"Sylvain Le Gall" <sylvain@le-gall.net>:
>
> This is not about optimized compiler in this case but about data
> representation. Even if you use an optimized compiler (which is not
> really the case with ocamlopt), you won't change datastructure
> representation to optimize.

What do you mean? There is no reason in general why a compiler cannot
optimize data representations, and some do in cases like this.

/Andreas