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Reinterpret_cast failing for FindRow<>()

Hi there,

I've just encountered an issue with FDataTableRowHandle.GetRow<>(). When trying to get a row that derives from another row the reinterpret_cast fails, but only if no property is set on the row struct that we cast from.

To be more specific here is a test setup:

 USTRUCT(BlueprintType)
 struct FSomeBaseRow : public FTableRowBase
 {
     GENERATED_BODY();
     
     UPROPERTY(EditDefaultsOnly, BlueprintReadWrite, Category = "Impact")
     UMaterial* defaultDecal;
     
 };
 
 USTRUCT(BlueprintType)
 struct FSomeDerivedRow : public FSomeBaseRow 
 {
     GENERATED_BODY();
     
     UPROPERTY(EditDefaultsOnly, BlueprintReadWrite, Category = "Impact")
     USoundCue* defaultSound;
 
 
     /** WORKAROUND! Adding this fake property fixes this issue */
         uint8 someFakeProperty = 0;
 };


Now when you have a FDataTableRowHandle that points to a FSomeDerivedRow it will only resolve the row when using GetRow<>() if: a) Some asset is assigned to defaultSound. If it's a nullptr the GetRow will fail. b) someFakeProperty is added and initialized

If not using one of the workarounds the GetRow will fail on FindRow<>()

 return reinterpret_cast<T*>(RowData);


Do you have any suggestions why this might be happening and how to fix it properly?

Regards, Jakub Przystolik

Product Version: UE 4.18
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asked Apr 16 '18 at 02:33 PM in C++ Programming

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Jakub.Przystoli1
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