Invoke a c++ class method without a class instance?

Question

Is it possible to invoke a c++ class method without first creating a class instance?

Suppose we have the following code:

// just an example  #include <iostream> using namespace std;  class MyClass {     public:         MyClass();         ~MyClass();         int MyMethod(int *a, int *b); };  // just a dummy method int MyClass::MyMethod(int *a, int *b){;     return a[0] - b[0]; } 

---

Here's another example:

#include <iostream> using namespace std;  class MyClassAnother {     public:         MyClassAnother();         ~MyClassAnother();         int MyMethod(int *a, int *b); };  // just a dummy method int MyClassAnother::MyMethod(int *a, int *b){;     return a[0] + b[0]; } 

As we can see, in the above examples, both classes have no internal variables and use dummy constructors / destructors; Their sole purpose is to expose one public method, MyMethod(..). Here's my question: assume there are 100 such classes in the file (all with different class names, but with an identical structure -- one public method having the same prototype -- MyMethod(..).

Is there a way to invoke the MyMethod(..) method calls of each one of the classes without first creating a class instance for each?

Answer 1

Use the keyword 'static' to declare the method:

static int MyMethod( int * a, int * b ); 

Then you can call the method without an instance like so:

int one = 1; int two = 2;  MyClass::MyMethod( &two, &one ); 

'static' methods are functions which only use the class as a namespace, and do not require an instance.