Working with classes

[Arcand]

So, im relatively new to programming, and I have a tutor that has given me an assignment based on our last lesson but I have run in to a problem with something that I dont understand based on the following code:

enum OBJECT_TYPE // Creation of a data type
{
	// Individual data types
	OT_ROOM,
	OT_TOOL,
	OT_PUZZLE,
	OT_NOUN,
	OT_VERB,
	OT_MAX_OBJECT_TYPE
};

class OBJECT_ID // Class to call when using an object from OBJECT_TYPE
{
public: // Seen and used by any outside source
	OBJECT_ID() // Default constructor - Called if nothing else can be
	{
		type_of_object = OT_MAX_OBJECT_TYPE; // Makes type_of_object (as in private) the value of OT_MAX_OBJECT_TYPE, or the max and illigitimate value
	}
	OBJECT_ID(OBJECT_TYPE intype) // Primary constructor - called when requested with a defining value from the enum
	{
		type_of_object = intype; // Assigns type_of_object the value sent to the class when it was called
		
	}
	~OBJECT_ID(); // Destroys the object
private: // seen only by the class itself
	OBJECT_TYPE type_of_object; // Declares an enum value called type_of_object
};

class TOOL : public OBJECT_ID // A class that interacts with the OBJECT_ID class as its parent
{
public: // Seen and used by any outside source
	TOOL() : OBJECT_ID(OT_TOOL) // Default constructor called by OBJECT_ID with a value of OT_TOOL
	{

	}
	~TOOL();
private: // seen by only the class itself 

What im TRYING to do is have it be possible for OBJECT_ID to identify for what enum value its been called for and run the appropriate class as such, but, I just realised (the next day after the lesson... lol) that I never asked how one class can point to running code from another?

	TOOL() : OBJECT_ID(OT_TOOL) // Default constructor called by OBJECT_ID with a value of OT_TOOL 

as far as I know this line does what I commented it as, and if im not wrong then there needs to be another line of code to make this one happen?

thanks for the help!
AJ

[drognisep]

Perhaps you could accept a pointer input in a member funtion that dynamically allocates a class (of the given type) for you and returns the pointer pointing to the new class of the type specified. Make sure you don't leave a hanging pointer though.

[BlackSheep]

You want OBJECT_ID to identify the enum when it acts as a base class for TOOL? Or when you construct just the OBJECT_ID class?
Passing a value to the constructor of a parent class in the constructor list will construct that class with those parameters.

class A
{
public:
	A(int i): I(i){};
private:
	int I;
};

class B: public A
{
public:
	B(int i): A(i){};
}

int main()
{
B b(10); //I in A will take on the value 10.
}

[IkeArrumba]

I'm not exactly sure of what you are asking, but I think you may be thinking of these class definitions like functions. OBJECT_ID is a class definition; like int, or long. It is an object type. TOOL is also an object type which contains OBJECT_ID. When you create an instance of TOOL (like creating an int variable), it passes the enum value OT_TOOL (equal to 1) to the base class OBJECT_ID and it is stored as the property type_of_object. So if you have code like this:

TOOL Mytool;
printf("Mytool type is %d", Mytool.type_of_object);

You create an instance of TOOL and it knows what type it is.
As it is, this is all that Mytool can do.