Various minor/cosmetic improvements to code

src/liballoc/rc.rs

@@ -276,7 +276,7 @@ struct RcBox<T: ?Sized> {
 /// See the [module-level documentation](./index.html) for more details.
 ///
 /// The inherent methods of `Rc` are all associated functions, which means
-/// that you have to call them as e.g. [`Rc::get_mut(&mut value)`][get_mut] instead of
+/// that you have to call them as e.g., [`Rc::get_mut(&mut value)`][get_mut] instead of
 /// `value.get_mut()`. This avoids conflicts with methods of the inner
 /// type `T`.
 ///
@@ -1252,7 +1252,7 @@ impl<T: ?Sized> Weak<T> {
     }
 
     /// Return `None` when the pointer is dangling and there is no allocated `RcBox`,
-    /// i.e. this `Weak` was created by `Weak::new`
+    /// i.e., this `Weak` was created by `Weak::new`
     #[inline]
     fn inner(&self) -> Option<&RcBox<T>> {
         if is_dangling(self.ptr) {