gcc -pthread  -Wall -Wextra -Werror=implicit-function-declaration iconv/iconv.c -o iconv/iconv -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE -lm -lpthread -lrt -lxnet -lsocket -latomic
iconv/iconv.c: In function 'main':
iconv/iconv.c:30:37: error: passing argument 2 of 'iconv' from incompatible pointer type [-Wincompatible-pointer-types]
   30 |         size_t result = iconv(conv, &input, &input_left, &output, &output_left);
      |                                     ^~~~~~
      |                                     |
      |                                     char **
In file included from iconv/iconv.c:3:
/usr/include/iconv.h:47:32: note: expected 'const char ** restrict' but argument is of type 'char **'
   47 | extern size_t   iconv(iconv_t, const char **_RESTRICT_KYWD,
      |                                ^
iconv/iconv.c:43:30: error: passing argument 2 of 'iconv' from incompatible pointer type [-Wincompatible-pointer-types]
   43 |         result = iconv(conv, &input, &input_left, &output, &output_left);
      |                              ^~~~~~
      |                              |
      |                              char **
/usr/include/iconv.h:47:32: note: expected 'const char ** restrict' but argument is of type 'char **'
   47 | extern size_t   iconv(iconv_t, const char **_RESTRICT_KYWD,
      |                                ^
iconv/iconv.c:64:30: error: passing argument 2 of 'iconv' from incompatible pointer type [-Wincompatible-pointer-types]
   64 |         result = iconv(conv, &input, &input_left, &output, &output_left);
      |                              ^~~~~~
      |                              |
      |                              char **
/usr/include/iconv.h:47:32: note: expected 'const char ** restrict' but argument is of type 'char **'
   47 | extern size_t   iconv(iconv_t, const char **_RESTRICT_KYWD,
      |                                ^