While reading up on the documentation of base, I came across a reference for fields. What is this module, and can anyone comment on how they've used it effectively, or is it just some sort of experiment that somehow ended up in the base distribution?

Since the links above are probably pointed off into deep space, here's an excerpt from the POD:
DESCRIPTION
The "fields" pragma enables compile-time verified class fields. 
     # subclassing
     {
         package Bar;
         use base 'Foo';
         use fields qw(baz _Bar_private);        # not shared with Foo
         sub new {
             my $class = shift;
             my $self = fields::new($class);
             $self->SUPER::new();                # init base fields
             $self->{baz} = 10;                  # init own fields
             $self->{_Bar_private} = "this is Bar's secret";
             return $self;
         }
     }

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In reply to use fields by tadman

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