There is an interesting claim about Rust: > However, it prevents you from writing generic macros that use any l-value – we can’t write swap!(x[0], x[1]) as we

There is an interesting claim about Rust: > However, it prevents you from writing generic macros that use any l-value – we can’t write swap!(x[0], x[1]) as we could in Common Lisp. As long as `macro_rules!` has existed (I could be wrong about before 0.8 though), you can wrote a macro that takes any expression, and will error from the assignment when the expression is not an lvalue: macro_rules! swap { ($x:expr, $y:expr) => ({ let tmp = $x; $x = $y; $y = tmp; }) }