There's also a Tie::RefHash::Weak on CPAN. (The core module Tie::RefHash treats keys as strong references.)

use Moops; class Cow :rw { has name => (default => 'Ermintrude') }; say Cow->new->name

In reply to Re^2: Use a hashref as a key in another hashref? by tobyink
in thread Use a hashref as a key in another hashref? by mwb613

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