Performance of immediate objects

["Chris King" <colanderman@gmail.com>]

Is there a substantial difference to the way in which

class foo (i:int) = object
 val v = i
 method bar = v
end

let mk_foo i = new foo i

and

let mk_foo (i:int) = object
 val v = i
 method bar = v
end

are compiled?  I've run a couple tests with the above and immediate
objects seem to be about 15% slower than classes.  Is this because a
new method table is created for the immediate object every time or is
that the case for classes also?

- Chris King