When do you call copy constructors?

Copy Constructor:  It is a constructor, which initializes it's object member variable with another object of the same class. If you don't implement a copy constructor in your class, the compiler automatically does it.

Copy constructors are called in these situations: 

i.)when compiler generates a temporary object 
ii.)when a function returns an object of that class by value 
iii.)when the object of that class is passed by value as an argument to a function 
iv.)when you construct an object based on another object of the same class