X-Git-Url: https://git.ralfj.de/rust-101.git/blobdiff_plain/ee5a849f625d3bd9bd9bb661428d1c051f285ebe..e73ddf5e1d4768cb86fba3eb583f4fec0286acff:/src/part08.rs diff --git a/src/part08.rs b/src/part08.rs index cacff46..feb2abc 100644 --- a/src/part08.rs +++ b/src/part08.rs @@ -28,7 +28,7 @@ fn overflowing_add(a: u64, b: u64, carry: bool) -> (u64, bool) { // **Exercise 08.1**: Write the code to handle adding the carry in this case. unimplemented!() } else { - // The addition *did* overflow. It is impossible for the addition of the carry + // 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) /*@*/ } @@ -101,6 +101,8 @@ impl<'a, 'b> ops::Add<&'a BigInt> for &'b BigInt { } } +// **Exercise 08.4**: Implement the two missing combinations of arguments for `Add`. You should not have to duplicate the implementation. + // ## Modules //@ As you learned, tests can be written right in the middle of your development in Rust. However, it is //@ considered good style to bundle all tests together. This is particularly useful in cases where @@ -117,7 +119,7 @@ mod tests { let b2 = BigInt::from_vec(vec![0, 1]); assert_eq!(&b1 + &b2, BigInt::from_vec(vec![1 << 32, 1])); - // **Exercise 08.4**: Add some more cases to this test. + // **Exercise 08.5**: Add some more cases to this test. } } //@ As already mentioned, outside of the module, only those items declared public with `pub` may be used. Submodules can access @@ -140,7 +142,7 @@ mod tests { //@ from other files. This ensures that the directory structure mirrors the structure of the modules, with `mod.rs`, `lib.rs` //@ and `main.rs` representing a directory or crate itself (similar to, e.g., `__init__.py` in Python). -// **Exercise 08.4**: Write a subtraction function, and testcases for it. Decide for yourself how you want to handle negative results. +// **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](main.html) +//@ [index](main.html) | [previous](part07.html) | [next](part09.html)