Mnemonic for C# generic types

Question

I often forget if i have to use in or out when defining covarient and contravarient generic types. In java i have the mnemonic PECS (producer extends consumer super) to help me. Do you know a similar mnemonic for c#?

Answer 1

Didn't they do this for us when they called them 'in' and 'out' rather than covariant and contravariant? Just think: am I pushing values 'in', or getting them 'out'? If unsure, try 'out' - it is far more common (and easier to understand).

Answer 2

in types are passed in to functions; out types are returned out from functions.