X-Git-Url: https://git.ralfj.de/rust-101.git/blobdiff_plain/83e8dbfff2a6fdce785af58dbb13f007c4234cf2..98765a4ec4731843578d0631f5a10b5d876549f2:/src/part08.rs
diff --git a/src/part08.rs b/src/part08.rs
index d6b6782..340de24 100644
--- a/src/part08.rs
+++ b/src/part08.rs
@@ -17,22 +17,22 @@ fn overflowing_add(a: u64, b: u64, carry: bool) -> (u64, bool) {
//@ 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.
//@ 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 = u64::wrapping_add(a, b);
+ let sum = a.wrapping_add(b);
// If an overflow happened, then the sum will be smaller than *both* summands. Without an overflow, of course, it will be
// at least as large as both of them. So, let's just pick one and check.
if sum >= a {
// The addition did not overflow.
// **Exercise 08.1**: Write the code to handle adding the carry in this case.
- let sum_total = u64::wrapping_add(sum, if carry { 1 } else { 0 }); /*@@*/
- let had_overflow = sum_total < sum; /*@@*/
- (sum_total, had_overflow) /*@@*/
+ let sum_total = sum.wrapping_add(if carry { 1 } else { 0 });/*@@*/
+ let had_overflow = sum_total < sum; /*@@*/
+ (sum_total, had_overflow) /*@@*/
} else {
// Otherwise, the addition *did* overflow. It is impossible for the addition of the carry
// to overflow again, as we are just adding 0 or 1.
- (sum + if carry { 1 } else { 0 }, true) /*@*/
+ (sum + if carry { 1 } else { 0 }, true) /*@*/
}
}
@@ -57,7 +57,7 @@ fn test_overflowing_add() {
impl ops::Add 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
@@ -91,13 +91,13 @@ impl ops::Add for BigInt {
}
}
-// ## 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 {
@@ -152,4 +152,4 @@ mod tests {
// **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)