X-Git-Url: https://git.ralfj.de/rust-101.git/blobdiff_plain/f212d116773ee38f4e8a6b18c3aaa3869472de7b..a3a64118702b4f75691de78d42256c306f286014:/workspace/src/part08.rs diff --git a/workspace/src/part08.rs b/workspace/src/part08.rs index 61f665f..5ddcb33 100644 --- a/workspace/src/part08.rs +++ b/workspace/src/part08.rs @@ -7,7 +7,7 @@ use part05::BigInt; // So, let us write a function to "add with carry", and give it the appropriate type. Notice Rust's native support for pairs. fn overflowing_add(a: u64, b: u64, carry: bool) -> (u64, bool) { - 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 { @@ -56,11 +56,11 @@ impl ops::Add for BigInt { } } -// ## Traits and borrowed types +// ## Traits and reference types // 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 { @@ -76,7 +76,9 @@ impl<'a, 'b> ops::Add<&'a BigInt> for &'b BigInt { // Rust calls a bunch of definitions that are grouped together a *module*. You can put the tests in a submodule as follows. #[cfg(test)] mod tests { - #[test] + use part05::BigInt; + + /*#[test]*/ fn test_add() { let b1 = BigInt::new(1 << 32); let b2 = BigInt::from_vec(vec![0, 1]);