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From:   Junio C Hamano <gitster@pobox.com>
To:     Martin =?utf-8?Q?=C3=85gren?= <martin.agren@gmail.com>
Cc:     git@vger.kernel.org,
        =?utf-8?B?Tmd1eeG7hW4gVGjDoWkgTmfhu41j?= Duy <pclouds@gmail.com>
Subject: Re: [PATCH 09/11] read-cache: require flags for `write_locked_index()`
References: <cover.1506862824.git.martin.agren@gmail.com>
        <d912e33a1395ff25c1496715d0a537858daa885a.1506862824.git.martin.agren@gmail.com>
Date:   Mon, 02 Oct 2017 12:49:11 +0900
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        ("Martin =?utf-8?Q?=C3=85gren=22's?= message of "Sun, 1 Oct 2017 16:56:10
 +0200")
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Martin =C3=85gren <martin.agren@gmail.com> writes:

> ... Instead, require that one of the
> flags is set. Adjust documentation and the assert we already have for
> checking that we don't have too many flags. Add a macro `HAS_SINGLE_BIT=
`
> (inspired by `HAS_MULTI_BITS`) to simplify this check and similar check=
s
> in the future.

I do not have a strong opinion against this approach, but if
something can take only one of two values, wouldn't it make more
sense to express it as a single boolean, I wonder.  Then there is no
need to invent a cute HAS_SINGLE_BIT() macro, either.

"commit and leave it open" cannot be expressed with such a scheme,
but with the HAS_SINGLE_BIT() scheme it can't anyway, so...