feat: added new exercises for generics

exercises/generics/generics2.rs

@@ -0,0 +1,28 @@
+// This powerful wrapper provides the ability to store a positive integer value.
+// Rewrite it using generics so that it supports wrapping ANY type.
+struct Wrapper<u32> {
+    value: u32
+}
+
+impl<u32> Wrapper<u32> {
+    pub fn new(value: u32) -> Self {
+        Wrapper { value }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn store_u32_in_wrapper() {
+        assert_eq!(Wrapper::new(42).value,  42);
+    }
+
+    #[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");
+    }
+}