fix: refactor move semantics 1-4 into tests
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c177507db3
commit
51e237d5f9
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@ -5,24 +5,19 @@
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// I AM NOT DONE
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#[test]
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fn main() {
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let vec0 = Vec::new();
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let vec0 = vec![22, 44, 66];
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let vec1 = fill_vec(vec0);
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println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);
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vec1.push(88);
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println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);
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assert_eq!(vec1, vec![22, 44, 66, 88]);
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}
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fn fill_vec(vec: Vec<i32>) -> Vec<i32> {
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let mut vec = vec;
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let vec = vec;
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vec.push(22);
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vec.push(44);
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vec.push(66);
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vec.push(88);
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vec
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}
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@ -1,32 +1,26 @@
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// move_semantics2.rs
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//
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// Expected output:
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// vec0 has length 3, with contents `[22, 44, 66]`
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// vec1 has length 4, with contents `[22, 44, 66, 88]`
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// Make the test pass by finding a way to keep both Vecs separate!
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//
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// Execute `rustlings hint move_semantics2` or use the `hint` watch subcommand
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// for a hint.
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// I AM NOT DONE
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#[test]
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fn main() {
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let vec0 = Vec::new();
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let vec0 = vec![22, 44, 66];
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let mut vec1 = fill_vec(vec0);
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println!("{} has length {}, with contents: `{:?}`", "vec0", vec0.len(), vec0);
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vec1.push(88);
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println!("{} has length {}, with contents `{:?}`", "vec1", vec1.len(), vec1);
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assert_eq!(vec0, vec![22, 44, 66]);
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assert_eq!(vec1, vec![22, 44, 66, 88]);
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}
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fn fill_vec(vec: Vec<i32>) -> Vec<i32> {
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let mut vec = vec;
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vec.push(22);
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vec.push(44);
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vec.push(66);
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vec.push(88);
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vec
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}
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@ -8,22 +8,17 @@
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// I AM NOT DONE
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#[test]
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fn main() {
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let vec0 = Vec::new();
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let vec0 = vec![22, 44, 66];
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let mut vec1 = fill_vec(vec0);
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println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);
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vec1.push(88);
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println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);
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assert_eq!(vec1, vec![22, 44, 66, 88]);
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}
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fn fill_vec(vec: Vec<i32>) -> Vec<i32> {
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vec.push(22);
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vec.push(44);
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vec.push(66);
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vec.push(88);
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vec
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}
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@ -9,25 +9,21 @@
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// I AM NOT DONE
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#[test]
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fn main() {
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let vec0 = Vec::new();
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let vec0 = vec![22, 44, 66];
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let mut vec1 = fill_vec(vec0);
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println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);
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vec1.push(88);
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println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);
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assert_eq!(vec1, vec![22, 44, 66, 88]);
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}
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// `fill_vec()` no longer takes `vec: Vec<i32>` as argument
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// `fill_vec()` no longer takes `vec: Vec<i32>` as argument - don't change this!
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fn fill_vec() -> Vec<i32> {
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// Instead, let's create and fill the Vec in here - how do you do that?
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let mut vec = vec;
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vec.push(22);
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vec.push(44);
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vec.push(66);
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vec.push(88);
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vec
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}
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16
info.toml
16
info.toml
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@ -284,9 +284,9 @@ better. What do you think is the more commonly used pattern under Rust developer
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[[exercises]]
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name = "move_semantics1"
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path = "exercises/move_semantics/move_semantics1.rs"
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mode = "compile"
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mode = "test"
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hint = """
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So you've got the "cannot borrow immutable local variable `vec1` as mutable" error on the line
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So you've got the "cannot borrow immutable local variable `vec` as mutable" error on the line
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where we push an element to the vector, right?
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The fix for this is going to be adding one keyword, and the addition is NOT on the line where
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we push to the vector (where the error is).
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@ -296,7 +296,7 @@ Also: Try accessing `vec0` after having called `fill_vec()`. See what happens!""
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[[exercises]]
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name = "move_semantics2"
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path = "exercises/move_semantics/move_semantics2.rs"
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mode = "compile"
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mode = "test"
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hint = """
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When running this exercise for the first time, you'll notice an error about
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"borrow of moved value". In Rust, when an argument is passed to a function and
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@ -309,16 +309,12 @@ Rust provides a couple of different ways to mitigate this issue, feel free to tr
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2. Make `fill_vec` borrow its argument instead of taking ownership of it,
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and then copy the data within the function (`vec.clone()`) in order to return an owned
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`Vec<i32>`.
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3. Or, you could make `fill_vec` *mutably* borrow a reference to its argument (which will need to be
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mutable), modify it directly, then not return anything. This means that `vec0` will change over the
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course of the function, and makes `vec1` redundant (make sure to change the parameters of the `println!`
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statements if you go this route)
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"""
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[[exercises]]
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name = "move_semantics3"
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path = "exercises/move_semantics/move_semantics3.rs"
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mode = "compile"
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mode = "test"
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hint = """
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The difference between this one and the previous ones is that the first line
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of `fn fill_vec` that had `let mut vec = vec;` is no longer there. You can,
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@ -328,7 +324,7 @@ an existing binding to be a mutable binding instead of an immutable one :)"""
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[[exercises]]
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name = "move_semantics4"
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path = "exercises/move_semantics/move_semantics4.rs"
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mode = "compile"
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mode = "test"
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hint = """
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Stop reading whenever you feel like you have enough direction :) Or try
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doing one step and then fixing the compiler errors that result!
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@ -337,7 +333,7 @@ So the end goal is to:
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- so then `vec0` doesn't exist, so we can't pass it to `fill_vec`
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- `fill_vec` has had its signature changed, which our call should reflect
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- since we're not creating a new vec in `main` anymore, we need to create
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a new vec in `fill_vec`, similarly to the way we did in `main`"""
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a new vec in `fill_vec`, and fill it with the expected values"""
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[[exercises]]
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name = "move_semantics5"
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