If I try and use the following piece of code: 

#!/usr/bin/perl -w

use strict;
use diagnostics;

use Tie::RegexpHash;

my $rehash = Tie::RegexpHash->new();

$rehash->add( qr/abc/, "abc" );
$rehash->add( qr/def/, "def" );

[download]

I get the following warning: 

Use of uninitialized value in string ne at
        /usr/local/lib/perl5/site_perl/5.8.0/Tie/RegexpHash.pm line 58
+ (#1)
    (W uninitialized) An undefined value was used as if it were alread
+y
    defined.  It was interpreted as a "" or a 0, but maybe it was a mi
+stake.
    To suppress this warning assign a defined value to your variables.

    To help you figure out what was undefined, perl tells you what ope
+ration
    you used the undefined value in.  Note, however, that perl optimiz
+es your
    program and the operation displayed in the warning may not necessa
+rily
    appear literally in your program.  For example, "that $foo" is
    usually optimized into "that " . $foo, and the warning will refer 
+to
    the concatenation (.) operator, even though there is no . in your
    program.

[download]

Can anyone suggest what might be happening?
Thanks

Edit by tye to remove "cpan://" as noted by author

In reply to Problem with Tie::RegexpHash by sch

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