Resolving circulatory dependencies

Development Programming & Scripting C++
1

I have this particular issue where I want to reference my anim instance class in my character class and my character class in my anim instance class. This results in a circulatory dependency where both classes rely on the other and spit out the “missing type specifier” errors. The files:

MyAnimInstance.h



#include "MyCharacter.h" // <- This is one half of the problem

class CPPCHARACTERMOVEMENT_API UMyAnimInstance: public UAnimInstance
{
    GENERATED_BODY()

protected:
    UFUNCTION(BlueprintCallable, Category = "InitialiseAnimation")
    void InitAnimation();

private:
    UPROPERTY()
    const AMyCharacter* MyCharacterReference;
}

MyAnimInstance.cpp



#include "MyAnimInstance.h"

void UMyAnimInstance::InitAnimation()
{
    // During init animation, it is asserted that the controlled pawn indeed is AALSCharacter
    MyCharacterReference = Cast<AMyCharacter>(TryGetPawnOwner());
    check(MyCharacterReference)
}

MyCharacter.h



#include "MyAnimInstance.h" // <- This is the other half of the problem

class CPPCHARACTERMOVEMENT_API AMyCharacter: public ACharacter
{
    GENERATED_BODY()

protected:
    virtual void PostInitProperties() override;

    UPROPERTY()
    const UMyAnimInstance* MyAnimInstanceReference;
}

MyCharacter.cpp



#include "MyCharacter.h"

void AMyCharacter::PostInitProperties()
{
    MyAnimInstanceReference = Cast<UMyAnimInstance>(GetMesh()->GetAnimInstance());
    check(MyAnimInstanceReference)
}

Is there are graceful and/or inbuilt way of handling circular dependencies in Unreal? What is the best or correct way of resolving the issue where two classes rely on each other?

2

Forward declare character class into anim Instance class, or use a character base class.

3

// AA.h
#include “AA.generated.h”
class BB; <==

//AA.cpp
#include “BB.h” <==
#include “AA.h”

//BB.h
#include “AA.h” <==
#include “BB.generated.h”