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();
78     /// let mut vec = vec!['a', 'b', 'c'];
79     /// let mut drain = vec.drain(..);
105         let mut this = ManuallyDrop::new(self);  in keep_rest()
108             let source_vec = this.vec.as_mut();  in keep_rest()
110             let start = source_vec.len();  in keep_rest()
111             let tail = this.tail_start;  in keep_rest()
113             let unyielded_len = this.iter.len();  in keep_rest()
114             let unyielded_ptr = this.iter.as_slice().as_ptr();  in keep_rest()
118                 let start_ptr = source_vec.as_mut_ptr().add(start);  in keep_rest()
122                     let src = unyielded_ptr;  in keep_rest()
123                     let dst = start_ptr;  in keep_rest()
130                     let src = source_vec.as_ptr().add(tail);  in keep_rest()
131                     let dst = start_ptr.add(unyielded_len);  in keep_rest()
185                         let source_vec = self.0.vec.as_mut();  in drop()
187                         let start = source_vec.len();  in drop()
188                         let tail = self.0.tail_start;  in drop()
190                             let src = source_vec.as_ptr().add(tail);  in drop()
191                             let dst = source_vec.as_mut_ptr().add(start);  in drop()
200         let iter = mem::take(&mut self.iter);  in drop()
201         let drop_len = iter.len();  in drop()
203         let mut vec = self.vec;  in drop()
209                 let vec = vec.as_mut();  in drop()
210                 let old_len = vec.len();  in drop()
219         let _guard = DropGuard(self);  in drop()
229         let drop_ptr = iter.as_slice().as_ptr();  in drop()
236             let vec_ptr = vec.as_mut().as_mut_ptr();  in drop()
237             let drop_offset = drop_ptr.sub_ptr(vec_ptr);  in drop()
238             let to_drop = ptr::slice_from_raw_parts_mut(vec_ptr.add(drop_offset), drop_len);  in drop()