Cannot put FOnAttributeChangeData as delegate param or uproperty, even though it works fine in methods

[Chocfudges]

I want to create a multi-cast delegate that has FOnAttributeChangeData as the single param but the log keeps saying "Error: Unable to find ‘class’, ‘delegate’, ‘enum’, or ‘struct’ with name ‘FOnAttributeChangeData’ ", even though the method that also uses the struct as a parameter compiles just fine.

This will work fine

But using it in the delegate will cause "…\Public\GASCharacter.h(12) : Unable to find ‘class’, ‘delegate’, ‘enum’, or ‘struct’ with name ‘FOnAttributeChangeData’ "

Using it in uproperty will also cause "…\Public\GASCharacter.h(24) : Error: Unable to find ‘class’, ‘delegate’, ‘enum’, or ‘struct’ with name ‘FOnAttributeChangeData’ "

Why does the struct FOnAttributeChangeData didn’t work in the delegate or the uproperty even though just one line above it, it worked just fine?

[bsteeletx]

Did you ever get a solution to this? I’m running into a similar (if not exact) problem.

[UnrealEverything]

All parameter types of dynamic delegates must be supported by reflection. FOnAttributeChangeData doesn’t have the required macros so it isn’t. Same if you want to use it as a UPROPERTY.

What you can do is wrap the FOnAttributeChangeData in another struct that you expose to reflection. However this may be dangerous since it contains a raw pointer const FGameplayEffectModCallbackData* GEModData; that could easily become dangling. And you’d have to deal with garbage collection of the contained UObject’s.