//@ The reason for this is that many serious security vulnerabilities have been caused by integer overflows, so just assuming
//@ "per default" that they are intended is dangerous. <br/>
//@ If you explicitly *do* want an overflow to happen, you can call the `wrapping_add`
- //@ function (see [the documentation](http://doc.rust-lang.org/stable/std/primitive.u64.html#method.wrapping_add),
+ //@ function (see [the documentation](https://doc.rust-lang.org/stable/std/primitive.u64.html#method.wrapping_add),
//@ there are similar functions for other arithmetic operations). There are also similar functions
//@ `checked_add` etc. to enforce the overflow check.
let sum = a.wrapping_add(b);
impl ops::Add<BigInt> for BigInt {
//@ Besides static functions and methods, traits can contain *associated types*: This is a type chosen by every particular implementation
//@ of the trait. The methods of the trait can then refer to that type. In the case of addition, it is used to give the type of the result.
- //@ (Also see the [documentation of `Add`](http://doc.rust-lang.org/stable/std/ops/trait.Add.html).)
+ //@ (Also see the [documentation of `Add`](https://doc.rust-lang.org/stable/std/ops/trait.Add.html).)
//@
//@ In general, you can consider the two `BigInt` given above (in the `impl` line) *input* types of trait search: When
//@ `a + b` is invoked with `a` having type `T` and `b` having type `U`, Rust tries to find an implementation of `Add` for
}
}
-// ## Traits and borrowed types
+// ## Traits and reference types
//@ If you inspect the addition function above closely, you will notice that it actually consumes ownership of both operands
//@ to produce the result. This is, of course, in general not what we want. We'd rather like to be able to add two `&BigInt`.
// Writing this out becomes a bit tedious, because trait implementations (unlike functions) require full explicit annotation
// of lifetimes. Make sure you understand exactly what the following definition says. Notice that we can implement a trait for
-// a borrowed type!
+// a reference type!
impl<'a, 'b> ops::Add<&'a BigInt> for &'b BigInt {
type Output = BigInt;
fn add(self, rhs: &'a BigInt) -> Self::Output {
// **Exercise 08.6**: Write a subtraction function, and testcases for it. Decide for yourself how you want to handle negative results.
// For example, you may want to return an `Option`, to panic, or to return `0`.
-//@ [index](main.html) | [previous](part07.html) | [next](part09.html)
+//@ [index](main.html) | [previous](part07.html) | [raw source](https://www.ralfj.de/git/rust-101.git/blob_plain/HEAD:/workspace/src/part08.rs) | [next](part09.html)