I am a bit confused about how to use object handle. Here is the code example I was trying to compile with the add-on array:

class Obj {
  int x;
};

void main() {
  array<Obj@> a(3);
  Obj o;
  o.x = 10;
  a[0] = @o;
}

The @ symbol goes on the left hand expression to signal a handle assignment. The right hand expression can also be pre-fixed with @, but that is optional.

 @a[0] = o;

Without the @ symbol the assignment will be done by value, i.e. calling the Obj's opAssign operator.

I see, thank you very much!