Update to Scalar-List-Utils-1.15

[p5sagit/p5-mst-13.2.git] / ext / List / Util / lib / Scalar / Util.pm

diff --git a/ext/List/Util/lib/Scalar/Util.pm b/ext/List/Util/lib/Scalar/Util.pm
index 089a436..d8b1625 100644 (file)
--- a/ext/List/Util/lib/Scalar/Util.pm
+++ b/ext/List/Util/lib/Scalar/Util.pm
@@ -1,6 +1,6 @@
 # Scalar::Util.pm
 #
-# Copyright (c) 1997-2004 Graham Barr <gbarr@pobox.com>. All rights reserved.
+# Copyright (c) 1997-2005 Graham Barr <gbarr@pobox.com>. All rights reserved.
 # This program is free software; you can redistribute it and/or
 # modify it under the same terms as Perl itself.
 
@@ -11,7 +11,7 @@ require List::Util; # List::Util loads the XS
 
 @ISA       = qw(Exporter);
 @EXPORT_OK = qw(blessed dualvar reftype weaken isweak tainted readonly openhandle refaddr isvstring looks_like_number set_prototype);
-$VERSION    = "1.14_1";
+$VERSION    = "1.15";
 $VERSION   = eval $VERSION;
 
 sub export_fail {
@@ -274,6 +274,25 @@ prevent the object being DESTROY-ed at its usual time.
     }
     # $ref is now undef
 
+Note that if you take a copy of a scalar with a weakened reference,
+the copy will be a strong reference.
+
+    my $var;
+    my $foo = \$var;
+    weaken($foo);                       # Make $foo a weak reference
+    my $bar = $foo;                     # $bar is now a strong reference
+
+This may be less obvious in other situations, such as C<grep()>, for instance
+when grepping through a list of weakened references to objects that may have
+been destroyed already:
+
+    @object = grep { defined } @object;
+
+This will indeed remove all references to destroyed objects, but the remaining
+references to objects will be strong, causing the remaining objects to never
+be destroyed because there is now always a strong reference to them in the
+@object array.
+
 =back
 
 =head1 KNOWN BUGS
@@ -283,7 +302,7 @@ show up as tests 8 and 9 of dualvar.t failing
 
 =head1 COPYRIGHT
 
-Copyright (c) 1997-2004 Graham Barr <gbarr@pobox.com>. All rights reserved.
+Copyright (c) 1997-2005 Graham Barr <gbarr@pobox.com>. All rights reserved.
 This program is free software; you can redistribute it and/or modify it
 under the same terms as Perl itself.