 =cut