Checked exceptions: Java’s biggest mistake (2014)(literatejava.com)

    #[must_use]
    fn get() -> i32 { 
      5
    }

    fn main() {
      get();
    }

    warning: unused return value of `get` that must be used
     --> main.rs:7:3
      |
    7 |   get();
      |   ^^^^^^
      |
      = note: `#[warn(unused_must_use)]` on by default

  private static <T extends Throwable> T sneakyThrow(Throwable ex) throws T {
     throw (T) ex;
  }

  byte[] read() throws IOException
    // vs
  Optional<byte[]> read()

  void write(byte[]) throws IOException
    // vs
  Optional<Void> write(byte[])

  val _ = write(bytes);

  write(bytes);

    public int concreteChecked() throws FileNotFound {
      if (bar) throw new FileNotFound();
      return 42;
    }

    public int polymorphicChecked() throws Exception {
      if (bar) throw new FileNotFound();
      return 42;
    }

    public Either<FileNotFound, int> concreteEither() {
      return bar? new Left(new FileNotFound()) : new Right(42);
    }

    public Either<Exception, int> polymorphicEither() {
      return bar? new Left(new FileNotFound()) : new Right(42);
    }

    public int unchecked() {
      if (bar) throw new RuntimeException(new FileNotFound());
      return 42;
    }