UENUM enum class with uint8

anonymous_user_0b55f4d0 · October 2, 2018, 6:41pm

Hello, I have a question here about the enum class in UE4 , now is the I have more than 255 values to set in a enum class like :

ENUM(BlueprintType)
enum class ECityMapMeshTag : uint8
{
  RoadTwoLanes_LaneLeft               UMETA(DisplayName = "Road: Two Lanes - Lane Left"),
  RoadTwoLanes_LaneRight              UMETA(DisplayName = "Road: Two Lanes - Lane Right"),
  RoadTwoLanes_SidewalkLeft           UMETA(DisplayName = "Road: Two Lanes - Sidewalk Left"),
  RoadTwoLanes_SidewalkRight          UMETA(DisplayName = "Road: Two Lanes - Sidewalk Right"),
  RoadTwoLanes_LaneMarkingSolid       UMETA(DisplayName = "Road: Two Lanes - Lane Marking Solid"),
  RoadTwoLanes_LaneMarkingBroken      UMETA(DisplayName = "Road: Two Lanes - Lane Marking Broken"),
...
...
...
\\\more than 255 Tags.
  NUMBER_OF_TAGS         UMETA(Hidden),
  INVALID                UMETA(Hidden)
};

But type enums support uint8 only, can I use uint32 instead of uint8? if not , how can I do to make the maximal value more than 255??

Ali_Akbar · October 3, 2018, 3:20am

It works without blueprint support, but if you want to expose this to blueprints, you’ll have to stick with uint8

UENUM()
enum class ECityMapMeshTag : uint16
{
	RoadTwoLanes_LaneLeft               UMETA(DisplayName = "Road: Two Lanes - Lane Left")
};

The above code compiles just fine if I remove BlueprintType from UENUM

anonymous_user_0b55f4d0 · October 5, 2018, 4:55pm

Thanks, that helps.

TheDreamCatcher · October 6, 2018, 5:19am

the other way around would be to rethink your enums. You might want to shrunk down such a massive enum into smaller pieces that would be more relevant. For instance separate things in two at first with sidewalks in an enum and main road in an other, and so on.

MRSagor949 · January 25, 2021, 8:48pm

Hey, When I try to create enum with class . I got a lots of erros in my visual studio . Now how can i fix it.
#pragma once

#include “CoreMinimal.h”
#include “MRSEnumLibrary.generated.h”

UENUM(BlueprintType)
enum class EGait : uint8
{
Walking,
Running,
Sprinting,
};

I don’t know what is the prlm.

MRSagor949 · January 26, 2021, 9:40pm

I could not create any types of enum in my header file with a none c++ class.