https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114731
--- Comment #14 from Alejandro Colomar <alx at kernel dot org> --- Oops, I forgot to paste the version with casts. Here it is. It is too repetitive and error prone. alx@debian:~/tmp/c$ cat g.c #include <assert.h> #include <bsd/inttypes.h> #include <errno.h> #include <time.h> #define is_same_type(a, b) __builtin_types_compatible_p(a, b) #define is_same_typeof(a, b) is_same_type(typeof(a), typeof(b)) #define a2i(TYPE, n, s, endp, base, min, max) \ ({ \ _Static_assert(is_same_typeof(TYPE *, n), ""); \ _Generic((TYPE) 0, \ long: a2sl((long *) n, s, endp, base, min, max), \ int: a2si( (int *) n, s, endp, base, min, max) \ ); \ }) #define a2sl(n, s, endp, base, min, max) \ ( \ _Generic(endp, \ const char **: a2sl_c, \ char **: a2sl_nc, \ void *: a2sl_nc \ )(n, s, endp, base, min, max) \ ) #define a2si(n, s, endp, base, min, max) \ ( \ _Generic(endp, \ const char **: a2si_c, \ char **: a2si_nc, \ void *: a2si_nc \ )(n, s, endp, base, min, max) \ ) static inline int a2sl_c(long *restrict n, const char *s, const char **restrict endp, int base, long min, long max); static inline int a2si_c(int *restrict n, const char *s, const char **restrict endp, int base, int min, int max); static inline int a2sl_nc(long *restrict n, const char *s, char **restrict endp, int base, long min, long max); static inline int a2si_nc(int *restrict n, const char *s, char **restrict endp, int base, int min, int max); static inline int a2sl_c(long *restrict n, const char *s, const char **restrict endp, int base, long min, long max) { return a2sl_nc(n, s, (char **) endp, base, min, max); } static inline int a2si_c(int *restrict n, const char *s, const char **restrict endp, int base, int min, int max) { return a2si_nc(n, s, (char **) endp, base, min, max); } static inline int a2sl_nc(long *restrict n, const char *s, char **restrict endp, int base, long min, long max) { int status; *n = strtoi(s, endp, base, min, max, &status); if (status != 0) { errno = status; return -1; } return 0; } static inline int a2si_nc(int *restrict n, const char *s, char **restrict endp, int base, int min, int max) { int status; *n = strtoi(s, endp, base, min, max, &status); if (status != 0) { errno = status; return -1; } return 0; } int main(void) { time_t t; a2i(time_t, &t, "42", NULL, 0, 0, 10); } alx@debian:~/tmp/c$ cc -Wall -Wextra g.c -S alx@debian:~/tmp/c$