Rust-Compare: a comparison of Rust, C++, and Java

In section "Interfaces"

  impl Interfaces {
    fn my_method(a: isize) -> isize {
      return a;
    }
  }

It isn't implementation of trait. It specify default implementation of trait.

It must be:

  trait Interfaces {
    fn my_method(a: isize) -> isize;
  }

  struct Impl;

  impl Interfaces for Impl {
    fn my_method(a: isize) -> isize {
      return a;
    }
  }

In section "Enums", you can apply default implementation of equality trait:

  #[derive(PartialEq, Eq)]
  enum BasicEnum {
    Option1 = 1,
    Option2
  }

and compare

    if e1 == BasicEnum::Option1 {
        e1 = BasicEnum::Option2
    }

In section "Parameters", you said "All three languages default to pass-by-value if not otherwise specified". For privitive types it's true, but it's not. Classes in Java have reference semantic (copy only address in method). Structs in Rust have move semantic witch is connacted with ownership concept (https://doc.rust-lang.org/stable/book/ownership.html).

In common, many basic things for Rust have very good descriptions in Rust Book (https://doc.rust-lang.org/stable/book/). Please, pay attension on it and be more careful.