To convert one type into another, we have the From and Into traits. The interesting part about both of these traits is that we only need to implement the From trait and we get the implementation of the Into trait for free, because of the following impl:

#[stable(feature = "rust1", since = "1.0.0")]
impl<T, U> Into<U> for T where U: From<T> {
    fn into(self) -> U {
        U::from(self)
    }
}