use feature qw( state );
   use Type::Params qw( compile );
   use Types::Standard qw( Num );
   
   sub add_numbers {
      state $signature = compile( Num, Num );
      my ( $x, $y ) = $signature->( @_ );
      
      return $x + $y;
   }

##</code><code>##

   use feature qw( state );
   use Type::Params qw( compile_named_oo );
   use Types::Standard qw( Num );
   
   sub add_numbers {
      state $signature = compile_named_oo(
         { head => [ Any ] },
         'x' => Num,
         'y' => Num,
      );
      my ( $self, $arg ) = $signature->( @_ );
      
      return $arg->x + $arg->y;
   }

##</code><code>##

   use feature qw( state );
   use Type::Params qw( signature );
   use Types::Standard qw( Num );
   
   sub add_numbers {
      state $signature = signature(
         method     => 0,
         positional => [ Num, Num ],
      );
      my ( $x, $y ) = $signature->( @_ );
      
      return $x + $y;
   }

##</code><code>##

   use feature qw( state );
   use Type::Params qw( signature );
   use Types::Standard qw( Num );
   
   sub add_numbers {
      state $signature = signature(
         method     => 1,
         named      => [ 'x' => Num, 'y' => Num ],
      );
      my ( $self, $arg ) = $signature->( @_ );
      
      return $arg->x + $arg->y;
   }

##</code><code>##

   use experimental qw( signatures );
   use Type::Params qw( signature_for );
   use Types::Standard qw( Num );
   
   signature_for add_numbers => (
      method     => 1,
      named      => [ 'x' => Num, 'y' => Num ],
   );
   
   sub add_numbers ( $self, $arg ) {
      return $arg->x + $arg->y;
   }

##</code><code>##

   use Type::Tiny::Enum Size => [ qw( S M L XL ) ];

##</code><code>##

   package Local::TShirt {
      use Moose;
      use Types::Common -types;
      use Type::Tiny::Enum Size => [ qw( S M L XL ) ];
      use namespace::autoclean;
      
      has size => (
         is        => 'ro',
         isa       => Size,
         required  => 1,
      );
      
      sub price {
         my $self = shift;
         my $size = $self->size;
         
         if ( $size eq SIZE_XL ) {
            return 10.99;
         }
         elsif ( $size eq SIZE_L ) {
            return 9.99;
         }
         else {
            return 8.99;
         }
      }
   }

##</code><code>##

   sub post_data ( $url, $data, $ua=undef ) {
      
      use Type::Tiny::Class -lexical, 'HTTP::Tiny';
      
      $ua = HTTPTiny->new unless is_HTTPTiny $ua;
      $ua->post( $url, $data );
   }

##</code><code>##

   use Types::Common -all;

##</code><code>##

   use Types::Common qw( signature_for Num NonEmptyStr );
</pre>

<p>If you have a bleeding-edge Perl installed, you can import functions lexically:</p>

<c>
   use Types::Common -lexical, -all;

##</code><code>##

   has lucky_numbers => (
      is    => 'ro',
      isa   => ArrayRef[ Num / Any ],
   );

##</code><code>##

   has output_list => (
      is        => 'ro',
      isa       => ArrayRef,
      default   => sub { [] },
   );

##</code><code>##

   has output_list => (
      is        => 'ro',
      isa       => ArrayRef,
      default   => ArrayRef->type_default,
   );

##</code><code>##

   has colour_scheme => (
      is        => 'ro',
      isa       => ColourScheme,
      default   => sub {
         my %colours = (
            foreground => 'black',
            background => 'white',
            links      => 'blue',
            highlight  => 'red',
         );
         return \%colours;
      },
   );