fusl/src/ctype/isdigit.c

#include <ctype.h>
#include "libc.h"
#undef isdigit

int isdigit(int c) {
  return (unsigned)c - '0' < 10;
}

int __isdigit_l(int c, locale_t l) {
  return isdigit(c);
}

weak_alias(__isdigit_l, isdigit_l);