use Tie::Constrained;

tie my $array_ref,
    'Tie::Constrained', sub { ref $_[0] eq 'ARRAY' };

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After that, an attempt to assign anything but an unblessed array ref will fail. Continuing, 
tie my $hash_ref,
    'Tie::Constrained', sub { ref $_[0] eq 'HASH' };

tie my $scalar_ref,
    'Tie::Constrained', sub { ref $_[0] eq 'SCALAR' };

tie my $scalar_value,
    'Tie::Constrained', sub { not ref $_[0] };

tie my $query,
    'Tie::Constrained',
    sub { ref $_[0] and $_[0]->isa('CGI') },
    CGI->new;

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There are all kinds of possibilities.

After Compline,
Zaxo

In reply to Re: Strict to references of a particular Variable of particular type. by Zaxo
in thread Strict to references of a particular Variable of particular type. by jesuashok

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