Introduce support for asynchronous server-side methods (#12)

* Add preliminary changes for async server methods

* Refactor the Message concept and break it into distinctive types

* Continue working on async server methods (high-level API mainly)

* Continue developing support for async server

* Finishing async server methods

* Finishing async server methods (fixing tests & cleaning up)

* A little code cleaning

* Add unit tests for type traits of free functions

* Support for generating async server methods in stub headers

* Update ChangeLog for v0.3.0

* Update the tutorial with how to use async server-side methods

* Update the TOC in sdbus-c++ tutorial

* Update numbering in TOC

* Remove unnecessary code

* Final cleanups

stub-generator/BaseGenerator.cpp

@@ -126,12 +126,15 @@ std::tuple<std::string, std::string, std::string> BaseGenerator::argsToNamesAndT
 /**
  *
  */
-std::string BaseGenerator::outArgsToType(const Nodes& args) const
+std::string BaseGenerator::outArgsToType(const Nodes& args, bool bareList) const
 {
     std::ostringstream retTypeSS;
 
     if (args.size() == 0)
     {
+        if (bareList)
+            return "";
+
         retTypeSS << "void";
     }
     else if (args.size() == 1)
@@ -141,7 +144,8 @@ std::string BaseGenerator::outArgsToType(const Nodes& args) const
     }
     else if (args.size() >= 2)
     {
-        retTypeSS << "std::tuple<";
+        if (!bareList)
+            retTypeSS << "std::tuple<";
 
         bool firstArg = true;
         for (const auto& arg : args)
@@ -150,7 +154,8 @@ std::string BaseGenerator::outArgsToType(const Nodes& args) const
             retTypeSS << signature_to_type(arg->get("type"));
         }
 
-        retTypeSS << ">";
+        if (!bareList)
+            retTypeSS << ">";
     }
 
     return retTypeSS.str();