How to use FAutoConsoleVariableRef with class member variable

Development Programming & Scripting
1

I am trying to use FAutoConsoleVariableRef with a existing class member variable to prevent the GetValueOnGameThread() call in every tick of my application. I want to use my class variable as a cache for the value which should simply be updated if the value changes from the console. However, I get a compiler error when trying to use FAutoConsoleVariableRef. Stripped down example PlayerCharacter.h/.cpp:

class APlayerCharacter : public ACharacter
{
private:
    FAutoConsoleVariableRef CVar_MyVar;

public:
    UPROPERTY(VisibleAnywhere, BlueprintReadOnly)
    float MyVar = 1.0f;

    // ...
};

APlayerCharacter::APlayerCharacter(/* ... */) :
        Super(/* ... */),
        CVar_MyVar(TEXT("MyVar"),
                MyVar,
                TEXT("Some Description"),
                ECVF_Scalibility | ECVF_RenderThreadSafe)
{
    // ...
}

So I want to initialize the variable with the constructor like one would usually do. But for some reason, UE generates a file called PlayerCharacter.gen.cpp which generates another constructor which overwrites my own one without initializing the CVar_MyVar which ultimately results in this error:

PlayerCharacter.gen.cpp:110:32: error: 
      constructor for 'APlayerCharacter' must explicitly initialize the member 'CVar_MyVar' which does not have a default constructor
        DEFINE_VTABLE_PTR_HELPER_CTOR(APlayerCharacter);
                                      ^
PlayerCharacter.h:19:26: note: member is declared here
        FAutoConsoleVariableRef CVar_MyVar;
                                ^
/Engine/Source/Runtime/Core/Public/HAL/IConsoleManager.h:824:16: note: 
      'FAutoConsoleVariableRef' declared here
class CORE_API FAutoConsoleVariableRef : private FAutoConsoleObject
               ^
1 error generated.

Any ideas on how to fix this are much appreciated.

2

Six years too late, but for everybody else interested, you need to initialize it in .h file (declaration of the class), so in your case

{
private:
    FAutoConsoleVariableRef CVar_MyVar = FAutoConsoleVariableRef(TEXT("MyVar"), MyVar, TEXT("Some Description"), ECVF_Scalibility | ECVF_RenderThreadSafe);
1 Like