What does this piece of code (circled) do?

Question

C++ / C#

What is obj? Where is this link?

Answer 1

This is the copy constructor of the myclass class, it takes as a parameter a constant reference to an instance of the myclass class. Called to create a new instance of a class based on an existing instance of the same class (copy the class).
See details and examples here: https://en.cppreference.com/w/cpp/language/copy_co...