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How to create a globally-available enum?

Development Discussion C++ Gameplay Programming
#1

Hey,

I want to create a enum that contains the different types of weapons I will have (handgun, rifle, melee, etc). But if I define this enum in the c++ weapon class, my pawn’s animation blueprint can’t access it. (I need my animblueprint to access it, because I need to have the pawn doing a different animation depending on the current weapon type.)

So where can I define an enumeration so that everything, anywhere, can see it? I’m using C++, so I can’t declare one in the content browser. I also tried declaring it in MyProject.h, but that gave me errors. (?)

Thanks in advance :slight_smile:

#2

Hi Greg,

If you mark your enum declaration with UENUM(BlueprintType), then the enum should be usable in any Blueprints, including Anim Blueprints.

Cheers,
Michael Noland

#3

Copy and Paste the code that you put in the MyProject.h, and the errors you got.
Are you using UENUMTYPE()?
Here’s a tutorial (scroll down to the C++ code): What is proper way to make Enum for BP and C++ both - UE4 AnswerHub

#4

@Micheal Noland, yep, it shows up in blueprints now! Thanks :slight_smile:

@jwatte, here’s my GB.h code (GB is the name of my project):

[HR][/HR]
#ifndef GB_H
#define GB_H

#include “Engine.h”

#define COLLISION_PROJECTILE ECC_GameTraceChannel1

#endif

#include “GB.generated.h”

UENUM(BlueprintType)
enum EItemAnimType
{ None UMETA(DisplayName = “None”),
Rifle UMETA(DisplayName = “Rifle”),
Handgun UMETA(DisplayName = “Handgun”),
Melee UMETA(DisplayName = “Melee”)
};
[HR][/HR]
And I get this huge wall of errors:

c:\users\greg\documents\unreal projects\gb\intermediate\build\win64\inc\gb…/…/…/…/…/Source/GB/GB.h(26): error C2011: ‘EItemAnimType’ : ‘enum’ type redefinition
1> c:\users\greg\documents\unreal projects\gb\intermediate\build\win64\inc\gb…/…/…/…/…/Source/GB/GB.h(26) : see declaration of ‘EItemAnimType’
1>c:\users\greg\documents\unreal projects\gb\source\gb\GB.h(26): error C2011: ‘EItemAnimType’ : ‘enum’ type redefinition
1> c:\users\greg\documents\unreal projects\gb\source\gb\GB.h(26) : see declaration of ‘EItemAnimType’
1>c:\users\greg\documents\unreal projects\gb\source\gb\GB.h(26): error C2011: ‘EItemAnimType’ : ‘enum’ type redefinitionc:\users\greg\documents\unreal projects\gb\source\gb\GB.h(26) : error C2011: ‘EItemAnimType’ : ‘enum’ type redefinition
1>
1> c:\users\greg\documents\unreal projects\gb\source\gb\GB.h(26) : see declaration of ‘EItemAnimType’ c:\users\greg\documents\unreal projects\gb\source\gb\GB.h(26) : see declaration of ‘EItemAnimType’
1>
1> GBUIWidget.cpp
1>c:\users\greg\documents\unreal projects\gb\source\gb\GB.h(26): error C2011: ‘EItemAnimType’ : ‘enum’ type redefinition
1> c:\users\greg\documents\unreal projects\gb\source\gb\GB.h(26) : see declaration of ‘EItemAnimType’
1> GBPants.cpp
1>c:\users\greg\documents\unreal projects\gb\source\gb\GB.h(26): error C2011: ‘EItemAnimType’ : ‘enum’ type redefinition
1> c:\users\greg\documents\unreal projects\gb\source\gb\GB.h(26) : see declaration of ‘EItemAnimType’
1> GBShirt.cpp
1> GBClothing.cpp
1>c:\users\greg\documents\unreal projects\gb\source\gb\GB.h(26): error C2011: ‘EItemAnimType’ : ‘enum’ type redefinition
1> c:\users\greg\documents\unreal projects\gb\source\gb\GB.h(26) : see declaration of ‘EItemAnimType’
1>c:\users\greg\documents\unreal projects\gb\source\gb\GB.h(26): error C2011: ‘EItemAnimType’ : ‘enum’ type redefinition
1> c:\users\greg\documents\unreal projects\gb\source\gb\GB.h(26) : see declaration of ‘EItemAnimType’
1> GBBackpack.cpp
1>c:\users\greg\documents\unreal projects\gb\source\gb\GB.h(26): error C2011: ‘EItemAnimType’ : ‘enum’ type redefinition
1> c:\users\greg\documents\unreal projects\gb\source\gb\GB.h(26) : see declaration of ‘EItemAnimType’
1> GBWeapon.cpp
1> GBInventoryManager.cpp
1> GBInventoryItem.cpp
1>c:\users\greg\documents\unreal projects\gb\source\gb\GB.h(26): error C2011: ‘EItemAnimType’ : ‘enum’ type redefinitionc:\users\greg\documents\unreal projects\gb\source\gb\GB.h(26) : error C2011: ‘EItemAnimType’ : ‘enum’ type redefinition
1>
1> c:\users\greg\documents\unreal projects\gb\source\gb\GB.h(26) : see declaration of ‘EItemAnimType’ c:\users\greg\documents\unreal projects\gb\source\gb\GB.h(26) : see declaration of ‘EItemAnimType’
1>
1>c:\users\greg\documents\unreal projects\gb\source\gb\GB.h(26): error C2011: ‘EItemAnimType’ : ‘enum’ type redefinition
1> c:\users\greg\documents\unreal projects\gb\source\gb\GB.h(26) : see declaration of ‘EItemAnimType’
1> GBProjectile.cpp
1>c:\users\greg\documents\unreal projects\gb\source\gb\GB.h(26): error C2011: ‘EItemAnimType’ : ‘enum’ type redefinition
1> c:\users\greg\documents\unreal projects\gb\source\gb\GB.h(26) : see declaration of ‘EItemAnimType’
1> GB.cpp
1>c:\users\greg\documents\unreal projects\gb\source\gb\GB.h(26): error C2011: ‘EItemAnimType’ : ‘enum’ type redefinition
1> c:\users\greg\documents\unreal projects\gb\source\gb\GB.h(26) : see declaration of ‘EItemAnimType’

