> attempting to design a new programming language without first studying carefully the history of programming Rust's original designer credits these languages

> attempting to design a new programming language without first studying carefully the history of programming Rust's original designer credits these languages as the inspiration: http://venge.net/graydon/talks/intro-talk-2.pdf http://venge.net/graydon/talks/intro-talk-2.pdf Mesa (1977), BETA (1975), CLU (1974), Nil (1981), Hermes (1990), Erlang (1987), Sather (1990), Newsqueak (1988), Alef (1995), Limbo (1996), and Napier (1985, 1988). The original Rust compiler was written in Ocaml. > has to specify whether function parameters are passed by value or by reference You specify whether arguments are borrowed or moved, and whether the access is shared or exclusive. This is not an implementation detail, it's an API contract that affects semantics of the program. It adds or removes restrictions on the caller's side, and controls memory management and thread safety. People unfamiliar with Rust very often misunderstand Rust's borrowed/owned distinction as reference/value, but in Rust these two aspects are orthogonal: Rust also has owning reference types, and borrowing types passed by copying. This misunderstanding is the major reason why novices "fight the borrow checker", because they try to avoid copying, but end up avoiding owning. There are different possible approaches to achieving similar results for argument passing, but Rust prefers to be explicit and give low-level control. For example, Mutable Value Semantics is often cited as an alternative design, but it can't express putting temporary loans in structs. The syntax needs a place to declare lifetimes (loan scopes), as otherwise implicit magic makes working with view types tricky or impossible: https://safecpp.org/draft-lifetimes.html https://safecpp.org/draft-lifetimes.html