# `allocator_api` The tracking issue for this feature is [#32838] [#32838]: https://github.com/rust-lang/rust/issues/32838 ------------------------ Sometimes you want the memory for one collection to use a different allocator than the memory for another collection. In this case, replacing the global allocator is not a workable option. Instead, you need to pass in an instance of an `AllocRef` to each collection for which you want a custom allocator. TBD