Add polymorphic_pointer_cast

include/boost/polymorphic_pointer_cast.hpp

@@ -1,5 +1,5 @@
 //  boost polymorphic_pointer_cast.hpp header file  ----------------------------------------------//
-//  (C) Copyright Boris Rasin 2014.
+//  (C) Copyright Boris Rasin and Antony Polukhin 2014.
 //  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)
@@ -61,6 +61,17 @@ namespace boost
         return static_pointer_cast<Target> (x);
     }
 
+    template <typename Target, typename Source>
+    inline typename detail::static_pointer_cast_result<Target, Source>::type
+    polymorphic_pointer_cast (const Source& x)
+    {
+        typename detail::static_pointer_cast_result<Target, Source>::type tmp
+            = dynamic_pointer_cast<Target> (x);
+        if ( !tmp ) boost::throw_exception( std::bad_cast() );
+
+        return tmp;
+    }
+
 } // namespace boost
 
 #endif  // BOOST_CONVERSION_POLYMORPHIC_POINTER_CAST_HPP