applied patch, modulo parts already added to perldelta

[perl5.git] / pod / perldelta.pod

diff --git a/pod/perldelta.pod b/pod/perldelta.pod
index 6213685..659cb2f 100644 (file)
--- a/pod/perldelta.pod
+++ b/pod/perldelta.pod
@@ -155,9 +155,9 @@ because all reentrancy of the runtime is handled using a "stack of stacks".
 This should improve reliability of cached stack pointers in the internals
 and in XSUBs.
 
 This should improve reliability of cached stack pointers in the internals
 and in XSUBs.
 

-=head2 Behavior of local() on composites is now well-defined
+=head2 Behavior of local() on array and hash elements is now well-defined

 
 

-See L<perlfunc/local>.
+See L<perlsub/"Temporary Values via local()">.

 
 =head2 C<%!> is transparently tied to the L<Errno> module
 
 
 =head2 C<%!> is transparently tied to the L<Errno> module
 


@@ -171,10 +171,6 @@ See L<perlref>.
 
 See L<perlsyn>.
 
 
 See L<perlsyn>.
 

-=head2 Slice notation on glob elements is supported
-
-[XXX See what?]
-

 =head2 Keywords can be globally overridden
 
 See L<perlsub>.
 =head2 Keywords can be globally overridden
 
 See L<perlsub>.


@@ -277,6 +273,28 @@ Splice() with a negative LENGTH argument now work similar to what the
 LENGTH did for substr().  Previously a negative LENGTH was treated as
 0.  See L<perlfunc/splice>.
 
 LENGTH did for substr().  Previously a negative LENGTH was treated as
 0.  See L<perlfunc/splice>.
 

+=head2 Magic lvalues are now more magical
+
+When you say something like C<substr($x, 5) = "hi">, the scalar returned
+by substr() is special, in that any modifications to it affect $x.
+(This is called a 'magic lvalue' because an 'lvalue' is something on
+the left side of an assignment.)  Normally, this is exactly what you
+would expect to happen, but Perl uses the same magic if you use substr(),
+pos(), or vec() in a context where they might be modified, like taking
+a reference with C<\> or as an argument to a sub that modifies C<@_>.
+In previous versions, this 'magic' only went one way, but now changes
+to the scalar the magic refers to ($x in the above example) affect the
+magic lvalue too. For instance, this code now acts differently:
+
+    $x = "hello";
+    sub printit {
+       $x = "g'bye";
+       print $_[0], "\n";
+    }
+    printit(substr($x, 0, 5));
+
+In previous versions, this would print "hello", but it now prints "g'bye".
+

 
 =head1 Supported Platforms
 
 
 =head1 Supported Platforms