How can a class's memory-allocated address be determined from within the contructor?

Question

Is it possible to get the memory-allocated address of a newly instantiated class from within that class's constructor during execution of said constructor? I am developing a linked list wherein multiple classes have multiple pointers to like classes. Each time a new class instantiates, it needs to check its parent's list to make sure it is included.

If I try to do something like this:

MyClass() // contructor
{
   extern MyClass * pParent;

   for ( int i = 0; i < max; i++ )
   {
      pParent->rels[i] == &MyClass; // error
   }
}

I get this error:

error C2275: 'namespace::MyClass' : illegal use of this type as an expression

Any thoughts or suggestions would be appreciated. Thanks.

Answer 1

Did you mean to do:

pParents->rels[i] = this;

Answer 2

You are looking for this.

Answer 3

If You write an instance method like for example:

void MyClass::foo(some params);

the compiler adds a special parameter to the method by which an address of an instance is passed. You can imagine that instead of a signature above, the compiler creates something like this:

//this is pseudocode
void MyClass::foo(MyClass * const this, some params);

This is one of the reasons, why for example You cant pass instance methods directly as callbacks.

In the body of any instance method, You can use a special keyword this as a const pointer to the instance.

Static methods don't get that pointer so You can't use this keyword in their definitions.

If You create a const method like like:

class MyClass
{
    void foo(some params);
    void foo(some params) const;
}

it is like there was a second method

//this is pseudocode
void MyClass::foo(const MyClass * const this, some params);

and the compiler can make an overload resolution based on the constness of the the object for which the method is called