support for exception_ptr and nesting in boost::diagnostic_information

documentation update

[SVN r53038]

include/boost/exception/detail/exception_ptr_base.hpp

@@ -0,0 +1,26 @@
+//Copyright (c) 2006-2009 Emil Dotchevski and Reverge Studios, Inc.
+
+//Distributed under the Boost Software License, Version 1.0. (See accompanying
+//file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef UUID_DC4208C6417811DEBF11E1EC55D89593
+#define UUID_DC4208C6417811DEBF11E1EC55D89593
+
+namespace
+boost
+    {
+	namespace
+	exception_detail
+		{
+		class
+		exception_ptr_base
+			{
+			public:
+
+			virtual void _rethrow() const=0;
+			virtual bool _empty() const=0;
+			};
+		}
+    }
+
+#endif