extending records with Obj.magic

[Nicolas Ojeda Bar <nojb@math.harvard.edu>]

Hello,

I need extensible records, and the code below seems to
work. Are there any pitfall that I should be aware of?
Could this mess up the GC?

# type t0 = { a : int };
# type t1 = { a2 : int; b : int };
# value x1 = { a2 = 3; b = 5 };
# value x0 : t0 = Obj.magic x1;
value x0 = { a = 3 }
# value x0' : t1 = Obj.magic x0;
value x0' = { a2 = 3; b = 5 }

(supposedly t1 is an extension of t0). The types are
being generated by a program, so I am not worried about
actually having to _write_ this myself.

Thanks!
N