IMO both language types offer shared state and immutable data structures so I don't see them as mutually exclusive. As the Rust guys I've heard say "sharing sta

IMO both language types offer shared state and immutable data structures so I don't see them as mutually exclusive. As the Rust guys I've heard say "sharing state and mutation are fine, just not together". It's a question of whether the problem your trying to solve is better as a highly mutable one with "sharing" (e.g I'm thinking system programming with contended system resources) or you want to share data across many threads simultaneously and are happy with slower single threaded performance for greater multi threaded throughput (writes are rare so sharing and locking on an atomic ref on occasion is OK so you want structural sharing of data). Rust helps the coder avoid the issues when coding in the traditional "sharing and mutation" paradigm especially without a GC; languages like F# have some modern things to do this like atomic refs for data sharing, flagging mutables, async lock types, support for imperative programming etc. Both approaches work and IMO suit different kinds of problems; good to have both available.