cc -pthread  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations iconv/iconv_open.c -o iconv/iconv_open -D_POSIX_C_SOURCE=202405L -lm -lpthread -lrt -lintl -liconv
iconv/iconv_open.c:5:46: error: ‘iconv_open’ undeclared here (not in a function); did you mean ‘libiconv_open’?
    5 | iconv_t (*foo)(const char *, const char *) = iconv_open;
      |                                              ^~~~~~~~~~
      |                                              libiconv_open