{
    "mode": "perldoc",
    "parameter": "deprecate",
    "section": "",
    "url": "https://www.chedong.com/phpMan.php/perldoc/deprecate/json",
    "generated": "2026-06-11T02:45:57Z",
    "synopsis": "use deprecate;  # warn about future absence if loaded from core",
    "sections": {
        "NAME": {
            "content": "deprecate - Perl pragma for deprecating the inclusion of a module in core\n",
            "subsections": []
        },
        "SYNOPSIS": {
            "content": "use deprecate;  # warn about future absence if loaded from core\n",
            "subsections": []
        },
        "DESCRIPTION": {
            "content": "This pragma simplifies the maintenance of dual-life modules that will no longer be included in\nthe Perl core in a future Perl release, but are still included currently.\n\nThe purpose of the pragma is to alert users to the status of such a module by issuing a warning\nthat encourages them to install the module from CPAN, so that a future upgrade to a perl which\nomits the module will not break their code.\n\nThis warning will only be issued if the module was loaded from a core library directory, which\nallows the \"use deprecate\" line to be included in the CPAN version of the module. Because the\npragma remains silent when the module is run from a non-core library directory, the pragma call\ndoes not need to be patched into or out of either the core or CPAN version of the module. The\nexact same code can be shipped for either purpose.\n",
            "subsections": [
                {
                    "name": "Important Caveat",
                    "content": "Note that when a module installs from CPAN to a core library directory rather than the site\nlibrary directories, the user gains no protection from having installed it.\n\nAt the same time, this pragma cannot detect when such a module has installed from CPAN to the\ncore library, and so it would endlessly and uselessly exhort the user to upgrade.\n\nTherefore modules that can install from CPAN to the core library must make sure not to call this\npragma when they have done so. Generally this means that the exact logic from the installer must\nbe mirrored inside the module. E.g.:\n\n# Makefile.PL\nWriteMakefile(\n# ...\nINSTALLDIRS => ( \"$]\" >= 5.011 ? 'site' : 'perl' ),\n);\n\n# lib/Foo/Bar.pm\nuse if \"$]\" >= 5.011, 'deprecate';\n\n(The above example shows the most important case of this: when the target is a Perl older than\n5.12 (where the core library directories take precedence over the site library directories) and\nthe module being installed was included in core in that Perl version. Under those circumstances,\nan upgrade of the module from CPAN is only possible by installing to the core library.)\n"
                }
            ]
        },
        "EXPORT": {
            "content": "None by default. The only method is \"import\", called by \"use deprecate;\".\n",
            "subsections": []
        },
        "SEE ALSO": {
            "content": "First example to \"use deprecate;\" was Switch.\n",
            "subsections": []
        },
        "AUTHOR": {
            "content": "Original version by Nicholas Clark\n",
            "subsections": []
        },
        "COPYRIGHT AND LICENSE": {
            "content": "Copyright (C) 2009, 2011\n\nThis library is free software; you can redistribute it and/or modify it under the same terms as\nPerl itself, either Perl version 5.10.0 or, at your option, any later version of Perl 5 you may\nhave available.\n",
            "subsections": []
        }
    },
    "summary": "deprecate - Perl pragma for deprecating the inclusion of a module in core",
    "flags": [],
    "examples": [],
    "see_also": []
}