If you have a struct of type T and an instance of that struct t, you can create a new instance using the syntax T { ..t } which means "a new T with all the

If you have a struct of type T and an instance of that struct t, you can create a new instance using the syntax T { ..t } which means "a new T with all the fields set to their values in t". Inside the trait "Self" is an alias for "Number". "&self" is shorthand for "self: &Number", i.e., a reference to Number. To dereference a reference, prefix with * So: self has type "&Number" and *self has type "Number". Thus, Self { ..*self } is creating a new instance of Number with its each set to the same value as self. Disclaimer! everything I know about rust I learned 2 days ago from this blog post, so I might be wrong :-)