Add i32/u32 suffix for numeric literals in 04_traits/01_trait (#20)

Without an explicit suffix, the compiler is able to use the i32
implementation without the need for an u32 implementation.

book/src/04_traits/12_drop.md

@@ -1,6 +1,6 @@
 # The `Drop` trait
 
-When we introduced [destructors](../../02_ticket_v1/11_destructor/README.md),
+When we introduced [destructors](../03_ticket_v1/11_destructor),
 we mentioned that the `drop` function:
 
 1. reclaims the memory occupied by the type (i.e. `std::mem::size_of` bytes)

book/src/05_ticket_v2/01_enum.md

@@ -1,6 +1,6 @@
 # Enumerations
 
-Based on the validation logic you wrote [in a previous chapter](../../02_ticket_v1/02_validation), 
+Based on the validation logic you wrote [in a previous chapter](../03_ticket_v1/02_validation), 
 there are only a few valid statuses for a ticket: `To-Do`, `InProgress` and `Done`.  
 This is not obvious if we look at the `status` field in the `Ticket` struct or at the type of the `status` 
 parameter in the `new` method:

book/src/07_threads/04_scoped_threads.md

@@ -65,9 +65,9 @@ that `&v` can't be used from our spawned threads since its lifetime isn't
 
 That's not an issue with `std::thread::scope`—you can **safely borrow from the environment**.
 
-In our example, `v` is created before the spawning points.  
+In our example, `v` is created before the spawning points.
 It will only be dropped _after_ `scope` returns. At the same time,
-all threads spawned inside `scope` are guaranteed `v` is dropped,
+all threads spawned inside `scope` are guaranteed to finish _before_ `scope` returns,
 therefore there is no risk of having dangling references.  
 
-The compiler won't complain!
+The compiler won't complain!

exercises/04_traits/01_trait/src/lib.rs

@@ -9,15 +9,15 @@ mod tests {
 
     #[test]
     fn test_u32_is_even() {
-        assert!(42.is_even());
+        assert!(42u32.is_even());
-        assert!(!43.is_even());
+        assert!(!43u32.is_even());
     }
 
     #[test]
     fn test_i32_is_even() {
-        assert!(42.is_even());
+        assert!(42i32.is_even());
-        assert!(!43.is_even());
+        assert!(!43i32.is_even());
-        assert!(0.is_even());
+        assert!(0i32.is_even());
-        assert!(!(-1).is_even());
+        assert!(!(-1i32).is_even());
     }
 }

exercises/07_threads/10_patch/tests/check.rs

@@ -26,5 +26,6 @@ fn works() {
     client.update(patch).unwrap();
 
     let ticket = client.get(ticket_id).unwrap().unwrap();
-    assert_eq!(ticket_id, ticket.id);
+    assert_eq!(ticket.id, ticket_id);
+    assert_eq!(ticket.status, Status::InProgress);
 }