NAME

base - Establish IS-A relationship with base class at compile time

SYNOPSIS

    package Baz;
    use base qw(Foo Bar);

DESCRIPTION

Roughly similar in effect to

    BEGIN {
        require Foo;
        require Bar;
        push @ISA, qw(Foo Bar);
    }

Will also initialize the %FIELDS hash if one of the base classes has it using all public and protected data members of the base classes. Multiple Inheritence of fields is NOT supported. If two or more base classes each have inheritable fields the 'base' pragma will croak. See fields, public and protected for a description of this feature.

Due to the limitations of the pseudo-hash implementation, you must use base before you declare any of your own fields.

When strict 'vars' is in scope, base also lets you assign to @ISA without having to declare @ISA with the 'vars' pragma first.

If any of the base classes are not loaded yet, base silently requires them (but it won't call the import method). Whether to require a base class package is determined by the absence of a global $VERSION in the base package. If $VERSION is not detected even after loading it, base will define $VERSION in the base package, setting it to the string -1, set by base.pm.

HISTORY

This module was introduced with Perl 5.004_04.

NOTE

This is the base.pm which was installed as part of the Class::Fields package. NOT the base.pm which is distributed with Perl. This version should safely emulate everything that 5.6.0's base.pm does. It passes all of 5.6.0's regression tests.

It should also work under 5.005_03, although if you're going to be screwing around with pseudohashes you really should upgrade to 5.6.0.

SEE ALSO

fields, public, protected, protected, Class::Fields