package if;

$VERSION = '0.05';

sub work {
    my $method = shift() ? 'import' : 'unimport';
    die
      "Too few arguments to `use if' (some code returning an empty list in list context?)"
      unless @_ >= 2;
    return unless shift;    # CONDITION

    my $p = $_[0];          # PACKAGE
    ( my $file = "$p.pm" ) =~ s!::!/!g;
    require $file;          # Works even if $_[0] is a keyword (like open)
    my $m = $p->can($method);
    goto &$m if $m;
}

sub import   { shift; unshift @_, 1; goto &work }
sub unimport { shift; unshift @_, 0; goto &work }

1;
__END__

=head1 NAME

if - C<use> a Perl module if a condition holds

=head1 SYNOPSIS

  use if CONDITION, MODULE => ARGUMENTS;

=head1 DESCRIPTION

The construct

  use if CONDITION, MODULE => ARGUMENTS;

has no effect unless C<CONDITION> is true.  In this case the effect is
the same as of

  use MODULE ARGUMENTS;

Above C<< => >> provides necessary quoting of C<MODULE>.  If not used (e.g.,
no ARGUMENTS to give), you'd better quote C<MODULE> yourselves.

=head1 BUGS

The current implementation does not allow specification of the
required version of the module.

=head1 AUTHOR

Ilya Zakharevich L<mailto:perl-module-if@ilyaz.org>.

=cut