How to transmit the value of an enumeration

From	pozz <pozzugno@gmail.com>
Newsgroups	comp.arch.embedded
Subject	How to transmit the value of an enumeration
Date	2018-10-24 13:18 +0200
Organization	A noiseless patient Spider
Message-ID	<pqpkdn$ed3$1@dont-email.me> (permalink)

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enum type_t {
   TYPE_1,
   TYPE_2,
   ...
   TYPE_100,
}

void tx_byte(unsigned char c);

enum type_t t;
...
tx_byte((unsigned char)t);


If the maximum value in the enumeration is lower than 256, you can cast 
to (unsigned char) and transmit it as a byte.


However the receiver must have the same enumeration.  The transmitter 
and the receiver must agreed on *the exact values* of the enumeration.

What happens if the developer of the transmitter thinks that it is 
better to swap some values during a future release?  The enumeration 
isn't used only for transmission, it is also used for general logic of 
the software.

Until now I didn't found a good solution.  I only write some comments 
before the enumeration declaration:

/* WARNING!! DON'T CHANGE THE ORDER OF THE VALUES INSIDE ENUMERATION
  * They are also used in the transmission */

I sometimes prefer explicit the value transmitted:

if (t == TYPE_1) tx_byte(0);
if (t == TYPE_2) tx_byte(1);
...


What is your strategy?

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Thread

How to transmit the value of an enumeration pozz <pozzugno@gmail.com> - 2018-10-24 13:18 +0200
  Re: How to transmit the value of an enumeration Jack <jack4747@gmail.com> - 2018-10-24 04:45 -0700
    Re: How to transmit the value of an enumeration pozz <pozzugno@gmail.com> - 2018-10-24 15:18 +0200
      Re: How to transmit the value of an enumeration David Brown <david.brown@hesbynett.no> - 2018-10-24 17:05 +0200
  Re: How to transmit the value of an enumeration David Brown <david.brown@hesbynett.no> - 2018-10-24 15:10 +0200
    Re: How to transmit the value of an enumeration pozz <pozzugno@gmail.com> - 2018-10-24 15:27 +0200
      Re: How to transmit the value of an enumeration David Brown <david.brown@hesbynett.no> - 2018-10-24 16:59 +0200
      Re: How to transmit the value of an enumeration Clifford Heath <no.spam@please.net> - 2018-10-25 08:57 +1100
  Re: How to transmit the value of an enumeration Joe Chisolm <jchisolm6@earthlink.net> - 2018-10-24 12:48 -0500
    Re: How to transmit the value of an enumeration pozz <pozzugno@gmail.com> - 2018-10-24 23:20 +0200
      Re: How to transmit the value of an enumeration Joe Chisolm <jchisolm6@earthlink.net> - 2018-10-24 22:21 -0500
    Re: How to transmit the value of an enumeration David Brown <david.brown@hesbynett.no> - 2018-10-25 09:31 +0200
      Re: How to transmit the value of an enumeration Rob Gaddi <rgaddi@highlandtechnology.invalid> - 2018-10-25 09:58 -0700
      Re: How to transmit the value of an enumeration Joe Chisolm <jchisolm6@earthlink.net> - 2018-10-25 18:38 -0500
        Re: How to transmit the value of an enumeration David Brown <david.brown@hesbynett.no> - 2018-10-26 09:24 +0200
  Re: How to transmit the value of an enumeration George Neuner <gneuner2@comcast.net> - 2018-10-24 15:19 -0400
  Re: How to transmit the value of an enumeration Les Cargill <lcargill99@comcast.com> - 2018-10-26 20:30 -0500

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