Declaring the backpack

We can represent the player's backpack as a simple TMap<FString, int> item. To allow your player to gather items from the world, open the Avatar.h file and add the following TMap declaration:

class APickupItem; //  forward declare the APickupItem class,
                   // since it will be "mentioned" in a member  function decl below
UCLASS()
class GOLDENEGG_API AAvatar : public ACharacter
{
  GENERATED_UCLASS_BODY()

  // A map for the player's backpack
  TMap<FString, int> Backpack;

  // The icons for the items in the backpack, lookup by string
  TMap<FString, UTexture2D*> Icons;

  // A flag alerting us the UI is showing
  bool inventoryShowing;
  // member function for letting the avatar have an item
  void Pickup( APickupItem *item );
  // ... rest of Avatar.h same as before
};

Forward declaration

Before AAvatar class, notice that we have a class APickupItem forward declaration. Forward declarations are needed in a code...