* Jonathan Wakely:
> On Wed, 24 May 2023 at 10:06, Florian Weimer wrote:
>>
>> * Jonathan Wakely via Gcc:
>>
>> >> It seems it might even be trivial enough for me to investigate and
>> >> tackle myself, in some spare time.
>> >>
>> >> I see very little code using either of these features, so it's
>> >> definitely not a high priority task regardless.
>> >>
>> >
>> > Glibc uses the nonnull attribute in many places. Libstdc++ uses it in a few
>> > places.
>>
>> Note that the glibc uses are frequently incompatible with libstdc++
>
> Do you mean incompatible with libstdc++ specifically, or incompatible
> with "common C++ idioms"?
The latter (common C++ idioms as encouraged by the standard library).
>> (std::vector in particular). Unfortunately, there is no consensus to
>> fix this. For example, one issue is that
>>
>> memset(vec.data(), 0, sizeof(decltype(vec)::value_type) * vec.size())
>>
>> isn't necessarily defined even for vectors of POD type.
>
> It's not really idiomatic C++ code anyway. Why would you write that,
> instead of:
>
> vec.assign(vec.size(), {});
> or:
> std::fill_n(vec.begin(), vec.size(), range_value_t<decltype(vec)>:{});
> ?
>
> (The latter optimizes to the ideal code, but I think I know how to
> make the former optimize to the same thing.)
Well, one might be tempted to write that explicit memset to eliminate
the conditional branch, except that it's technically required because
data() might return nullptr. 8-/
Thanks,
Florian
