types-type_math-bigfloat.pl

package My::Types;

use strict;
use warnings;
use Type::Utils;
use Type::Library -base,
                  -declare => 'Percentage';
use Types::Standard qw(Num);
use Math::BigFloat;

declare Percentage,
  as class_type({ class => 'Math::BigFloat' }),
#  where { $_ >= 0 && $_ <= 1 };
  where { 1 };

#coerce Percentage,
#  from Num,
#  via { Math::BigFloat->new($_) };

package My::Class;

use Moo;

has foo => (
    is => 'rw',
    isa => My::Types::Percentage,
    coerce => My::Types::Percentage->coercion,
    required => 1
);

package main;

use strict;
use warnings;

My::Class->new( foo => Math::BigFloat->new(0.5) );