Re: questions following upcoming POSIX issue 8 release - wmemrchr

[Bruno Haible]

Eric Blake wrote:
> - https://austingroupbugs.net/view.php?id=1633
> The bug mentions both memrchr() and wmemrchr() as possible candidates
> for standardization, but the Austin Group would rather standardize
> only memrchr() (can anyone even think of software where a proposed
> wmemrchr() would be useful?)

* No system has wmemrchr so far. This can be seen
  - through a web search for wmemrchr, or
  - in Gnulib's symbol database
    
https://git.savannah.gnu.org/gitweb/?p=gnulib/maint-tools.git;a=tree;f=platforms/various-symlists

* wchar_t based APIs have severe problems
  https://www.gnu.org/software/gnulib/manual/html_node/The-wchar_005ft-type.html
  which have discouraged programmers on POSIX systems from using these
  APIs for two decades. Better APIs can be constructed on top of the
  char32_t type.[1][2]
  Therefore, it makes no sense to add new APIs based on wchar_t, given
  that the entire wchar_t system was a failure.

Bruno

[1] 
https://www.gnu.org/software/gnulib/manual/html_node/Comparison-of-string-APIs.html
[2] 
https://www.gnu.org/software/gnulib/manual/html_node/Comparison-of-character-APIs.html