cc -pthread  -Wall -Wextra -Werror=implicit-function-declaration wchar/vswprintf.c -o wchar/vswprintf -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE -lm -lpthread -lrt -lintl -liconv
wchar/vswprintf.c: In function ‘indirect’:
wchar/vswprintf.c:15:19: error: implicit declaration of function ‘vswprintf’; did you mean ‘vsnprintf’? [-Wimplicit-function-declaration]
   15 |         int ret = vswprintf(buffer, sizeof(buffer)/sizeof(buffer[0]), format, ap);
      |                   ^~~~~~~~~
      |                   vsnprintf