cc -pthread   -Wall -Wextra -Werror=implicit-function-declaration wchar/vfwscanf.c -o wchar/vfwscanf -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE -lm -lpthread -lrt  -lintl -liconv
wchar/vfwscanf.c: In function ‘indirect’:
wchar/vfwscanf.c:15:14: error: implicit declaration of function ‘fputws’; did you mean ‘fputs’? [-Wimplicit-function-declaration]
   15 |         if ( fputws(L"hello world 42", fp) == -1 )
      |              ^~~~~~
      |              fputs
wchar/vfwscanf.c:21:19: error: implicit declaration of function ‘vfwscanf’; did you mean ‘vfscanf’? [-Wimplicit-function-declaration]
   21 |         int ret = vfwscanf(fp, format, ap);
      |                   ^~~~~~~~
      |                   vfscanf