Covariance and contravariance with LSP

Question

What is the relationship between LSP and covariance and contravariance? Is there any relationship? Is LSP a form of covariance?

Answer 1

I would not say that the Liskov replacement principle is a “form” of covariance, since general covariance allows LSP to be expressed in general relations. Starting with C # 4 / .NET 4, you can consider IEnumerable<Banana>how you IEnumerable<Fruit>should be able to do this without any unpleasant surprises - this is exactly what LSP requires.