Groundwork for exception support:

     Auto generate result structs that combine return type and any thrown exceptions
     Add __isset struct to all user defined and auto defined struct to mark fields that are explicilty read
     Modified client and server generation code to marshal result structs

     Added base facebook::thrift::Exception class 


git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@664750 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/lib/cpp/src/Thrift.h b/lib/cpp/src/Thrift.h
index 9986e3b..1f98d82 100644
--- a/lib/cpp/src/Thrift.h
+++ b/lib/cpp/src/Thrift.h
@@ -7,5 +7,20 @@
 #include <map>
 #include <list>
 #include <set>
+#include <exception>
+
+namespace facebook {namespace thrift {
+
+class Exception : public std::exception {
+private:
+  const std::string _message;
+
+public:
+  Exception(const std::string message) : _message(message) {}
+  ~Exception() throw () {}
+  const char* what() {return _message.c_str();}
+};
+
+}} // facebook::thrift
 
 #endif