The base template for std::char_traits is deprecated in Xcode 16.4 (after being too hastily removed in 16.3)

[Mike Kaganski]

On 5/19/2025 10:28 AM, Ilmari Lauhakangas wrote:
> Included at the end of this post are the non-standard uses I found in 
> our code base.
>
> ...
>
> include/o3tl/string_view.hxx:128:template <typename charT, typename 
> traits = std::char_traits<charT>>
> include/o3tl/string_view.hxx:167:template <typename charT, typename 
> traits = std::char_traits<charT>>
> include/o3tl/string_view.hxx:237:template <typename charT, typename 
> traits = std::char_traits<charT>>
> include/o3tl/string_view.hxx:247:template <typename charT, typename 
> traits = std::char_traits<charT>>
> include/o3tl/string_view.hxx:256:template <typename charT, typename 
> traits = std::char_traits<charT>>
> include/o3tl/string_view.hxx:265:template <typename charT, typename 
> traits = std::char_traits<charT>>
> include/o3tl/string_view.hxx:276:template <typename charT, typename 
> traits = std::char_traits<charT>>
> include/o3tl/string_view.hxx:285:template <typename charT, typename 
> traits = std::char_traits<charT>>
> include/o3tl/string_view.hxx:318:template <typename charT, typename 
> traits = std::char_traits<charT>>
> include/o3tl/string_view.hxx:331:template <typename charT, typename 
> traits = std::char_traits<charT>>
> include/o3tl/string_view.hxx:343:template <typename charT, typename 
> traits = std::char_traits<charT>>
> include/o3tl/string_view.hxx:355:template <typename charT, typename 
> traits = std::char_traits<charT>>
> include/o3tl/string_view.hxx:368:template <typename charT, typename 
> traits = std::char_traits<charT>>
> include/o3tl/string_view.hxx:380:template <typename charT, typename 
> traits = std::char_traits<charT>>
> include/o3tl/string_view.hxx:436:template <typename charT, typename 
> traits = std::char_traits<charT>>
> sal/rtl/strtmpl.hxx:156:        return std::char_traits<T>::length(pStr);
> sal/rtl/strtmpl.hxx:416:            cursor = 
> std::char_traits<sal_Unicode>::find(cursor, end - cursor, *pSubStr);

Note that these would only be non-standard, if any of charT, T, 
sal_Unicode would happen to be not among "char, wchar_t, char8_t, 
char16_t, char32_t or a custom character type for which you specialized 
std::char_traits". For our code, they are always standard.


-- 

Best regards,

Mike Kaganski