Man pages sections > man3 > Alt::Assert

Alt::Assert - Assert alternate module implementation

Alt::Assert(3pm) User Contributed Perl Documentation Alt::Assert(3pm)

NAME

Alt::Assert - Assert alternate module implementation

SYNOPSIS

Assuming there is a CPAN module Foo::Bar and mst wants to write an ALTernate called Alt::Foo::Bar::MSTROUT.
In mst's Foo::Bar, there is the following line:
    use constant ALT => 'MSTROUT';
In the alt module:
    package Alt::Foo::Bar::MSTROUT;
    use Alt::Assert; # imports assert()
    1;
Users use mst's Foo::Bar as normal, just like they would use the original Foo::Bar:
    use Foo::Bar -various => [qw(weird import)], {API=>'things'};
or:
    require Foo::Bar;
If they want to assert they have the mst version, they can:
    use Foo::Bar -various => [qw(weird import)], {API=>'things'};
    use Alt::Foo::Bar::MSTROUT;
or:
    require Foo::Bar;
    require Alt::Foo::Bar::MSTROUT;
    Alt::Foo::Bar::MSTROUT->assert;

DESCRIPTION

Alt::Assert can be used to assert that the loaded module is the wanted alternate implementation. Using the Synopsis' example, there can be different Foo::Bar installed, either from the original distribution, or from one of the alternate ones. Each alternate might be slightly incompatible with the original. The existence of Alt::Foo::Bar::MSTROUT in the installation does not necessarily ensure that the installed Foo::Bar is from the same alternate distribution, since an installer can replace Foo::Bar from another distribution. That is why one might need to do this assertion.

SEE ALSO

Alt

AUTHOR

Ingy doet Net <ingy@cpan.org> Copyright 2012-2014. Ingy doet Net.
See <http://www.perl.com/perl/misc/Artistic.html>
2014-12-29 perl v5.20.2