Rust is very advanced, with things like higher-ranked trait bounds (https://doc.rust-lang.org/nomicon/hrtb.html https://doc.rust-lang.org/nomicon/hrtb.html) and

Rust is very advanced, with things like higher-ranked trait bounds (https://doc.rust-lang.org/nomicon/hrtb.html https://doc.rust-lang.org/nomicon/hrtb.html) and generic associated types (https://www.ncameron.org/rfcs/1598 https://www.ncameron.org/rfcs/1598) that are difficult because they are essential complexity not accidental complexity.