cc -pthread  -Wall -Wextra -Werror=implicit-function-declaration wchar/vwscanf.c -o wchar/vwscanf -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE -lm -lpthread -lrt -lintl -liconv
wchar/vwscanf.c: In function ‘indirect’:
wchar/vwscanf.c:18:14: error: implicit declaration of function ‘fputws’; did you mean ‘fputs’? [-Wimplicit-function-declaration]
   18 |         if ( fputws(L"hello world 42", stdout) == -1 )
      |              ^~~~~~
      |              fputs
wchar/vwscanf.c:23:19: error: implicit declaration of function ‘vwscanf’; did you mean ‘vsscanf’? [-Wimplicit-function-declaration]
   23 |         int ret = vwscanf(format, ap);
      |                   ^~~~~~~
      |                   vsscanf