cc -pthread  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations unistd/swab.c -o unistd/swab -D_POSIX_C_SOURCE=202405L -lm -lpthread -lrt -lintl -liconv
unistd/swab.c:11:62: error: ‘swab’ undeclared here (not in a function)
   11 | void (*foo)(const void *restrict, void *restrict, ssize_t) = swab;
      |                                                              ^~~~