I recently have been reading about move constructors in C++ (see e.g. here) and I am trying to understand how they work and when I should use them.

As far as I understand, a move constructor is used to alleviate the performance problems caused by copying large objects. The wikipedia page says: "A chronic performance problem with C++03 is the costly and unnecessary deep copies that can happen implicitly when objects are passed by value."

I normally address such situations

• by passing the objects by reference, or
• by using smart pointers (e.g. boost::shared_ptr) to pass around the object (the smart pointers get copied instead of the object).

What are the situations in which the above two techniques are not sufficient and using a move constructor is more convenient?