That would still fall under the umbrella of "type inference" If you want to learn more about this, the Damas Milner unification-based algorithm used in ML, Has

That would still fall under the umbrella of "type inference" If you want to learn more about this, the Damas Milner unification-based algorithm used in ML, Haskell and others is a must-read starting point. It does global type inference of all types in the program without requiring any annotations, by analyzing how the types are used. It also can detect when a variable is only passed around, without being used in primitive operations, in which case it infers a generic/parametric type for it.