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- package overloading;
- use warnings;
- our $VERSION = '0.02';
- my $HINT_NO_AMAGIC = 0x01000000; # see perl.h
- require 5.010001;
- sub _ops_to_nums {
- require overload::numbers;
- map { exists $overload::numbers::names{"($_"}
- ? $overload::numbers::names{"($_"}
- : do { require Carp; Carp::croak("'$_' is not a valid overload") }
- } @_;
- }
- sub import {
- my ( $class, @ops ) = @_;
- if ( @ops ) {
- if ( $^H{overloading} ) {
- vec($^H{overloading} , $_, 1) = 0 for _ops_to_nums(@ops);
- }
- if ( $^H{overloading} !~ /[^\0]/ ) {
- delete $^H{overloading};
- $^H &= ~$HINT_NO_AMAGIC;
- }
- } else {
- delete $^H{overloading};
- $^H &= ~$HINT_NO_AMAGIC;
- }
- }
- sub unimport {
- my ( $class, @ops ) = @_;
- if ( exists $^H{overloading} or not $^H & $HINT_NO_AMAGIC ) {
- if ( @ops ) {
- vec($^H{overloading} ||= '', $_, 1) = 1 for _ops_to_nums(@ops);
- } else {
- delete $^H{overloading};
- }
- }
- $^H |= $HINT_NO_AMAGIC;
- }
- 1;
- __END__
- =head1 NAME
- overloading - perl pragma to lexically control overloading
- =head1 SYNOPSIS
- {
- no overloading;
- my $str = "$object"; # doesn't call stringification overload
- }
- # it's lexical, so this stringifies:
- warn "$object";
- # it can be enabled per op
- no overloading qw("");
- warn "$object";
- # and also reenabled
- use overloading;
- =head1 DESCRIPTION
- This pragma allows you to lexically disable or enable overloading.
- =over 6
- =item C<no overloading>
- Disables overloading entirely in the current lexical scope.
- =item C<no overloading @ops>
- Disables only specific overloads in the current lexical scope.
- =item C<use overloading>
- Reenables overloading in the current lexical scope.
- =item C<use overloading @ops>
- Reenables overloading only for specific ops in the current lexical scope.
- =back
- =cut
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