[benibela]

The syntax of Rust with all the different kind of references looks far too complex, just to get a performance improvement.

Garbage collectors provide memory safety without any special syntax.

Or in Delphi all strings are reference counted. They are mutable, if the ref count is 1, and immutable when it is larger than one. It is memory safe with safe aliasing and needs no special syntax.

A sufficient smart compiler could just optimize the reference counting away, and treat everything as immutable, unless it can prove there is no aliasing. Ideally, a language would only have two kinds of reference, mutable and constant, and everything is figured out by the compiler

[iopq]

There's only one kind of reference: &T

I guess Box<T> is special-typed but at the surface it just looks like a normal type

Yes, there's also a C pointer type, but it's for interop