What are the pointer-to-member operators ->* and .* in C++?

by

I hope this example will clear things for you

//we have a class
struct X
{
   void f() {}
   void g() {}
};

typedef void (X::*pointer)();
//ok, let's take a pointer and assign f to it.
pointer somePointer = &X::f;
//now I want to call somePointer. But for that, I need an object
X x;
//now I call the member function on x like this
(x.*somePointer)(); //will call x.f()
//now, suppose x is not an object but a pointer to object
X* px = new X;
//I want to call the memfun pointer on px. I use ->*
(px ->* somePointer)(); //will call px->f();

Now, you can’t use x.somePointer(), or px->somePointer() because there is no such member in class X. For that the special member function pointer call syntax is used… just try a few examples yourself ,you’ll get used to it

More Related Contents:

  1. Difference between this. and this->
  2. What are the basic rules and idioms for operator overloading?
  3. What is the difference between the dot (.) operator and -> in C++? [duplicate]
  4. How can I pass a member function where a free function is expected?
  5. What does the question mark character (‘?’) mean in C++?
  6. Implementing comparison operators via ‘tuple’ and ‘tie’, a good idea?
  7. Why don’t C++ compilers define operator== and operator!=?
  8. C++ [] array operator with multiple arguments?
  9. Overloading friend operator
  10. What does the >?= operator mean?
  11. Making operator
  12. How to hash and compare a pointer-to-member-function?
  13. Can you make custom operators in C++?
  14. The copy constructor and assignment operator
  15. The tilde operator in C
  16. Operator Overloading in C++ as int + obj
  17. Why does the expression a = a + b – ( b = a ) give a sequence point warning in c++?
  18. Pointers to members representations
  19. Casting between void * and a pointer to member function
  20. What is the value category of the operands of C++ operators when unspecified?
  21. Print address of virtual member function
  22. How Can I Pass a Member Function to a Function Pointer?
  23. C++ inheritance and member function pointers
  24. Pointers to virtual member functions. How does it work?
  25. How to print member function address in C++
  26. Two ‘==’ equality operators in same ‘if’ condition are not working as intended
  27. Are pointers to non-static member function “formally” not considered pointers
  28. What is the difference between “::” “.” and “->” in c++ [duplicate]
  29. What does ‘**’ mean in C?
  30. Why use ++i instead of i++ in cases where the value is not used anywhere else in the statement?

Leave a Comment