wcsncpy
=======

POSIX specification:
 https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcsncpy.html

Gnulib module: wcsncpy

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  * On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

Note: This function has no real use: It cannot be used for filling a fixed-size record with a wide string, before writing it to a file, because the wide string encoding is platform dependent and, on some platforms, also locale dependent. And this function is not appropriate for copying a wide string into a bounded memory area, because you have no guarantee that the result will be null-terminated. Even if you add the null character at the end yourself, this function is inefficient (as it spends time clearing unused memory) and will allow silent truncation to occur, which is not a good behavior for GNU programs.