Port, InputPort, and OutputPort

The Port.h file defines three classes Port, InputPort and OutputPort as follows.

class Port: public Named {
public:
    Devs* Parent;
    vector<Port*> ToP;   // Successor
    vector<Port*> FromP; // Predecessor
    ...
};

class InputPort: public Port {
    ...
};

class OutputPort: public Port {
    ...
};

Port is an abstract class derived from Named. It has a parent pointer whose type is Devs pointer and which is automatically assigned when we call the AddIP() and AddOP() functions of Devs. Port has ``vector<Port*> ToP'' as a set of successors as well as ``vector<Port*> FromP'' as a set of predecessors which are changed when we call AddCP() and RemoveCP() of Coupled.

InputPort and OutputPort are concrete and derived classes from Port.