wt-dbo

问题 Wt recommends to use forward declarations to avoid circular dependencies. // Settings.h #include <Wt/Dbo/Dbo.h> #include <string> class User; // Forward declaration of User Wt::Dbo object class Settings { public: Wt::Dbo::ptr<User> user; template<class Action> void persist(Action& a) { Wt::Dbo::belongsTo(a, user); } }; // User.h #include <Wt/Dbo/Dbo.h> #include <string> #include "Settings.h" class User { public: Wt::Dbo::weak_ptr<Settings> settings; template<class Action> void persist(Action&