Method empty

Marlin/src/core/mstring.h:278–278

  int length() const { return strlen(str); }
  int glyphs() { return utf8_strlen(str); }
  bool empty() { return !str[0]; }

  // Quick hash to detect change (e.g., to avoid expensive drawing)
  typedef IF<ENABLED(DJB2_HASH), uint32_t, uint16_t>::type hash_t;