cc -pthread  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations wchar/vwscanf.c -o wchar/vwscanf -D_POSIX_C_SOURCE=202405L -lm -lpthread -lrt -lintl -liconv
wchar/vwscanf.c:5:48: error: ‘vwscanf’ undeclared here (not in a function)
    5 | int (*foo)(const wchar_t *restrict, va_list) = vwscanf;
      |                                                ^~~~~~~