//@ `SomethingOrNothing<i32>` to get back our `NumberOrNothing`.
type NumberOrNothing = SomethingOrNothing<i32>;
//@ However, we can also write `SomethingOrNothing<bool>` or even `SomethingOrNothing<SomethingOrNothing<i32>>`.
-//@ In fact, such a type is so useful that it is already present in the standard library: It's called an
+//@ In fact, a type like `SomethingOrNothing` is so useful that it is already present in the standard library: It's called an
//@ *option type*, written `Option<T>`. Go check out its [documentation](https://doc.rust-lang.org/stable/std/option/index.html)!
-//@ (And don't worry, there's indeed lots of material mentioned there that we did not cover yet.)
+//@ (And don't worry, there's indeed lots of material mentioned there that we have not covered yet.)
// ## Generic `impl`, Static functions
//@ The types are so similar, that we can provide a generic function to construct a `SomethingOrNothing<T>`
}
// ## Traits
-//@ Now that we have a generic `SomethingOrNothing`, wouldn't it be nice to also gave a generic
+//@ Now that we have a generic `SomethingOrNothing`, wouldn't it be nice to also have a generic
//@ `vec_min`? Of course, we can't take the minimum of a vector of *any* type. It has to be a type
//@ supporting a `min` operation. Rust calls such properties that we may demand of types *traits*.
//@ For now, just ignore the `Copy`, we will come back to this point later.
//@ A `trait` is a lot like interfaces in Java: You define a bunch of functions
//@ you want to have implemented, and their argument and return types. <br/>
-//@ The function `min` takes to arguments of the same type, but I made the
+//@ The function `min` takes two arguments of the same type, but I made the
//@ first argument the special `self` argument. I could, alternatively, have
//@ made `min` a static function as follows: `fn min(a: Self, b: Self) -> Self`.
-//@ However, in Rust one typically prefers methods over static function wherever possible.
+//@ However, in Rust one typically prefers methods over static functions wherever possible.
pub trait Minimum : Copy {
fn min(self, b: Self) -> Self;
}
//@ Before going on, take a moment to ponder the flexibility of Rust's take on abstraction:
//@ We just defined our own, custom trait (interface), and then implemented that trait
//@ *for an existing type*. With the hierarchical approach of, e.g., C++ or Java,
-//@ that's not possible: We cannot make an existing type suddenly also inherit from our abstract base class.
+//@ that's not possible: We cannot make an existing type also inherit from our abstract base class after the fact.
//@
//@ In case you are worried about performance, note that Rust performs *monomorphisation*
//@ of generic functions: When you call `vec_min` with `T` being `i32`, Rust essentially goes