how do you create a UStruct?

Development Pipeline & Plugins Editor Scripting
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1

“How do you create a UStruct?” Surely that’s easy. Why am I even asking? BECAUSE IT REFUSES TO COMPILE.
USTRUCT requires GENERATED_USTRUCT_BODY(). GENERATED_USTRUCT_BODY() requires [whatever].generated.h. [whatever].generated.h apparently doesn’t get made until you compile a USTRUCT, WHICH DOESN’T HAPPEN WITHOUT GENERATED_USTRUCT_BODY().

I know it’s possible. I’ve managed to do it twice before. But for the life of me, I CAN’T REMEMBER HOW.

2

I think having the actual code might help? Maybe cleaning you’re project solution and recompiling could do the trick?

3

#pragma once

USTRUCT()
struct MYPROJECT_API FMyStruct
{
GENERATED_USTRUCT_BODY()
public:
FMyStruct();
~FMyStruct();
}

I have tried rebuilding. It didn’t work.

4

Is it you are missing a semi-colon at the end of the struct?

5

Also try taking away MYPROJECT_API. I’ve never seen it used anywhere in the engine and I don’t know but don’t think it should be used like that. Also you don’t need to specify public for structs the default accessibility is public for structs including USTRUCTS.

6

never seen MYPROJECT_API? It automatically adds that (or rather the equivalent, based on the project name) when you create a class from the editor.
The missing ; is because I missed it when selecting. Also, as note: the code above came from one of the two times I did manage it (minus the “FMyStruct.generated.h”). Change the name of the struct and you get what I’d be looking at when it was failing.

And yet, somehow I just managed it a third time. This is magical behavior. Code should not be magical.

7

Never seen the API macro used in UE4 code anywhere. You probably shouldn’t have it there. Also UCLASS’s require the generated.h not USTRUCTS, I suspect this is what’s causing you the issue.

8

Okay to be clear because I think i can be easily misunderstood, when I say never saw the API macro in UE4 code anywhere I mean, not used for structs. It is used for classes of course.