fixed not returning the same submodule on a second call of the...

fixed not returning the same submodule on a second call of the ControlSystemModule::operator[] with the same module name

include/ControlSystemModule.h

@@ -33,10 +33,7 @@ namespace ChimeraTK {
         return operator()(variableName, typeid(AnyType));
       }
 
-      Module& operator[](const std::string& moduleName) const override {
-        subModules.emplace_back(variableNamePrefix/moduleName);
-        return subModules.back();
-      }
+      Module& operator[](const std::string& moduleName) const override;
 
     protected:
 
@@ -44,7 +41,7 @@ namespace ChimeraTK {
       
       // List of sub modules accessed through the operator[]. This is mutable since it is little more than a cache and
       // thus does not change the logical state of this module
-      mutable std::list<ControlSystemModule> subModules;
+      mutable std::map<std::string, ControlSystemModule> subModules;
       
       // List of variables accessed through the operator(). This is mutable since it is little more than a cache and
       // thus does not change the logical state of this module

src/ControlSystemModule.cc

@@ -25,4 +25,13 @@ namespace ChimeraTK {
     return variables[variableName];
   }
 
+  /*********************************************************************************************************************/
+
+  Module& ControlSystemModule::operator[](const std::string& moduleName) const {
+    if(subModules.count(moduleName) == 0) {
+      subModules[moduleName] = {variableNamePrefix/moduleName};
+    }
+    return subModules[moduleName];
+  }
+
 }