cpp/string/wide/wcsncpy

Copies at most characters of the wide string pointed to by  (including the terminating null wide character) to wide character array pointed to by.

If is reached before the entire string  was copied, the resulting wide character array is not null-terminated.

If, after copying the terminating null wide character from, is not reached, additional null wide characters are written to  until the total of  characters have been written.

If the strings overlap, the behavior is undefined.