On Wed, Jun 24, 2026 at 5:37 PM Hubert Tong <
hubert.reinterpretcast_at_[hidden]> wrote:

> On Wed, Jun 24, 2026 at 9:50 AM Corentin Jabot via SG16 <
> sg16_at_[hidden]> wrote:
>
>>
>>
>> On Wed, Jun 24, 2026 at 3:17 AM Steve Downey via SG16 <
>> sg16_at_[hidden]> wrote:
>>
>>
>>> wg21: TODO [[
>>> https://github.com/cplusplus/papers/issues/1572][LWG2959]]
>>> char_traits<char16_t>::eof is a valid UTF-16 code unit
>>> :sg16:
>>>
>>
>> We should ask Louis/STL if they are happy to change int_type, or,
>> alternatively explain LEWG the only solution is to change int_type, and
>> see if they care.
>>
>
> Only for char16_t? Go beyond that, and I think we'll be back in the
> "committee broke std::string ABI" land.
>

Right, both UTF-8 and UTF-32 have invalid values - for example 0xFF and
0xFFFFFFFF can be used as sentinel - so they don;t suffer the issue
described here - but UTF-16 has no such luck, the whole space is used,
either for codepoints, or surrogates.


>
> -- HT
>