NAME
    Type::Tie - tie a variable to a type constraint

SYNOPSIS
    Type::Tie is a response to this sort of problem...

       use strict;
       use warnings;
   
       {
          package Local::Testing;
          use Moose;
          has numbers => ( is => "ro", isa => "ArrayRef[Num]" );
       }
   
       # Nice list of numbers.
       my @N = ( 1, 2, 3, 3.14159 );
   
       # Create an object with a reference to that list.
       my $object = Local::Testing->new(numbers => \@N);
   
       # Everything OK so far...
   
       # Now watch this!
       push @N, "Monkey!";
       print $object->dump;
   
       # Houston, we have a problem!

    Just declare @N like this:

       use Type::Tie;
       use Types::Standard qw( Num );
   
       ttie my @N, Num, ( 1, 2, 3, 3.14159 );

    Now any attempt to add a non-numeric value to @N will die.

DESCRIPTION
    This module exports a single function: `ttie`. `ttie` ties a variable to a
    type constraint, ensuring that whatever values stored in the variable will
    conform to the type constraint. If the type constraint has coercions,
    these will be used if necessary to ensure values assigned to the variable
    conform.

       use Type::Tie;
       use Types::Standard qw( Int Num );
   
       ttie my $count, Int->plus_coercions(Num, 'int $_'), 0;
   
       $count++;            # ok
       $count = 2;          # ok
       $count = 3.14159;    # ok, coerced to 3
       $count = "Monkey!";  # dies

    While the examples in documentation (and the test suite) show type
    constraints from Types::Standard, but any type constraint objects
    supporting the Type::API interfaces should work. This includes:

    *   Moose::Meta::TypeConstraint / MooseX::Types

    *   Mouse::Meta::TypeConstraint / MouseX::Types

    *   Specio

    *   Type::Tiny

BUGS
    Please report any bugs to
    <http://rt.cpan.org/Dist/Display.html?Queue=Type-Tie>.

SUPPORT
    IRC: support is available through in the *#moops* channel on irc.perl.org
    <http://www.irc.perl.org/channels.html>.

SEE ALSO
    Type::API, Type::Utils, Moose::Manual::Types, MooseX::Lexical::Types.

AUTHOR
    Toby Inkster <tobyink@cpan.org>.

COPYRIGHT AND LICENCE
    This software is copyright (c) 2013-2014 by Toby Inkster.

    This is free software; you can redistribute it and/or modify it under the
    same terms as the Perl 5 programming language system itself.

DISCLAIMER OF WARRANTIES
    THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED
    WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
    MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.