C# in Depth

Jon Skeet

December 31, 2014

REPL—a read, evaluate, print loop.

December 31, 2014

Contravariance is the opposite way around. It’s about values being passed into the API by the caller: the API is consuming the values instead

December 31, 2014

Covariance is all about values being returned from an operation back to the caller.

December 31, 2014

In essence, variance is about being able to use an object of one type as if it were another, in a type-safe way. You’re used to variance in terms of normal inheritance: if a method has a declared return type of Stream, you can return a MemoryStream from the implementation, for example. Generic