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Diffstat (limited to 'contrib/perl5/lib/UNIVERSAL.pm')
-rw-r--r-- | contrib/perl5/lib/UNIVERSAL.pm | 101 |
1 files changed, 0 insertions, 101 deletions
diff --git a/contrib/perl5/lib/UNIVERSAL.pm b/contrib/perl5/lib/UNIVERSAL.pm deleted file mode 100644 index f2f1fe9e7ade..000000000000 --- a/contrib/perl5/lib/UNIVERSAL.pm +++ /dev/null @@ -1,101 +0,0 @@ -package UNIVERSAL; - -# UNIVERSAL should not contain any extra subs/methods beyond those -# that it exists to define. The use of Exporter below is a historical -# accident that should be fixed sometime. -require Exporter; -*import = \&Exporter::import; -@EXPORT_OK = qw(isa can); - -1; -__END__ - -=head1 NAME - -UNIVERSAL - base class for ALL classes (blessed references) - -=head1 SYNOPSIS - - $io = $fd->isa("IO::Handle"); - $sub = $obj->can('print'); - - $yes = UNIVERSAL::isa($ref, "HASH"); - -=head1 DESCRIPTION - -C<UNIVERSAL> is the base class which all bless references will inherit from, -see L<perlobj> - -C<UNIVERSAL> provides the following methods - -=over 4 - -=item isa ( TYPE ) - -C<isa> returns I<true> if C<REF> is blessed into package C<TYPE> -or inherits from package C<TYPE>. - -C<isa> can be called as either a static or object method call. - -=item can ( METHOD ) - -C<can> checks if the object has a method called C<METHOD>. If it does -then a reference to the sub is returned. If it does not then I<undef> -is returned. - -C<can> can be called as either a static or object method call. - -=item VERSION ( [ REQUIRE ] ) - -C<VERSION> will return the value of the variable C<$VERSION> in the -package the object is blessed into. If C<REQUIRE> is given then -it will do a comparison and die if the package version is not -greater than or equal to C<REQUIRE>. - -C<VERSION> can be called as either a static or object method call. - -=back - -The C<isa> and C<can> methods can also be called as subroutines - -=over 4 - -=item UNIVERSAL::isa ( VAL, TYPE ) - -C<isa> returns I<true> if one of the following statements is true. - -=over 8 - -=item * - -C<VAL> is a reference blessed into either package C<TYPE> or a package -which inherits from package C<TYPE>. - -=item * - -C<VAL> is a reference to a C<TYPE> of Perl variable (e.g. 'HASH'). - -=item * - -C<VAL> is the name of a package that inherits from (or is itself) -package C<TYPE>. - -=back - -=item UNIVERSAL::can ( VAL, METHOD ) - -If C<VAL> is a blessed reference which has a method called C<METHOD>, -C<can> returns a reference to the subroutine. If C<VAL> is not -a blessed reference, or if it does not have a method C<METHOD>, -I<undef> is returned. - -=back - -These subroutines should I<not> be imported via S<C<use UNIVERSAL qw(...)>>. -If you want simple local access to them you can do - - *isa = \&UNIVERSAL::isa; - -to import isa into your package. - -=cut |