void MyClass::create_subscription()
{
clear_subscription();

TUaSubscription* s = new TUaSubscription();
_di_IUaSubscription sub = s->operator _di_IUaSubscription();

// does m_OpcUaClient take ownership of s?
m_OpcUaClient->AddSubscription( sub )

// remember subscription for later use
m_ActiveSubscription = s;
}

TUaSubscription* MyClass::get_active_subscription()
{
return m_ActiveSubscription;
}

void MyClass::clear_subscription()
{
TUaSubscription* s = get_active_subscription();
if( s )
{
_di_IUaSubscription sub = s->operator _di_IUaSubscription();
m_OpcUaClient->RemoveSubscription( sub )

// Do I have to delete the active subscription? Or can I just set it to nullptr?
delete m_ActiveSubscription; // ?
m_ActiveSubscription = nullptr;
}
}