Generic Constraints

A generic type parameter without constraints is almost useless inside the method body. You can't call Compare, you can't write new T(), you can't even call .Length. Constraints are the where clauses that tell the compiler "this T is at least this kind of thing", which unlocks the operations that kind of thing supports. This lesson covers every standard constraint, what each one unlocks, the rules for combining them, and the compiler errors that show up when you get them wrong.