Actually, it’s the same error over and over again. But how do I fix it? :frowning:

#5

They are beeing redefined so if you dont have the same code in two places.
Then your header is beeing included “twice”.

I think your issue may be the inclusion guards.
I think i read somewhere that you need to use the visual studio one.


#pragma once

And it also probeboly be a good idea to create a namespace for them.

#6

Thanks! Fixed it! I noticed that #pragma once is included in most of the source files by default, but not GB.h. Wonder why.

One more thing: is it bad to #include “GB.h” in both the .h and .cpp files for other classes? By default it’s only included in the .cpp, but I want to declare some of my custom enums in the .h.

#7

Heya,

Just like to pop in here o share the way I handle enums and structs. This is mostly based off of a tutorial from the wiki by Rama, so credits to him. Here’s my code:


#pragma once
#include "Archrune.h"
#include "Constants.generated.h"

UCLASS()
class UConstants : public UBlueprintFunctionLibrary
{
	GENERATED_UCLASS_BODY()
};


#pragma region ENUMS

UENUM(BlueprintType)
namespace ELevelState
{
	enum Type
	{
		Locked,
		Open,
		Complete
	};
}


UENUM(BlueprintType)
namespace EPlayerCameraAxisState
{
	enum Type
	{
		Free,
		AttachedRelative,
		AttachedWorld
	};
}

#pragma endregion ENUMS



#pragma region STRUCTS

USTRUCT(BlueprintType)
struct FLevelStruct : public FTableRowBase
{
	GENERATED_USTRUCT_BODY()


	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Level Properties")
	uint8 Level_Index;

	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Level Properties")
	FText Level_Name;

	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Level Properties")
	TEnumAsByte<ELevelState::Type> Level_State;
};

#pragma endregion STRUCTS

This allows me to have enums and structs in a single organized file, but also have a bunch of INLINE functions in the header allowing for a sort of GameUtility script. It’s really handy for keeping stuff organized.

#8

@DamirH: This is very usefull thanks for the share it gave me some ideas as well :slight_smile:

#9

#pragma once is poor form.

You actually had almost the right solution already in the original file, except you had the “#endif” for the GB_H in the wrong place – it should be at the end.


#ifndef __GB_H__
#define __GB_H__

#include "Engine.h"

#define COLLISION_PROJECTILE ECC_GameTraceChannel1

// #endif  // this was wrong

#include "GB.generated.h"


UENUM(BlueprintType)
enum EItemAnimType
{
None UMETA(DisplayName = "None"),
Rifle UMETA(DisplayName = "Rifle"),
Handgun UMETA(DisplayName = "Handgun"),
Melee UMETA(DisplayName = "Melee")
};

#endif  // this is what it should have been
#10

Not really… It’s supported by pretty much every noteworthy compiler out there today.

#11

@jwatte, that actually didn’t work for me for some reason, I needed the pragma once for it to work. No matter, “pragma once” compiles, that’s good enough for me :slight_smile:

(Sorry for late reply, internet’s been down.)

#12

The resson for this is that (and am 99.99% sure about this).
That some where in the documentation it says NOT to use inclusion guards like #ifndef FILE_H …
But use the #pragma once i reserve the right to be wrong here but am prety sure about it.

Am sure a UE 4 Dev drops by soon enofe and confirm this or not :wink: