[libsigc++2] Fix the build with GCC 4.6

[David King <davidk src gnome org>]

commit faabe1f90c142a5ea836884a04c0eef250e69f94
Author: Kalev Lember <kalev smartlink ee>
Date:   Fri Feb 4 12:17:05 2011 +0200

    Fix the build with GCC 4.6
    
    * sigc++/signal_base.h: Include <cstddef> for size_t.

 ChangeLog            |    6 ++++++
 sigc++/signal_base.h |    1 +
 2 files changed, 7 insertions(+), 0 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index 76a7baf..39f7558 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2011-02-04  Kalev Lember  <kalev smartlink ee>
+
+	Fix the build with GCC 4.6
+
+	* sigc++/signal_base.h: Include <cstddef> for size_t.
+
 2010-10-12  David King  <davidk openismus com>
 
 	Documentation changes
diff --git a/sigc++/signal_base.h b/sigc++/signal_base.h
index 1638642..e43bd5e 100644
--- a/sigc++/signal_base.h
+++ b/sigc++/signal_base.h
@@ -21,6 +21,7 @@
 #ifndef _SIGC_SIGNAL_BASE_H_
 #define _SIGC_SIGNAL_BASE_H_
 
+#include <cstddef>
 #include <list>
 #include <sigc++config.h>
 #include <sigc++/type_traits.h>