Would passing an object to a member function or a constructor be a good use for explicitly using a this pointer?

Question

Would passing an object to a member function or a constructor be a good use of explicitly using a this pointer? such as a pass by reference?

 class Something
{
private:
    int m_data;

public:
    Something(int data ->&obj)
    {
        this->data = m_data;
    }
};

It is useful whenever it is required. When you face that problem, you'll find out. — DeiDei, May 01 '18 at 21:19
You mean this? https://stackoverflow.com/questions/16492736/what-is-the-this-pointer — Vamsidhar Reddy Gaddam, May 01 '18 at 21:19
The question marked as duplicate is only *half* the answer. The other half is when you need to assign or pass a pointer to the current object. — Mark Ransom, May 01 '18 at 21:21
@KillzoneKid no, not too broad at all. It's only slightly broader than the question about when to use `this->`. — Mark Ransom, May 01 '18 at 21:22
Consider a class such as Point with a function such as circle(int radius) that makes and returns a new Circle class. The Circle object needs to be told about where its centre is. How would you pass the central Point to the new Circle? — arnt, May 02 '18 at 10:16

score 1 · Accepted Answer · answered May 01 '18 at 21:31

When is using the “this pointer” useful in a C++ program

When you need a pointer to the current object.

One of the most often usages of this that I have seen is to make self assignment a noop.

Foo& Foo::operator=(Foo const& rhs)
{
   if ( this != &rhs )
   {
      // Assign only when the objects are different
   }
   return *this;
}

I haven't seen this as much but you can do the same simplification for operator==.

bool Foo::operator==(Foo const& rhs) const
{
   if ( this == &rhs )
   {
      return true;
   }

   // Do the real work for objects that are different.
   // ...
}

Would passing an object to a member function or a constructor be a good use for explicitly using a this pointer?

1 Answers1