C#’s generic types are, by default, invariant. Special cases of covariant and contravariant can be defined though. So what does that previous gobbledygook even mean? Hopefully this three-part article will help explain these three terms, and why they even exist in the first place.

The second part of this series, looks at what is probably the least well understood of the three terms: contravariance. If you feel you understand the other two terms, feel free to jump straight to that part therefore. The third, and last, part, looks at covariance and finishes with a summary of the difference between the three. But first, we start at the beginning: invariance.

Continue reading “Generic variance in C#, part 1 — Invariance” →