X-Git-Url: https://git.ralfj.de/rust-101.git/blobdiff_plain/87eef0eb20858188744e529fb0c5f1282577b8e4..177a1f127af6601f373be9742c31351f556633ab:/src/part01.rs diff --git a/src/part01.rs b/src/part01.rs index 7603c1f..1603c14 100644 --- a/src/part01.rs +++ b/src/part01.rs @@ -34,16 +34,10 @@ fn number_or_default(n: NumberOrNothing, default: i32) -> i32 { } } -// With this fresh knowledge, let us now refactor `vec_min`. First of all, we are doing a small change -// to the type: `&Vec` denotes a *reference* to a `Vec`. You can think of this as a pointer -// (in C terms): Arguments in Rust are passed *by value*, so we need to employ explicit references if -// that's not what we want. References are per default immutable (like variables), a mutable reference -// would be denoted `&mut Vec`. -fn vec_min(v: &Vec) -> NumberOrNothing { +// With this fresh knowledge, let us now refactor `vec_min`. +fn vec_min(v: Vec) -> NumberOrNothing { let mut min = Nothing; for e in v { - // Now that `v` is just a reference, the same goes for `e`, so we have to dereference the pointer. - let e = *e; // Notice that all we do here is compute a new value for `min`, and that it will always end // up being a `Number` rather than `Nothing`. In Rust, the structure of the code // can express this uniformity. @@ -85,15 +79,16 @@ impl NumberOrNothing { fn read_vec() -> Vec { vec![18,5,7,2,9,27] } -pub fn part_main() { +pub fn main() { let vec = read_vec(); - let min = vec_min(&vec); + let min = vec_min(vec); min.print(); } // You will have to replace `part00` by `part01` in the `main` function in // `main.rs` to run this code. // **Exercise**: Write a funtion `vec_avg` that computes the average value of a `Vec`. +// // *Hint*: `vec.len()` returns the length of a vector `vec`. // [index](main.html) | [previous](part00.html) | [next](part02.html)