Remove move_semantics4, add rest of move_semantics solutions

exercises/06_move_semantics/move_semantics5.rs

@@ -1,21 +1,22 @@
-// Make me compile only by reordering the lines in the test, but without adding,
-// changing or removing any of them.
+// TODO: Fix the compiler erros. Don't change anything except adding or removing
+// references (the character `&`).
 
 fn main() {
-    // You can optionally experiment here.
+    let data = "Rust is great!".to_string();
+
+    get_char(data);
+
+    string_uppercase(&data);
 }
 
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn move_semantics5() {
-        let mut x = 100;
-        let y = &mut x;
-        let z = &mut x;
-        *y += 100;
-        *z += 1000;
-        assert_eq!(x, 1200);
-    }
+// Shouldn't take ownership
+fn get_char(data: String) -> char {
+    data.chars().last().unwrap()
+}
+
+// Should take ownership
+fn string_uppercase(mut data: &String) {
+    data = &data.to_uppercase();
+
+    println!("{data}");
 }