When programming C++ we used to create copy constructors when needed (or so we were taught). When switching to Java a few years ago, I noticed that the Cloneable interface is now being used instead. C# followed the same route defining the ICloneable interface. It seems to me that cloning is part of the definition of OOP. But I wonder, why were these interfaces created, and the copy constructor seems to have been dropped?
When I thought about it, I came to the thought that a copy constructor would not be useful if one needs to make a copy of an object whose type is not known (as in having a reference to a base type). This seems logical. But I wonder whether there are other reasons that I do not know of, for which the Cloneable interfaces have been favored over copy constructors?