Minor changes (to be squashed)

src/extension_traits/vec.rs

@@ -43,7 +43,7 @@ where
             slice::from_raw_parts_mut(
                 self.as_mut_ptr().cast::<MaybeUninit<T>>(),
                 capacity,
-            ).as_out::<[Self::Item]>()
+            ).as_out::<[T]>()
         }
     }
 
@@ -53,6 +53,7 @@ where
     /// it is not officially guaranteed that the allocation of a `Vec`
     /// (a `RawVec`) matches the allocation of a boxed slice, even if in their
     /// current implementations they do.
+    #[inline]
     fn into_backing_buffer (self: Vec<T>)
       -> Vec<MaybeUninit<T>> // ideally this would be a `Box<[]>`, but `Vec` does not guarantee it.
     {
@@ -83,6 +84,7 @@ where
     /// `&mut [MaybeUninit<T>]`.
     ///
     /// [backing buffer]: `VecAllocation::get_backing_buffer`
+    #[inline]
     fn split_at_extra_capacity (self: &'_ mut Vec<T>)
       -> (&'_ mut [T], &'_ mut [MaybeUninit<T>])
     {
@@ -158,6 +160,7 @@ where
     ///     b"Hello, World!",
     /// );
     /// ```
+    #[inline]
     fn reserve_uninit (self: &'_ mut Vec<T>, additional: usize)
       -> &'_ mut [MaybeUninit<T>]
     {