update again

exercises/generics/generics1.rs

@@ -1,10 +1,8 @@
 // This shopping list program isn't compiling!
 // Use your knowledge of generics to fix it.
 
-// I AM NOT DONE
-
 fn main() {
-    let mut shopping_list: Vec<?> = Vec::new();
+    let mut shopping_list: Vec<&str> = Vec::new();
     shopping_list.push("milk");
 }
 

exercises/generics/generics2.rs

@@ -1,13 +1,12 @@
 // This powerful wrapper provides the ability to store a positive integer value.
 // Rewrite it using generics so that it supports wrapping ANY type.
 
-// I AM NOT DONE
-struct Wrapper<u32> {
-    value: u32
+struct Wrapper<T> {
+    value: T
 }
 
-impl<u32> Wrapper<u32> {
-    pub fn new(value: u32) -> Self {
+impl<T> Wrapper<T> {
+    pub fn new(value: T) -> Self {
         Wrapper { value }
     }
 }
@@ -23,8 +22,6 @@ mod tests {
 
     #[test]
     fn store_str_in_wrapper() {
-        // TODO: Delete this assert and uncomment the one  below once you have  finished the exercise.
-        assert!(false);
-        // assert_eq!(Wrapper::new("Foo").value, "Foo");
+        assert_eq!(Wrapper::new("Foo").value, "Foo");
     }
 }

exercises/generics/generics3.rs

@@ -5,15 +5,15 @@
 
 // Make the necessary code changes to support alphabetical report cards, thereby making the second
 // test pass.
+use std::fmt::Display;
 
-// I AM NOT DONE
-pub struct ReportCard {
-    pub grade: f32,
+pub struct ReportCard<T> {
+    pub grade: T,
     pub student_name: String,
     pub student_age: u8,
 }
 
-impl ReportCard {
+impl<T:Display> ReportCard<T> {
     pub fn print(&self) -> String {
         format!("{} ({}) - achieved a grade of {}", &self.student_name, &self.student_age, &self.grade)
     }
@@ -37,7 +37,7 @@ mod tests {
     fn generate_alphabetic_report_card() {
         // TODO: Make sure to change the grade here after you finish the exercise.
         let report_card = ReportCard {
-            grade: 2.1, 
+            grade: "A+",
             student_name: "Gary Plotter".to_string(),
             student_age: 11,
         };

exercises/standard_library_types/iterators3.rs

@@ -7,8 +7,6 @@
 // Execute `rustlings hint iterators3` to get some hints!
 // Have fun :-)
 
-// I AM NOT DONE
-
 #[derive(Debug, PartialEq, Eq)]
 pub enum DivisionError {
     NotDivisible(NotDivisibleError),
@@ -70,12 +68,11 @@ mod tests {
     }
 
     // Iterator exercises using your `divide` function
-    /*
     #[test]
     fn result_with_list() {
         let numbers = vec![27, 297, 38502, 81];
         let division_results = numbers.into_iter().map(|n| divide(n, 27));
-        let x //... Fill in here!
+        let x = division_results.collect::<Result<Vec<_>, _>>();
         assert_eq!(format!("{:?}", x), "Ok([1, 11, 1426, 3])");
     }
 
@@ -83,8 +80,7 @@ mod tests {
     fn list_of_results() {
         let numbers = vec![27, 297, 38502, 81];
         let division_results = numbers.into_iter().map(|n| divide(n, 27));
-        let x //... Fill in here!
+        let x = division_results.collect::<Vec<_>>();
         assert_eq!(format!("{:?}", x), "[Ok(1), Ok(11), Ok(1426), Ok(3)]");
     }
-    */
 }

exercises/standard_library_types/iterators4.rs

@@ -1,7 +1,5 @@
 // iterators4.rs
 
-// I AM NOT DONE
-
 pub fn factorial(num: u64) -> u64 {
     // Complete this function to return the factorial of num
     // Do not use:
@@ -12,6 +10,7 @@ pub fn factorial(num: u64) -> u64 {
     // For an extra challenge, don't use:
     // - recursion
     // Execute `rustlings hint iterators4` for hints.
+    (1..num+1).fold(1, |m, x| m * x)
 }
 
 #[cfg(test)]

exercises/traits/traits1.rs

@@ -8,14 +8,15 @@
 // which appends "Bar" to any object
 // implementing this trait.
 
-// I AM NOT DONE
 trait AppendBar {
     fn append_bar(self) -> Self;
 }
 
 impl AppendBar for String {
-    //Add your code here
-
+    fn append_bar(mut self) -> Self {
+        self.push_str("Bar");
+        self
+    }
 }
 
 fn main() {

exercises/traits/traits2.rs

@@ -10,16 +10,16 @@
 // No boiler plate code this time,
 // you can do this!
 
-// I AM NOT DONE
-
 trait AppendBar {
     fn append_bar(self) -> Self;
 }
 
-//TODO: Add your code here
-
-
-
+impl AppendBar for Vec<String> {
+    fn append_bar(mut self) -> Self {
+        self.push(String::from("Bar"));
+        self
+    }
+}
 
 #[cfg(test)]
 mod tests {