Another use case for dynamic typing is for virtual methods that experience a problem with covariance or contravariance. One such example is the infamous Clone method that returns an object of the same type as the object it is called on. This problem is not completely solved with a dynamic return because it bypasses static type checking, but at least you don't need to use ugly casts all the time as per when using plain object. Otherwise to say, the casts become implicit.
public class A
{
// attributes and constructor here
public virtual dynamic Clone()
{
var clone = new A();
// Do more cloning stuff here
return clone;
}
}
public class B : A
{
// more attributes and constructor here
public override dynamic Clone()
{
var clone = new B();
// Do more cloning stuff here
return clone;
}
}
public class Program
{
public static void Main()
{
A a = new A().Clone(); // No cast needed here
B b = new B().Clone(); // and here
// do more stuff with a and b
}
}