The C<:unique> attribute has been made a no-op, since its current
implementation was fundamentally flawed and not threadsafe.
+=head2 Scoping of the C<sort> pragma
+
+The C<sort> pragma is now lexically scoped. Its effect used to be global.
+
=head1 Core Enhancements
+=head2 The C<feature> pragma
+
+The C<feature> pragma is used to enable new syntax that would break Perl's
+backward-compatibility with older releases of the language. It's a lexical
+pragma, like C<strict> or C<warnings>.
+
+Currently the following new features are available: C<switch> (adds a
+switch statement), C<~~> (adds a Perl 6-like smart match operator), C<say>
+(adds a C<say> built-in function), and C<err> (adds an C<err> keyword).
+Those features are described below.
+
+Note that C<err> low-precedence defined-or operator used to be enabled by
+default, but as a weak keyword. It's now only recognized when explicitely
+turned on.
+
=head2 Switch and Smart Match operator
+XXX
+
=head2 C<say()>
+say() is a new built-in, only avaiable when C<use feature 'say'> is in
+effect, that is similar to print(), but that implicitly appends a newline
+to the printed string. See L<perlfunc/say>.
+
=head2 C<CLONE_SKIP()>
Perl has now support for the C<CLONE_SKIP> special subroutine. Like
You can now use C<no> followed by a version number to specify that you
want to use a version of perl inferior to the specified one.
+=head2 Recursive sort subs
+
+You can now use recursive subroutines with sort().
+
+=head2 Effect of pragmas in eval
+
+The compile-time value of the C<%^H> hint variable can now propagate into
+eval("")uated code. This makes it more useful to implement lexical
+pragmas.
+
+As a side-effect of this, the overloaded-ness of constants now propagates
+into eval("").
+
+=head2 New B<-E> command-line switch
+
+B<-E> is equivalent to B<-e>, but it implicitly enables all
+optional features.
+
=head1 Modules and Pragmata
=head2 C<feature>
+This new module implements the C<feature> pragma; see above in
+L</"Core Enhancements">.
+
=head2 C<assertions::compat>
=head2 C<Math::BigInt::FastCalc>
=head1 Performance Enhancements
+=head2 XS-assisted SWASHGET
+
+Some pure-perl code that perl was using to retrieve Unicode properties and
+transliteration mappings has been retrieved in XS.
+
+=head2 Constants subroutines
+
+XXX
+
=head1 Installation and Configuration Improvements
=head2 New Or Improved Platforms
Perl is being ported to Symbian OS. See L<perlsymbian> for more
information.
+The VMS port has been improved. See L<perlvms>.
+
+DynaLoader::dl_unload_file() now works on Windows.
+
+Portability of Perl on various recent compilers on Windows has been
+improved (Borland C++, Visual C++ 7.0).
+
+=head2 New probes
+
+Perl will detect and use internally futimes(2) if available.
+
=head2 Module auxiliary files
README files and changelogs for CPAN modules bundled with perl are no
C<defined %$foo> are still allowed. Those constructs are discouraged
anyway.)
+=head2 Calling CORE::require()
+
+CORE::require() and CORE::do() were always parsed as require() and do()
+when they were overriden. This is now fixed.
+
+=head2 Subscripts of slices
+
+You can now use a non-arrowed form for chained subscripts after a list
+slice, like in:
+
+ ({foo => "bar"})[0]{foo}
+
+This used to be a syntax error; a C<< -> >> was required.
+
+=head2 Remove over-optimisation
+
+Perl 5.9.2 introduced a change so that assignments of C<undef> to a
+scalar, or of an empty list to an array or a hash, were optimised out. As
+this could cause problems when C<goto> jumps were involved, this change
+was backed out.
+
+=head2 sprintf() fixes
+
+Using the sprintf() function with some formats could lead to a buffer
+overflow in some specific cases. This has been fixed, along with several
+other bugs, notably in bound checking.
+
+In related fixes, a format string injection vulnerability has been fixed
+in Sys::Syslog.
+
=head2 Smaller fixes
=over 4
=item *
-Several memory leaks in ithreads were closed.
+Several memory leaks in ithreads were closed. Also, ithreads were made
+less memory-intensive.
=item *
You can now use the C<x> operator to demultiply a C<qw//> list. This used
to raise a syntax error.
+=item *
+
+The debugger now traces correctly execution in eval("")uated code that
+contains #line directives.
+
+=item *
+
+The value of the C<open> pragma is no longer ignored for three-argument
+opens.
+
+=item *
+
+C<//g> matches used to loop infinitely on tainted data.
+
=back
=head2 More Unicode Fixes
now gives a C<"our" variable %s redeclared> warning.
+=head2 readdir()/closedir()/etc. attempted on invalid dirhandle
+
+These new warnings are now emitted when a dirhandle is used but is
+either closed or not really a dirhandle.
+
=head1 Changed Internals
XXX consting
-XXX mathoms
+A new file, F<mathoms.c>, has been added. It contains functions that are
+no longer used in the perl core, but that remain available for binary or
+source compatibility reasons. However, those functions will not be
+compiled in if you add C<-DNO_MATHOM> in the compiler flags.
The C<AvFLAGS> macro has been removed.