cc -pthread  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations wchar/fgetwc.c -o wchar/fgetwc -D_POSIX_C_SOURCE=202405L -lm -lpthread -lrt -lintl -liconv
wchar/fgetwc.c:5:25: error: ‘fgetwc’ undeclared here (not in a function)
    5 | wint_t (*foo)(FILE *) = fgetwc;
      |                         ^~~~~~