Question

Let say I have a basic 2D vector class something like

class vector2
{
  int x, y;
}

these two values could be used to represent a position as well as a width and height. does C++ provide a away for me to impliment a function such as vector2::getXpos() and then also define vector2::getWidth() and have it use the same implementation.

I know that I could just make both of these function inline, but the compiler might decide to not inline these functions. so if getWidth just called getXpos you would end up with two function calls.

A more relistic example of what I would want to use this for is getLength() and erm… getSpan() (thinking of like a screen here for when you say 40″ tv)

I would assume that this would be a simple case of something like a special function definition… I did find this page but this sounds like it is a C feature… and a bit of a hack to get working.

EDIT

I am not asking about the mechanics of inline functions… I basicaly want to do something functionally like

class MyClass
{
  void ActaullyDoStuff();
  public:
  void foo(){ActaullyDoStuff();}
  void bar(){ActuallyDoStuff();}
}

but where I can just write something like

class MyBetterClass
{
  public:
  void foo(){ /* BLOCK OF CODE */ }
  void bar(){ /* DO WHAT EVER foo() DOES */ }
}

I want bar() to be another way of just doing foo() so that the same functional code can have different, more appropriate names depending on the situation.

Answer 1

It appears you’re not thinking about this in an object oriented way. I have to second mjfgates advice that you really don’t want to do this.

What you want to do is abstract the idea of a vector into a class and implement the common methods you might want to use with a vector. In fact, you may want to consider implementing your class example above as a “Point” class and then have a “Vector” class aggregate two point classes.

Using your example, your class would not be well defined if it was used for two different purposes. Let’s say you want to make a method on some class to draw vector2. You would have to know which instances of vector2 are representing a starting point and which ones are representing a width/height. You’d probably also need a third representation to represent direction. The easier way is to implement the vector in terms of getStartPoint, getEndPoint, and any other methods that will do calculations appropriate for the vector. Then the consumer doesn’t need to know about the internal working of the vector2 class, they just call the methods to get the information they need.