20 /// let mut v = vec![0, 1, 2];
21 /// let iter: std::vec::Drain<_> = v.drain(..);
51     /// let mut vec = vec!['a', 'b', 'c'];
52     /// let mut drain = vec.drain(..);
54     /// let _ = drain.next().unwrap();
116                         let source_vec = self.0.vec.as_mut();  in drop()
118                         let start = source_vec.len();  in drop()
119                         let tail = self.0.tail_start;  in drop()
121                             let src = source_vec.as_ptr().add(tail);  in drop()
122                             let dst = source_vec.as_mut_ptr().add(start);  in drop()
131         let iter = mem::replace(&mut self.iter, (&mut []).iter());  in drop()
132         let drop_len = iter.len();  in drop()
134         let mut vec = self.vec;  in drop()
140                 let vec = vec.as_mut();  in drop()
141                 let old_len = vec.len();  in drop()
150         let _guard = DropGuard(self);  in drop()
160         let drop_ptr = iter.as_slice().as_ptr();  in drop()
167             let vec_ptr = vec.as_mut().as_mut_ptr();  in drop()
168             let drop_offset = drop_ptr.sub_ptr(vec_ptr);  in drop()
169             let to_drop = ptr::slice_from_raw_parts_mut(vec_ptr.add(drop_offset), drop_len);  in drop()