From: Perl 5 Porters <perl5-porters@africa.nicoh.com>
Date: Tue, 18 Jun 1996 07:41:37 +0000 (+0000)
Subject: perl 5.003_01: lib/overload.pm
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=3bc6ec8038d110d76f73b0833a2cc894ac5ab2cb;p=p5sagit%2Fp5-mst-13.2.git

perl 5.003_01: lib/overload.pm

Drop support for null package name or package "0"
Document fallbacks for logical negation
---

diff --git a/lib/overload.pm b/lib/overload.pm
index 54d2cbb..28e7d0b 100644
--- a/lib/overload.pm
+++ b/lib/overload.pm
@@ -26,18 +26,18 @@ sub unimport {
 }
 
 sub Overloaded {
-  defined ($package = ref $_[0]) and defined %{$package . "::OVERLOAD"};
+  ($package = ref $_[0]) and defined %{$package . "::OVERLOAD"};
 }
 
 sub OverloadedStringify {
-  defined ($package = ref $_[0]) and 
+  ($package = ref $_[0]) and 
     defined %{$package . "::OVERLOAD"} and 
       exists $ {$package . "::OVERLOAD"}{'""'} and
 	defined &{$ {$package . "::OVERLOAD"}{'""'}};
 }
 
 sub Method {
-  defined ($package = ref $_[0]) and 
+  ($package = ref $_[0]) and 
     defined %{$package . "::OVERLOAD"} and 
       $ {$package . "::OVERLOAD"}{$_[1]};
 }
@@ -186,7 +186,9 @@ arrays, C<cmp> is used to compare values subject to C<use overload>.
     "&", "^", "|", "neg", "!", "~",
 
 "C<neg>" stands for unary minus.  If the method for C<neg> is not
-specified, it can be autogenerated using the method for subtraction.
+specified, it can be autogenerated using the method for
+subtraction. If the method for "C<!>" is not specified, it can be
+autogenerated using the methods for "C<bool>", or "C<\"\">", or "C<0+>".
 
 =item * I<Increment and decrement>
 
@@ -361,6 +363,11 @@ can be expressed in terms of C<$aE<lt>0> and C<-$a> (or C<0-$a>).
 
 can be expressed in terms of subtraction.
 
+=item I<Negation>
+
+C<!> and C<not> can be expressed in terms of boolean conversion, or
+string or numerical conversion.
+
 =item I<Concatenation>
 
 can be expressed in terms of string conversion.