Chapter III Function Member
1.1. Three call modes of member functions
1.1.1. Non-static member functions
The efficiency of non-static member functions is the same, that is,
FLOAT MAGNITUDE (Const Point3D * _THIS) {...};
with
FLOAT POINT3D :: Magnitude () Const {...};
The efficiency is the same.
The conversion step of the member function is as follows (the work made by the compiler):
l Rewriting function prototype
// Non-static member function
Point3d :: Magnitude (Point3D * const this);
// constant non-static member function
Point3D :: Magnitude (const point3d * const this);
l Conversion to non-static data members is completed by the THIS pointer
{THIS-> xxxx}
l Remove the member function as an external function, process the function name, so that it is unique in the program
1.1.2. Virtual member function
l calls through the pointer
Point3D * PTR;
......
Ptr-> normalize ();
It will be converted to (* PTR-> VPTR [1]) (PTR) internally;
l Call via object
Point3D Obj;
Obj.Normalize ();
Since the compiler can determine that the call is definitely Point3D :: Normalize (), such a call will be converted to:
Normalize_7point3DEV (& obj); // The encoded function name maintains uniqueness throughout the program.
1.1.3. Static member function
Point3D * PTR;
......
Point3D Obj;
Ptr-> normalize ();
Obj.Normalize ();
It will be converted to Normalize_7Point3DEV () inside.
The main feature of the static member function is that there is no THIS pointer, followed by the second
1. Unable to access non-statist members in CLASS
2. Can't be declared as const, volatile or vitrual
You can call it without Class Object
