- [x] Thread local allocator.
- [x] Lock reuse
- [ ] Freeze/unfreeze -- memcompression
- [ ] Proper error messages in unwraps.
- [ ] Checkpoints
- [ ] Fast `calloc`
- [ ] Microcaches.
- [ ] Skip blocks.
- [ ] Flattening
- [ ] Deallocation cache.
- [ ] Static assumptions.
- [ ] Thread local storage.
- [x] Check `checks` handling of null overlaps.
- [x] `insert` (and probably `free_inplace`) is possibly due to null overlaps.