cc -pthread  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations wchar/vswscanf.c -o wchar/vswscanf -D_POSIX_C_SOURCE=202405L -lm -lpthread -lrt -lintl -liconv
wchar/vswscanf.c:5:73: error: ‘vswscanf’ undeclared here (not in a function)
    5 | int (*foo)(const wchar_t *restrict, const wchar_t *restrict, va_list) = vswscanf;
      |                                                                         ^~~~~~~~