class customArray {
  public:
    int data[10];
    customArray() {
      for (auto&& d : data) d = 7;
    }
    void print() {
      for (auto&& d : data) {
        Serial.print(d); Serial.write(' ');
      }
      Serial.println();
    }
    customArray& operator=(const int(&arr)[10]) {
      for (int i = 0; i < sizeof arr / sizeof *arr; ++i) {
        data[i] = arr[i];
      }
      return *this;
    }
} ;

customArray a1;

void setup() {
  Serial.begin(115200);
  a1.print();
  a1 = {1, 2, 3, 4, 5, 6, 7, 8, 9, 0};
  a1.print();
}

void loop() {}