Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uflorida!haven!adm!smoke!gwyn
From: gwyn@smoke.BRL.MIL (Doug Gwyn)
Newsgroups: comp.lang.c
Subject: Re: enum implementation
Keywords: enum, types, char/int
Message-ID: <10612@smoke.BRL.MIL>
Date: 26 Jul 89 15:27:57 GMT
References: <396@opusys.UUCP>
Reply-To: gwyn@brl.arpa (Doug Gwyn)
Organization: Ballistic Research Lab (BRL), APG, MD.
Lines: 22

In article <396@opusys.UUCP> rlkd@opusys.UUCP (R.L.K.Dattatri) writes:
>Recently, while using two different compilers I ran into a problem ...

That is always a danger.  Mixing C implementations on a single system
is generally unsafe.  There are many implementation-dependent aspects
of C, and if two different compilers embody two different choices they
may produce object modules that are incompatible.

>Question: What is the standard (ANSI) type of an 'enum' constant?
>	  The ANSI-C standard just says ...

You just answered your own question.

>Some compilers determine the type based on the number of constants 
>in the 'enum' type. Some compilers provide an option to set the
>enum constants to 'int's.
>So what is the correct way of implementing 'enum'.

Both those alternatives are valid, as are some other possibilities.
What is invalid is for "enum" to be treated as a type incompatible
with integer operations.  At least one release of PCC did that, and
drove a lot of programmers up the wall.