C11-generic.c

#define __format(arg) _Generic((arg), \
                      char: "%c", \
               signed char: "%hhd", \
             unsigned char: "%hhu", \
              signed short: "%hd", \
            unsigned short: "%hu", \
                signed int: "%d", \
              unsigned int: "%u", \
                  long int: "%ld", \
         unsigned long int: "%lu", \
             long long int: "%lld", \
    unsigned long long int: "%llu", \
                     _Bool: "%d", \
                     float: "%g", \
                    double: "%g", \
               long double: "%Lg", \
           _Complex double: "%g + %gi", \
                    char *: "%s", \
                    void *: "%p", \
         char[sizeof(arg)]: "%s", \
                   default: "<unknown>" \
)

/* Print an argument regardless of its type (see __format). */
#define __print_arg(arg) printf(__format(arg), arg)