As for the warning, MSVC is probably winning about this

// GraphElements are NOT COPYABLE nor MOVEABLE
GraphElementParent(GraphElementParent&&) = delete;
GraphElementParent(const GraphElementParent&&) = delete;
GraphElementParent(GraphElementParent& ) = delete;
GraphElementParent(const GraphElementParent& ) = delete;

Since I don't have access to a valid MSVC, just tell what to put (normally this is valid code )