112     inner: Impl<T>,
115 enum Impl<T> {  enum
124             inner: Impl::Empty(size),  in new()
130             Impl::Empty(size) => size / 2,  in free_oneway_space()
131             Impl::Array(array) => array.free_oneway_space(),  in free_oneway_space()
132             Impl::Tree(tree) => tree.free_oneway_space(),  in free_oneway_space()
138             Impl::Empty(_size) => 0,  in count_buffers()
139             Impl::Array(array) => array.count_buffers(),  in count_buffers()
140             Impl::Tree(tree) => tree.count_buffers(),  in count_buffers()
146             Impl::Empty(_size) => Ok(()),  in debug_print()
147             Impl::Array(array) => array.debug_print(m),  in debug_print()
148             Impl::Tree(tree) => tree.debug_print(m),  in debug_print()
155             Impl::Empty(size) => {  in reserve_new()
168                 self.inner = Impl::Array(empty_array);  in reserve_new()
171             Impl::Array(array) if array.is_full() => {  in reserve_new()
187                 self.inner = Impl::Tree(new_tree);  in reserve_new()
190             Impl::Array(array) => {  in reserve_new()
201             Impl::Tree(tree) => {  in reserve_new()
229             Impl::Empty(_size) => Err(EINVAL),  in reservation_abort()
230             Impl::Array(array) => array.reservation_abort(offset),  in reservation_abort()
231             Impl::Tree(tree) => {  in reservation_abort()
234                     self.inner = Impl::Empty(tree.total_size());  in reservation_abort()
247             Impl::Empty(_size) => Err(EINVAL),  in reservation_commit()
248             Impl::Array(array) => array.reservation_commit(offset, data),  in reservation_commit()
249             Impl::Tree(tree) => tree.reservation_commit(offset, data),  in reservation_commit()
258             Impl::Empty(_size) => Err(EINVAL),  in reserve_existing()
259             Impl::Array(array) => array.reserve_existing(offset),  in reserve_existing()
260             Impl::Tree(tree) => tree.reserve_existing(offset),  in reserve_existing()
269             Impl::Empty(_size) => {}  in take_for_each()
270             Impl::Array(array) => array.take_for_each(callback),  in take_for_each()
271             Impl::Tree(tree) => tree.take_for_each(callback),  in take_for_each()