is_error_type, renamed peek_next_error to next_error_value

example/lua_callback_eh.cpp

@@ -25,6 +25,9 @@ enum do_work_error_code
 	ec1=1,
 	ec2
 };
+namespace boost { namespace leaf {
+	template<> struct is_error_type<do_work_error_code>: std::true_type { };
+} }
 
 struct e_lua_pcall_error { int value; };
 struct e_lua_error_message { std::string value; };