Re: [PATCH 1/1] Add a helper to reverse index_pos_to_insert_pos()

> On Wed, 9 Oct 2019, Junio C Hamano wrote:
>
>> Johannes Schindelin <Johannes.Schindelin@gmx.de> writes:
>>
>> > FWIW I actually agree with Junio about the helper, but in hindsight I
>> > could have used a better name (not one that is tied to the "index").
>> > Something like `unsigned_one_complement()`. But of course, that would
>> > say _what_ it does, not _why_.
>>
>> I personally feel that the particular name is on the better side of
>> the borderline.  "st_add3(a, b, c)" says it is about adding three
>> size_t quantities, without saying why it exists and should be used
>> over a+b+c.  Existence of the helper and calling it alone should be
>> a good enough sign that we somehow feel a+b+c is not sufficient [ly
>> safe], so we do not call it st_add3_safe() or st_add3_wo_overflow().
>>
>> Your unsigned-one-complement would fall into the same category, no?
>
> Yes. That's what I meant to say with the "what vs why" argument.