USubsystem

Subsystems are auto instanced classes that share the lifetime of certain engine constructs

Currently supported Subsystem lifetimes are: Engine -> inherit UEngineSubsystem Editor -> inherit UEditorSubsystem GameInstance -> inherit UGameInstanceSubsystem World -> inherit UWorldSubsystem LocalPlayer -> inherit ULocalPlayerSubsystem

Normal Example: class UMySystem : public UGameInstanceSubsystem Which can be accessed by: UGameInstance* GameInstance = ...; UMySystem* MySystem = GameInstance->GetSubsystem<UMySystem>();

or the following if you need protection from a null GameInstance UGameInstance* GameInstance = ...; UMyGameSubsystem* MySubsystem = UGameInstance::GetSubsystem<MyGameSubsystem>(GameInstance);

You can get also define interfaces that can have multiple implementations. Interface Example : MySystemInterface With 2 concrete derivative classes: MyA : public MySystemInterface MyB : public MySystemInterface

Which can be accessed by: UGameInstance* GameInstance = ...; const TArray<UMyGameSubsystem*>& MySubsystems = GameInstance->GetSubsystemArray<MyGameSubsystem>();