can't understand this piece of code

[knowledge_Seeker1]

Dear All,

I am seeking the help of people who know c++ .

Could anybody explain to me what is going on here ?

( i am tryin to learn ns3 and these codes are taken from ns3 tutorial chap7 )

class MyObject : public Object
{
public:
static TypeId GetTypeId (void)
{
static TypeId tid = TypeId ("MyObject")
.SetParent (Object::GetTypeId ())
.AddConstructor<MyObject> ()
.AddTraceSource ("MyInteger",
"An integer value to trace.",
MakeTraceSourceAccessor (&MyObject::m_myInt))
;
return tid;
}
MyObject () {}
TracedValue<int32_t> m_myInt;
};


void
IntTrace (int32_t oldValue, int32_t newValue)
{
std::cout << "Traced " << oldValue << " to " << newValue << std::endl;
}


int
main (int argc, char *argv[])
{
Ptr<MyObject> myObject = CreateObject<MyObject> ();
myObject->TraceConnectWithoutContext ("MyInteger", MakeCallback(&IntTrace));
myObject->m_myInt = 1234;
}

your help is HIGHLY appreciated