NAME

       Class::Meta::Types::Boolean - Boolean data types

SYNOPSIS

         package MyApp::Thingy;
         use strict;
         use Class::Meta;
         use Class::Meta::Types::Boolean;
         # OR...
         # use Class::Meta::Types::Boolean 'affordance';
         # OR...
         # use Class::Meta::Types::Boolean 'semi-affordance';

         BEGIN {
             # Create a Class::Meta object for this class.
             my $cm = Class::Meta->new( key => 'thingy' );

             # Add a boolean attribute.
             $cm->add_attribute( name => 'alive',
                                 type => 'boolean' );
             $cm->build;
         }

DESCRIPTION

       This module provides a boolean data type for use with Class::Meta attributes.  Simply load
       it, then pass "boolean" (or the alias "bool") to the "add_attribute()" method of a
       Class::Meta object to create an attribute of the boolean data type. See Class::Meta::Type
       for more information on using and creating data types.

   Accessors
       Although the boolean data type has both "default" and "affordance" accessor options
       available, unlike the other data types that ship with Class::Meta, they have different
       implementations. The reason for this is to ensure that the value of a boolean attribute is
       always 0 or 1.

       For the "default" accessor style, there is no difference in the interface from the default
       accessors for other data types. The default accessor merely checks the truth of the new
       value, and assigns 1 if it's a true value, and 0 if it's a false value. The result is an
       efficient accessor that maintains the consistency of the data.

       For the "affordance" accessor style, however, the boolean data type varies in the
       accessors it creates. For example, for a boolean attributed named "alive", instead of
       creating the "get_alive" and "set_alive" accessors common to other affordance-style
       accessors, it instead creates three:

       "is_alive"
       "set_alive_on"
       "set_alive_off"

       The result is highly efficient accessors that ensure the integrity of the data without the
       overhead of validation checks.

SUPPORT

       This module is stored in an open GitHub repository <http://github.com/theory/class-meta/>.
       Feel free to fork and contribute!

       Please file bug reports via GitHub Issues <http://github.com/theory/class-meta/issues/> or
       by sending mail to bug-Class-Meta@rt.cpan.org <mailto:bug-Class-Meta@rt.cpan.org>.

AUTHOR

       David E. Wheeler <david@justatheory.com>

SEE ALSO

       Other classes of interest within the Class::Meta distribution include:

       Class::Meta
           This class contains most of the documentation you need to get started with
           Class::Meta.

       Class::Meta::Type
           This class manages the creation of data types.

       Class::Meta::Attribute
           This class manages Class::Meta class attributes, all of which are based on data types.

       Other data type modules:

       Class::Meta::Types::Perl
       Class::Meta::Types::String
       Class::Meta::Types::Numeric

COPYRIGHT AND LICENSE

       Copyright (c) 2002-2011, David E. Wheeler. Some Rights Reserved.

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