Implementing the copy constructor in terms of operator=

Question

If the operator= is properly defined, is it OK to use the following as copy constructor?

MyClass::MyClass(MyClass const &_copy)
{
    *this          


        

Answer 1

It is technically OK, if you have a working assignment operator (copy operator).

However, you should prefer copy-and-swap because:

• Exception safety is easier with copy-swap
• Most logical separation of concerns:
  • The copy-ctor is about allocating the resources it needs (to copy the other stuff).
  • The swap function is (mostly) only about exchanging internal "handles" and doesn't need to do resource (de)allocation
  • The destructor is about resource deallocation
  • Copy-and-swap naturally combines these three function in the assignment/copy operator