astyle 2.03 is out including a lot of fixes for C++11, see http://astyle.sourceforge.net/notes.html for details
Bumping the ebuild and copying the astyle-2.02.1-build_system.patch works for me and looking at the code it looks like the patch is still needed and it doesn't look like any new dependencies was added.
+*astyle-2.03 (24 Apr 2013)
+ 24 Apr 2013; Kacper Kowalik <email@example.com> +astyle-2.03.ebuild,
+ -astyle-1.22.ebuild, -astyle-1.24.ebuild, -files/astyle-1.22-Makefile.patch,
+ Version bump wrt #466198 by David Hallas <firstname.lastname@example.org>. Drop old
Works like a charm, thanks a lot for the quick update!