<html><head><style type="text/css">.style1 {font-family: "Times New Roman";}</style></head><body>Hi Sverker,<BR>
<BR>
Many thanks for sharing your thoughts; the outcome is as I expected but it is<BR>
useful to have checked. I will refrain from abusing the opacity.<BR>
<BR>
Regards,<BR>
<BR>
Robert<BR>
<BR>
<BR>
> On 27 Sep 2021, at 10:57, Sverker Eriksson <sverker.eriksson@ericsson.com> wrote:<BR>
><BR>
> No there is no ERL_NIF_TERM_UNINITIALISED in the erl_nif API.<BR>
><BR>
> There is one erts internal called THE_NON_VALUE, which is what is returned by enif_raise_exception and makes enif_is_exception return true.<BR>
><BR>
> So it would be possible to introduce, but I'm not sure how to best make it fit in with the existing "exception" value.<BR>
><BR>
> If you just want to do something quick and dirty use the value zero. But don't complain if that stops working at some time.<BR>
><BR>
> /Sverker, Erlang/OTP<BR>
> From: erlang-questions <erlang-questions-bounces@erlang.org> on behalf of Robert Harris <robert.harris@alertlogic.com><BR>
> Sent: Wednesday, September 22, 2021 12:50 PM<BR>
> To: <a href="mailto:erlang-questions@erlang.org">erlang-questions@erlang.org</a> Questions <erlang-questions@erlang.org><BR>
> Subject: Test for valid ERL_NIF_TERM<BR>
><BR>
> Are any values of ERL_NIF_TERM reserved to mean "invalid"? I.e. is<BR>
> there a blessed equivalent of<BR>
><BR>
> ERL_NIF_TERM optional = ERL_NIF_TERM_UNINITIALISED;<BR>
> .<BR>
> .<BR>
> .<BR>
> if (optional != ERL_NIF_TERM_UNINITIALISED)<BR>
> do_something(optional)<BR>
><BR>
> ?<BR>
><BR>
> Robert<BR>
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