Am 04.10.19 um 11:55 schrieb Johannes Schindelin:
> On Fri, 4 Oct 2019, Junio C Hamano wrote:
>> These three look good and too similar to each other, which makes me
>> wonder if we want to allow them simply write
>>
>> return insert_pos_as_negative_offset(nr);
>>
>> with something like
>>
>> static int insert_pos_as_negative_offset(uintmax_t nr)
>> {
>> if (INT_MAX < nr)
>> die("overflow: -1 - %"PRIuMAX, nr);
>> return -1 - (int)nr;
>> }
>>
>> to avoid repetition.
>
> I tried not to do that because there are two different data types in
> play: `unsigned int` and `size_t`. But I guess by making this an
> `inline` function, compilers can optimize for the common case and avoid
> casting _twice_.
>
> Will be fixed in v2,
IMHO, if you don't accompany insert_pos_as_negative_offset() with a
corresponding extract_pos_and_found_condition() and use it everywhere,
it is more obfuscating than necessary.
The *real* problem to solve is to ensure that the index/cache does not
grow so large that 32-bit indexes would be needed. Then the calculation
that you want to hide here cannot overflow.
-- Hannes
