1. Erase Types

We already saw this, but it is worth mentioning again. One reason why keypaths are so useful is because there're type-erased variants. As we saw in our practical example, the ability to temporarily go to AnyKeyPath offers many more opportunities. So, always remember these types:

KeyPath<A, B> = \User.age

PartialKeyPath<A> = \User.age

AnyKeyPath = \User.age