message: comments and another test
diff: @@ -5,15 +5,15 @@ fn test_align_offset() {
  assert_eq!(raw.align_offset(2), 0);
  assert_eq!(raw.align_offset(4), 0);
  - assert_eq!(raw.align_offset(8), usize::max_value());
  + assert_eq!(raw.align_offset(8), usize::max_value()); // requested alignment higher than allocation alignment
  assert_eq!(raw.wrapping_offset(1).align_offset(2), 1);
  assert_eq!(raw.wrapping_offset(1).align_offset(4), 3);
  - assert_eq!(raw.wrapping_offset(1).align_offset(8), usize::max_value());
  + assert_eq!(raw.wrapping_offset(1).align_offset(8), usize::max_value()); // requested alignment higher than allocation alignment
  assert_eq!(raw.wrapping_offset(2).align_offset(2), 0);
  assert_eq!(raw.wrapping_offset(2).align_offset(4), 2);
  - assert_eq!(raw.wrapping_offset(2).align_offset(8), usize::max_value());
  + assert_eq!(raw.wrapping_offset(2).align_offset(8), usize::max_value()); // requested alignment higher than allocation alignment
  }
  fn test_align_to() {
  @@ -54,6 +54,13 @@ fn test_align_to() {
  assert_eq!(r.len(), 3);
  assert_eq!(raw.wrapping_offset(4), m.as_ptr() as *const u8);
  }
  +
  + {
  + let (l, m, r) = unsafe { s.align_to::<u64>() }; // requested alignment higher than allocation alignment
  + assert_eq!(l.len(), 4*N);
  + assert_eq!(r.len(), 0);
  + assert_eq!(m.len(), 0);
  + }
  }
  fn test_from_utf8() {
  