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When is a class implicitly copied in C++?
I have a class that contains a unique_ptr, and therefore cannot be safely copied, and therefore, I disabled the copy constructor on the class by creating private versions of X(X&) and X& operator = X&.
I immediately ran into the problem that instances of this class cannot be returned, because returning actually makes a copy of the instance.
Are there any other situations I need to watch out for?
The situations that come to mind are: functions that receives the class by value, functions that returns then class by value, and any class or container that contains that class. Classes like std::vector will use move semantics whenever possible (you did overload that right)? but will be unable to use functions that require a copy constructor, such as copying the vector. As GMan said though, you can make a copy constructor for your class, and do a deep copy of the std::unique_ptr manually, if you want to make things easier.