Maybe something along the lines of:

around BUILDARGS => sub {
  my $orig   = shift;
  my $self   = shift;
  my $params = $self->$orig(@_);
  $params->{$_} || delete $params->{$_}
    for qw/ foo bar /;
  return $params;
};

[download]

This will discard false parameters for the "foo" and "bar" attributes.

package Cow { use Moo; has name => (is => 'lazy', default => sub { 'Mooington' }) } say Cow->new->name

In reply to Re^6: Moose and default values by tobyink
in thread Moose and default values by morgon

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