+--------+----------------------------------+
| bitmap | 00000000000000100000000000000010 |
+--------+----------------------------------+
|        | +-+-+                            |
| array  | | | |                            |
|        | +++++                            |
+--------+--+-+-----------------------------+
            | |
            | +------------+
            |              |
            v              v
       /----------\  /----------\
       | baz → 66 |  | foo → 42 |
       \----------/  \----------/