The manual has a section on just this issue, although the manual can be a little confusing at times: http://caml.inria.fr/pub/docs/manual-ocaml/manual032.html#toc140 Sylvain Le Gall already mentioned the basics - registering the values with the garbage collector using CAMLparam (and then releasing them with CAMLreturn) prevents any problems. Also local values should be declared using CAMLlocal and global values should be registered using caml_global_register_root. On Tue, Apr 5, 2011 at 7:27 AM, Pedro Borges wrote: > Hi, everyone, > > If a compactification is triggered do the values get rewritten or do > they become invalid? > > > Best Regards, > > Pedro Borges > > -- > Caml-list mailing list. Subscription management and archives: > https://sympa-roc.inria.fr/wws/info/caml-list > Beginner's list: http://groups.yahoo.com/group/ocaml_beginners > Bug reports: http://caml.inria.fr/bin/caml-bugs > >