NAME
    Module::Hash - a tied hash that requires modules for you

SYNOPSIS
            use strict;
            use Test::More tests => 1;
            use Module::Hash;
        
            tie my %MOD, "Module::Hash";
        
            my $number = $MOD{"Math::BigInt"}->new(42);
        
            ok( $number->isa("Math::BigInt") );

DESCRIPTION
    Module::Hash provides a tied hash that can be used to load and quote
    module names.

  Tied Interface
            tie my %MOD, "Module::Hash", %options;

    The hash is tied to Module::Hash. Every time you fetch a hash key, such as
    $MOD{"Math::BigInt"} that module is loaded, and the module name is
    returned as a string. Thus the following works without you needing to load
    Math::BigInt in advance.

            $MOD{"Math::BigInt"}->new(...)

    You may wonder what the advantage is of this hash, rather that using good
    old:

            require Math::BigInt;
            Math::BigInt->new(...)

    Well, the latter is actually ambiguous. Try defining a sub called `BigInt`
    in the `Math` package!

    You can provide an optional minimum version number for the module. The
    module will be checked against the required version number, but the
    version number will not be included in the returned string. Thus the
    following works:

            $MOD{"Math::BigInt 1.00"}->new(...)

    The following options are supported:

    *   prefix - an optional prefix for modules

                tie my $MATH, "Module::Hash", prefix => "Math";
                my $number = $MATH{BigInt}->new(42);

    *   optimistic - a boolean. If the hash is optimistic, then it doesn't
        croak when modules are missing; it silently returns the module name
        anyway. Hashes are optimistic by default; you need to explicitly
        pessimize them:

                tie my $MOD, "Module::Hash", optimistic => 0;

    Attempting to modify the hash will croak.

  Import-Oriented Interface
    If you just want to use the default options, you can supply a reference to
    the hash in the import statement:

            my %MOD;
            use Module::Hash \%MOD;
            $MOD{"Math::BigInt"}->new(...);

    Or:

            my $MOD;
            use Module::Hash $MOD;
            $MOD->{"Math::BigInt"}->new(...);

    Little known fact: Perl has a built-in global hash called `%\`. Unlike
    `%+` and `%-` and some other built-in global hashes, the Perl core doesn't
    use it for anything. And I don't think anybody else uses it either. The
    following makes for some cute code...

            use Module::Hash \%\;
            $\{"Math::BigInt"}->new(...);

    ... or an unmaintainable nightmare depending on your perspective.

  Object-Oriented Interface
    This module also provides an object-oriented interface, intended for
    subclassing, etc, etc.

    Methods:

    `new(%options)`
    `optimistic`
    `has_prefix`
    `prefix`
    `use($hash_key)`

BUGS
    Please report any bugs to
    <http://rt.cpan.org/Dist/Display.html?Queue=Module-Hash>.

SEE ALSO
    Most of the tricky stuff is handled by Module::Runtime.

    Module::Quote is similar to this, but more insane. If this module isn't
    insane enough for you, try that.

AUTHOR
    Toby Inkster <tobyink@cpan.org>.

COPYRIGHT AND LICENCE
    This software is copyright (c) 2012 by Toby Inkster.

    This is free software; you can redistribute it and/or modify it under the
    same terms as the Perl 5 programming language system itself.

DISCLAIMER OF WARRANTIES
    THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED
    WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
    MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.