struct String8 {
  u8* str;
  u64 size;

  const char *c() const { return reinterpret_cast<const char *>(str); }
  u8 operator[](u64 idx) const { return str[idx]; }
};

#define str8(s) String8 { (u8*)(s), sizeof(s) - 1 }

String8 str8_from_c(const char *str);
String8 push_str8f(Arena *arena, char *fmt, ...);