Tie::Scalar - phpMan

NAME
    Tie::Scalar, Tie::StdScalar - base class definitions for tied scalars

SYNOPSIS
        package NewScalar;
        require Tie::Scalar;

        @ISA = qw(Tie::Scalar);

        sub FETCH { ... }           # Provide a needed method
        sub TIESCALAR { ... }       # Overrides inherited method


        package NewStdScalar;
        require Tie::Scalar;

        @ISA = qw(Tie::StdScalar);

        # All methods provided by default, so define
        # only what needs be overridden
        sub FETCH { ... }


        package main;

        tie $new_scalar, 'NewScalar';
        tie $new_std_scalar, 'NewStdScalar';

DESCRIPTION
    This module provides some skeletal methods for scalar-tying classes. See
    perltie for a list of the functions required in tying a scalar to a
    package. The basic Tie::Scalar package provides a "new" method, as well
    as methods "TIESCALAR", "FETCH" and "STORE". The Tie::StdScalar package
    provides all the methods specified in perltie. It inherits from
    Tie::Scalar and causes scalars tied to it to behave exactly like the
    built-in scalars, allowing for selective overloading of methods. The
    "new" method is provided as a means of grandfathering, for classes that
    forget to provide their own "TIESCALAR" method.

    For developers wishing to write their own tied-scalar classes, the
    methods are summarized below. The perltie section not only documents
    these, but has sample code as well:

    TIESCALAR classname, LIST
        The method invoked by the command "tie $scalar, classname".
        Associates a new scalar instance with the specified class. "LIST"
        would represent additional arguments (along the lines of AnyDBM_File
        and compatriots) needed to complete the association.

    FETCH this
        Retrieve the value of the tied scalar referenced by *this*.

    STORE this, value
        Store data *value* in the tied scalar referenced by *this*.

    DESTROY this
        Free the storage associated with the tied scalar referenced by
        *this*. This is rarely needed, as Perl manages its memory quite
        well. But the option exists, should a class wish to perform specific
        actions upon the destruction of an instance.

  Tie::Scalar vs Tie::StdScalar
    "Tie::Scalar" provides all the necessary methods, but one should realize
    they do not do anything useful. Calling "Tie::Scalar::FETCH" or
    "Tie::Scalar::STORE" results in a (trappable) croak. And if you inherit
    from "Tie::Scalar", you *must* provide either a "new" or a "TIESCALAR"
    method.

    If you are looking for a class that does everything for you that you
    don't define yourself, use the "Tie::StdScalar" class, not the
    "Tie::Scalar" one.

MORE INFORMATION
    The perltie section uses a good example of tying scalars by associating
    process IDs with priority.