Variance: Covariance, Contravariance, Invariance
Variance is one of those type system concepts that developers encounter constantly but rarely name explicitly. Every time you’ve wondered why you can’t assign a List<String> to a List<Object> in…
Contravariance
TypeScript Variance: Covariance and Contravariance
Variance describes how subtyping relationships between types transfer to their generic containers. When you have a type hierarchy like Labrador extends Dog extends Animal, it’s intuitive that you…