To inline or not to inline

Question

I've been writing a few classes lately; and I was wondering whether it's bad practice, bad for performance, breaks encapsulation or whether there's anything else inherently bad with actually defining some of the smaller member functions inside a header (I did try Google!). Here's an example I have of a header I've written with a lot of this:

class Scheduler {
public:
    typedef std::list<BSubsystem*> SubsystemList;

    // Make sure the pointer to entityManager is zero on init
    // so that we can check if one has been attached in Tick()
    Scheduler() : entityManager(0) { }

    // Attaches a manager to the scheduler - used by Tick()
    void AttachEntityManager( EntityManager &em )
        { entityManager = &em; }

    // Detaches the entityManager from a scheduler.
    void DetachEntityManager()
        { entityManager = 0; }

    // Adds a subsystem to the scheduler; executed on Tick()
    void AddSubsystem( BSubsystem* s )
        { subsystemList.push_back(s); }

    // Removes the subsystem of a type given
    void RemoveSubsystem( const SubsystemTypeID& );

    // Executes all subsystems
    void Tick();

    // Destroys subsystems that are in subsystemList
    virtual ~Scheduler();
private:
    // Holds a list of all subsystems
    SubsystemList subsystemList;

    // Holds the entity manager (if attached)
    EntityManager *entityManager;
};

So, is there anything that's really wrong with inlining functions like this, or is it acceptable?

(Also, I'm not sure if this'd be more suited towards the 'code review' site)

Answer 1

In fact you can write all your functions in the header file, if the function is too large the compiler will automatically not inline the function. Just write the function body where you think it fits best, let the compiler decide. The inline keyword is ignored often as well, if you really insist on inlining the function use __forceinline or something similar (I think that is MS specific).