// Struct
    struct Point {
        x: i32,
        y: i32,
    }

    let origin: Point = Point { x: 0, y: 0 };

    // A struct with unnamed fields, called a ‘tuple struct’
    struct Point2(i32, i32);

    let origin2 = Point2(0, 0);

    // Basic C-like enum
    enum Direction {
        Left,
        Right,
        Up,
        Down,
    }

    let up = Direction::Up;

    // Enum with fields
    enum OptionalI32 {
        AnI32(i32),
        Nothing,
    }

    let two: OptionalI32 = OptionalI32::AnI32(2);
    let nothing = OptionalI32::Nothing;

    // Generics //

    struct Foo<T> { bar: T }

    // This is defined in the standard library as `Option`
    enum Optional<T> {
        SomeVal(T),
        NoVal,
    }

    // Methods //

    impl<T> Foo<T> {
        // Methods take an explicit `self` parameter
        fn get_bar(self) -> T {
            self.bar
        }
    }

    let a_foo = Foo { bar: 1 };
    println!("{}", a_foo.get_bar()); // 1

    // Traits (known as interfaces or typeclasses in other languages) //

    trait Frobnicate<T> {
        fn frobnicate(self) -> Option<T>;
    }

    impl<T> Frobnicate<T> for Foo<T> {
        fn frobnicate(self) -> Option<T> {
            Some(self.bar)
        }
    }

    let another_foo = Foo { bar: 1 };
    println!("{:?}", another_foo.frobnicate()); // Some(1)