cc -pthread -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations wctype/iswalpha_l.c -o wctype/iswalpha_l -D_POSIX_C_SOURCE=202405L -lm -lpthread -liconv wctype/iswalpha_l.c:5:20: error: type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int [-Wimplicit-int] 5 | int (*foo)(wint_t, locale_t) = iswalpha_l; | ^ | int wctype/iswalpha_l.c:5:32: error: use of undeclared identifier 'iswalpha_l'; did you mean 'iswalpha'? 5 | int (*foo)(wint_t, locale_t) = iswalpha_l; | ^~~~~~~~~~ | iswalpha /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/___wctype.h:87:1: note: 'iswalpha' declared here 87 | iswalpha(wint_t _wc) | ^ wctype/iswalpha_l.c:5:7: error: incompatible function pointer types initializing 'int (*)(wint_t, int)' (aka 'int (*)(int, int)') with an expression of type 'int (wint_t)' (aka 'int (int)') [-Wincompatible-function-pointer-types] 5 | int (*foo)(wint_t, locale_t) = iswalpha_l; | ^ ~~~~~~~~~~ 3 errors generated.