ResetAndDestroy is an inline method, you can find it in e32base.inl of any SDK:
EDIT: note that your code is actually bogus: Remove shifts the entire array, which results in emptying half of the array only at the end (objects at even indices of the original array are removed). Also, re-organizing the array after every step requires some effort too.
template <class T>
<comment part removed>
for (TInt i=0;i<this->Count();++i)
Now as I see, Count is not a method call either, so I guess the snippet is probably more of a pseudo-code than a real one.