cc -pthread  -Wall -Wextra -Werror=implicit-function-declaration wchar/vswscanf.c -o wchar/vswscanf -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE -lm -lpthread -lrt -lintl -liconv
wchar/vswscanf.c: In function ‘indirect’:
wchar/vswscanf.c:12:19: error: implicit declaration of function ‘vswscanf’; did you mean ‘vsscanf’? [-Wimplicit-function-declaration]
   12 |         int ret = vswscanf(L"hello world 42", format, ap);
      |                   ^~~~~~~~
      |                   vsscanf