cc -pthread  -Wall -Wextra -Werror=implicit-function-declaration wchar/swprintf.c -o wchar/swprintf -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE -lm -lpthread -lrt -lintl -liconv
wchar/swprintf.c: In function ‘main’:
wchar/swprintf.c:12:19: error: implicit declaration of function ‘swprintf’; did you mean ‘snprintf’? [-Wimplicit-function-declaration]
   12 |         int ret = swprintf(buffer, sizeof(buffer)/sizeof(buffer[0]),
      |                   ^~~~~~~~
      |                   snprintf