From: "Georgios M. Zarkadas" <georgios.zarkadas@gmail.com>
Subject: fix FTBFS with gcc 4.6
diff --git a/encoded_char.h b/encoded_char.h
index 819c993..6b9a371 100644
--- a/encoded_char.h
+++ b/encoded_char.h
@@ -25,6 +25,7 @@
 // standard
 #include <iterator>
 #include <set>
+#include <cstddef>
 
 // local
 #include "iso8859-1.h"
