Nah, you can totally use things like holes or undefined (in haskell), unimplemented!() in rust, etc. EDIT: and, as neighbour says, any in typescript ! But type

Nah, you can totally use things like holes or undefined (in haskell), unimplemented!() in rust, etc. EDIT: and, as neighbour says, any in typescript ! But typescript, with its progressive typing, is in a league of its own.