# deprecate - phpMan

## NAME
    deprecate - Perl pragma for deprecating the inclusion of a module in
    core

## SYNOPSIS
        use deprecate;  # warn about future absence if loaded from core

## DESCRIPTION
    This pragma simplifies the maintenance of dual-life modules that will no
    longer be included in the Perl core in a future Perl release, but are
    still included currently.

    The purpose of the pragma is to alert users to the status of such a
    module by issuing a warning that encourages them to install the module
    from CPAN, so that a future upgrade to a perl which omits the module
    will not break their code.

    This warning will only be issued if the module was loaded from a core
    library directory, which allows the "use deprecate" line to be included
    in the CPAN version of the module. Because the pragma remains silent
    when the module is run from a non-core library directory, the pragma
    call does not need to be patched into or out of either the core or CPAN
    version of the module. The exact same code can be shipped for either
    purpose.

  Important Caveat
    Note that when a module installs from CPAN to a core library directory
    rather than the site library directories, the user gains no protection
    from having installed it.

    At the same time, this pragma cannot detect when such a module has
    installed from CPAN to the core library, and so it would endlessly and
    uselessly exhort the user to upgrade.

    Therefore modules that can install from CPAN to the core library must
    make sure not to call this pragma when they have done so. Generally this
    means that the exact logic from the installer must be mirrored inside
    the module. E.g.:

        # Makefile.PL
        WriteMakefile(
            # ...
            INSTALLDIRS => ( "$]" >= 5.011 ? 'site' : 'perl' ),
        );

        # lib/Foo/Bar.pm
        use if "$]" >= 5.011, 'deprecate';

    (The above example shows the most important case of this: when the
    target is a Perl older than 5.12 (where the core library directories
    take precedence over the site library directories) and the module being
    installed was included in core in that Perl version. Under those
    circumstances, an upgrade of the module from CPAN is only possible by
    installing to the core library.)

## EXPORT
    None by default. The only method is "import", called by "use
    deprecate;".

## SEE ALSO
    First example to "use deprecate;" was Switch.

## AUTHOR
    Original version by Nicholas Clark

## COPYRIGHT AND LICENSE
    Copyright (C) 2009, 2011

    This library is free software; you can redistribute it and/or modify it
    under the same terms as Perl itself, either Perl version 5.10.0 or, at
    your option, any later version of Perl 5 you may have available.