Hi,
The short version:
The current rule of thumb is that you don’t need to use TObjectPtr outside of UPROPERTY members.
The longer version:
We have four current use cases for TObjectPtr:
- Access tracking during cook for computing dependencies for incremental cooks [experimental]
- Allowing for incremental garbage collection [experimental]
- Facilitating remote object references on other machines [pre-experimental]
- Allowing for lazy load of imported references [not currently used]
Each of these usage scenarios has slightly different needs, and these usage scenarios change over time. But we need consistent guidance for TObjectPtr usage that doesn’t change with the usage scenarios, and the simple rule of thumb above is adequate. There are a few situations where you might have a frequently running inner loop with some condition that receives TObjectPtr and converts them to raw pointers, and that will function correctly but cause every TObjectPtr to count as being accessed and trigger the access tracking logic even if the condition doesn’t pass and we don’t actually access it. That’s an example of a situation where it can be desirable to not convert from TObjectPtr to raw pointer. But these are abnormal and not something that should be part of general guidance.
A more complete rule would be: Use TObjectPtrs when you have object references that will be expected to span a garbage collect.