CMake C# lang version bump and template specialized arguments exception fix

src/CppAst/CMakeLists.txt

@@ -1,11 +1,11 @@
 file(GLOB_RECURSE SOURCE_FILES ${CMAKE_CURRENT_SOURCE_DIR}/*.cs)
 
-set(CMAKE_CSharp_FLAGS "${CMAKE_CSharp_FLAGS} /langversion:7.3")
+set(CMAKE_CSharp_FLAGS "${CMAKE_CSharp_FLAGS} /langversion:10")
 
 add_library(CppAst SHARED ${SOURCE_FILES})
 
 set_target_properties(CppAst PROPERTIES
-    VS_PACKAGE_REFERENCES "ClangSharp_17.0.1;Irony_1.2.0"
+    VS_PACKAGE_REFERENCES "ClangSharp_20.1.2;Irony_1.2.0"
 )
 
 target_compile_options(CppAst PUBLIC "/unsafe")

src/CppAst/CppContainerList.cs

@@ -58,7 +58,17 @@ public void AddRange(IEnumerable<TElement> collection)
             {
                 foreach (var element in collection)
                 {
-                    Add(element);
+                    // Check if given element is already resolved
+                    if (element.Parent == null)
+                    {
+                        // If not, create one
+                        Add(element);
+                    }
+                    else
+                    {
+                        // Otherwise, just reference it
+                        _elements.Add(element);
+                    }
                 }
             }
         }