I have one abstract Shape class. Different Line, Curve, Rectangle, Square classes are derived from Shape.
one variable List<Shape> is storing different objects of these classes.
Writing this variable to a file is straight forward.
But, reading from file to fill this variable needs to know what kind of class is going to be read next. So, some signature should be written in the file appriory .....
If any standard technique is available for serialization for inheritance.