Overloading class member access (C++ only)

You overload operator-> with a nonstatic member function that has no parameters. The following example demonstrates how the compiler interprets overloaded class member access operators:

struct Y {
  void f() { };
};

struct X {
 Y* ptr;
 Y* operator->() {
   return ptr;
 };
};

int main() {
  X x;
  x->f();
}

The statement x->f() is interpreted as (x.operator->())->f().

The operator-> is used (often in conjunction with the pointer-dereference operator) to implement "smart pointers." These pointers are objects that behave like normal pointers except they perform other tasks when you access an object through them, such as automatic object deletion (either when the pointer is destroyed, or the pointer is used to point to another object), or reference counting (counting the number of smart pointers that point to the same object, then automatically deleting the object when that count reaches zero).

One example of a smart pointer is included in the C++ Standard Library called auto_ptr. You can find it in the <memory> header. The auto_ptr class implements automatic object deletion.

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