cc -pthread  -Wall -Wextra -Werror=implicit-function-declaration wctype/iswdigit_l.c -o wctype/iswdigit_l -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE  -lm -lpthread  -liconv
wctype/iswdigit_l.c:15:8: error: call to undeclared function 'iswdigit_l'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
   15 |         if ( !iswdigit_l(wc1, locale) )
      |               ^
wctype/iswdigit_l.c:15:8: note: did you mean 'iswdigit'?
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/___wctype.h:108:1: note: 'iswdigit' declared here
  108 | iswdigit(wint_t _wc)
      | ^
1 error generated.