cc -pthread  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations locale/newlocale.c -o locale/newlocale -D_POSIX_C_SOURCE=202405L  -lm -lpthread  -liconv
locale/newlocale.c:5:12: error: type specifier missing, defaults to 'int' [-Werror,-Wimplicit-int]
locale_t (*foo)(int, const char *, locale_t) = newlocale;
           ^
locale/newlocale.c:5:36: error: type specifier missing, defaults to 'int' [-Werror,-Wimplicit-int]
locale_t (*foo)(int, const char *, locale_t) = newlocale;
                                   ^
locale/newlocale.c:5:1: error: type specifier missing, defaults to 'int' [-Werror,-Wimplicit-int]
locale_t (*foo)(int, const char *, locale_t) = newlocale;
^
locale/newlocale.c:5:10: error: function cannot return function type 'int (int, const char *, int)'
locale_t (*foo)(int, const char *, locale_t) = newlocale;
         ^
locale/newlocale.c:5:48: error: use of undeclared identifier 'newlocale'; did you mean 'setlocale'?
locale_t (*foo)(int, const char *, locale_t) = newlocale;
                                               ^~~~~~~~~
                                               setlocale
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/locale.h:53:8: note: 'setlocale' declared here
char            *setlocale(int, const char *);
                 ^
5 errors generated.