Native container component support
The Collections package provides native container types such as NativeList and NativeHashMap, plus unsafe containers such as UnsafeList. You can use these container types in components.
Both native and unsafe containers are value types rather than reference types. The key differences between Unsafe containers and Native containers are:
- You can only use the Jobs Debugger with native containers.
- Native containers copy a reference to its underlying data.
A NativeContainer is safer and consistently meets expectations than an UnsafeContainer.
Component limitations
If you put container types in a component, they have the following limitations:
| Functionality | Native containers | Unsafe containers |
|---|---|---|
| Compatible with Jobs Debugger | Yes | No |
| Can be used in job worker threads | Yes | Yes |
| Can be used on main thread | Yes | Yes |
| Usable with ComponentLookup on main thread | Yes | Yes |
| Usable with ComponentLookup in job worker threads | No | Yes |
Can contain other NativeContainers |
No | Yes This is technically supported but impacts performance. |
Can contain other UnsafeContainers |
Yes | Yes |
These restrictions don't apply to usage of native containers outside of components. For example, NativeContainers can nest other NativeContainers on the main thread (though it isn't possible to do this in job structs).