traits and lifetimes

exercises/14_generics/generics2.rs

@@ -6,8 +6,6 @@
 // Execute `rustlings hint generics2` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 struct Wrapper<T> {
     value: T,
 }

exercises/15_traits/traits1.rs

@@ -7,14 +7,14 @@
 // Execute `rustlings hint traits1` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 trait AppendBar {
     fn append_bar(self) -> Self;
 }
 
 impl AppendBar for String {
-    // TODO: Implement `AppendBar` for type `String`.
+    fn append_bar(self) -> Self {
+        format!("{self}Bar").to_string()
+    }
 }
 
 fn main() {
@@ -34,9 +34,6 @@ mod tests {
 
     #[test]
     fn is_bar_bar() {
-        assert_eq!(
-            String::from("").append_bar().append_bar(),
-            String::from("BarBar")
-        );
+        assert_eq!(String::from("").append_bar().append_bar(), String::from("BarBar"));
     }
 }

exercises/15_traits/traits2.rs

@@ -8,13 +8,16 @@
 //
 // Execute `rustlings hint traits2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 trait AppendBar {
     fn append_bar(self) -> Self;
 }
 
-// TODO: Implement trait `AppendBar` for a vector of strings.
+impl AppendBar for Vec<String> {
+    fn append_bar(mut self) -> Self {
+        self.push(String::from("Bar"));
+        self
+    }
+}
 
 #[cfg(test)]
 mod tests {

exercises/15_traits/traits3.rs

@@ -8,10 +8,10 @@
 // Execute `rustlings hint traits3` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 pub trait Licensed {
-    fn licensing_info(&self) -> String;
+    fn licensing_info(&self) -> String {
+        String::from("Some information")
+    }
 }
 
 struct SomeSoftware {

exercises/15_traits/traits4.rs

@@ -7,8 +7,6 @@
 // Execute `rustlings hint traits4` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 pub trait Licensed {
     fn licensing_info(&self) -> String {
         "some information".to_string()
@@ -23,7 +21,7 @@ impl Licensed for SomeSoftware {}
 impl Licensed for OtherSoftware {}
 
 // YOU MAY ONLY CHANGE THE NEXT LINE
-fn compare_license_types(software: ??, software_two: ??) -> bool {
+fn compare_license_types(software: impl Licensed, software_two: impl Licensed) -> bool {
     software.licensing_info() == software_two.licensing_info()
 }
 

exercises/15_traits/traits5.rs

@@ -7,8 +7,6 @@
 // Execute `rustlings hint traits5` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 pub trait SomeTrait {
     fn some_function(&self) -> bool {
         true
@@ -30,7 +28,7 @@ impl SomeTrait for OtherStruct {}
 impl OtherTrait for OtherStruct {}
 
 // YOU MAY ONLY CHANGE THE NEXT LINE
-fn some_func(item: ??) -> bool {
+fn some_func(item: impl SomeTrait + OtherTrait) -> bool {
     item.some_function() && item.other_function()
 }
 

exercises/16_lifetimes/lifetimes1.rs

@@ -8,14 +8,8 @@
 // Execute `rustlings hint lifetimes1` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
-fn longest(x: &str, y: &str) -> &str {
-    if x.len() > y.len() {
-        x
-    } else {
-        y
-    }
+fn longest<'a>(x: &'a str, y: &'a str) -> &'a str {
+    if x.len() > y.len() { x } else { y }
 }
 
 fn main() {

exercises/16_lifetimes/lifetimes2.rs

@@ -6,14 +6,8 @@
 // Execute `rustlings hint lifetimes2` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
-fn longest<'a>(x: &'a str, y: &'a str) -> &'a str {
-    if x.len() > y.len() {
-        x
-    } else {
-        y
-    }
+fn longest<'a>(x: &'a str, y: &str) -> &'a str {
+    x
 }
 
 fn main() {

exercises/16_lifetimes/lifetimes3.rs

@@ -5,11 +5,9 @@
 // Execute `rustlings hint lifetimes3` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
-struct Book {
-    author: &str,
-    title: &str,
+struct Book<'a> {
+    author: &'a str,
+    title: &'a str,
 }
 
 fn main() {