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[GC] Object variables collected prematurely

Hi Everyone,

Problem - Objects created in actor constructor and stored in TMap are getting variables collected (set to random) after start of the game.

Details In ATestActor I create 500 UTestObjects. Each of them has variable id=0 defined in UTestObject header. In "Begin Play" I go through whole map printing out ids of each UTestObject and getting values like -842150451 etc.

If I do the printing in constructor, it works and outputs 0 for each object.

Garbage collector should not collect those since I have pointers to them stored.

I am sure I am missing something trivial,

Thanks for any help,

Crispy

.

Code

ATestActor class

 ATestActor::ATestActor()
 {    
     for (int i = 0; i < 500; i++)
     {
         FName RendererName = FName(*("ObjectName" + FString::FromInt(i)));
         map.Add(i, NewObject<UTestObject>(this, RendererName));
     }
 }
 
 
 void ATestActor::BeginPlay()
 {
     Super::BeginPlay();
 
     for (int i = 0; i < 500; i++)
     {
         int id = (*(map.Find(i)))->id;
         UE_LOG(LogTemp, Warning, TEXT("id %d"), id);
     }
 }`

//Simple TestObject header

 UCLASS()
 class BUILDTEST_API UTestObject : public UObject
 {
     GENERATED_BODY()
 
 public:
     int id = 0;
 };



Product Version: UE 4.13
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asked Dec 04 '16 at 05:29 PM in C++ Programming

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Crispy_Penguin
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Answer - TMap and other containers has to be declared with UPROPERTY() in the header file. More info here https://wiki.unrealengine.com/Garbage_Collection_%26_Dynamic_Memory_Allocation

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answered Dec 04 '16 at 06:07 PM

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Crispy_Penguin
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