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Re: [Cbor] Benjamin Kaduk's No Objection on draft-ietf-cbor-network-addresses-09: (with COMMENT)

Benjamin Kaduk <kaduk@mit.edu> Thu, 07 October 2021 19:57 UTC

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Date: Thu, 07 Oct 2021 12:57:01 -0700
From: Benjamin Kaduk <kaduk@mit.edu>
To: Michael Richardson <mcr+ietf@sandelman.ca>
Cc: Carsten Bormann <cabo@tzi.org>, draft-ietf-cbor-network-addresses@ietf.org, Barry Leiba <barryleiba@computer.org>, cbor@ietf.org, The IESG <iesg@ietf.org>, cbor-chairs@ietf.org
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Subject: Re: [Cbor] Benjamin Kaduk's No Objection on draft-ietf-cbor-network-addresses-09: (with COMMENT)
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On Thu, Oct 07, 2021 at 02:55:55PM -0400, Michael Richardson wrote:
> 
> Benjamin Kaduk <kaduk@mit.edu> wrote:
>     > On Wed, Oct 06, 2021 at 04:41:40PM -0400, Michael Richardson wrote:
>     >>
>     >> Carsten Bormann <cabo@tzi.org> wrote:
>     >> >> unused_bits = (8 - (prefix_length_in_bits & 7)) % 8;
>     >>
>     >> > Well, I for one don’t like making the “simply” more complicated (*).
>     >>
>     >> I have no strong preference.
>     >> If I didn't have to read/write C again in my life, that would be fine.
> 
>     > I'm sure many share that sentiment :)
> 
> okay, so
>   unused_bits = (8 - (prefix_length_in_bits % 8);
> 
> produces the wrong answer (8) when it's a multiple of 8 and the answer should
> be 0.
> 
>   unused_bits = (8 - (prefix_length_in_bits % 8) % 8;
> 
> gives the right answer.  Can I use that?

In light of the discussion so far, that expression would be my
proposal/recommendation.

-Ben

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