Rust has two parents; it got its looks from C, but much of its character was inherited from its other, less commonly mentioned parent -- ML. Rust has a variation of the Hindley-Milner type system, quite similar to ML (or Haskell). Rust's enum and struct are algebraic data types, also known as sum or product records or types. The type system and pattern matching enable declarative and functional styles of programming that are much less natural to express in C.