Thanks. The above test script passes all tests with the following definitions. The redundancy is annoying, but it'll do until I get around to making/finding a proper trait/extension. 

BEGIN {
   package Class;

   use strict;
   use warnings;

   use Moose;

   has val => (
      is       => 'rw',
      isa      => 'Num',
      required => 1,
   );


   use Moose::Util::TypeConstraints;

   coerce __PACKAGE__
      => from 'Num'
         => via { __PACKAGE__->new(val => $_) };

   subtype 'Maybe'.__PACKAGE__
      => as 'Maybe['.__PACKAGE__.']';

   coerce 'Maybe'.__PACKAGE__
      => from 'Num'
         => via { __PACKAGE__->new(val => $_) };
}


BEGIN {
   package Container;

   use strict;
   use warnings;

   use Moose;

   has always => (
      is      => 'rw',
      isa     => 'Class',
      coerce  => 1,
      default => sub { Class->new(val => 0) },
   );

   has maybe => (
      is      => 'rw',
      isa     => 'MaybeClass',
      coerce  => 1,
      default => undef,
   );
}

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In reply to Re^4: Moose type question by ikegami
in thread Moose type question by Sue D. Nymme

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