#include <iostream>

class TestClass {
public:
  TestClass(){
    arr1[0] = new Double_t[66];
    Double_t **arr2 = arr1[0];
    arr1[0][0]= 123.;
    std::cout << "arr1[0][0]: " << arr1[0][0] <<std::endl;
    std::cout << "arr2[0][0]: " << arr2[0][0] <<std::endl;
  }
  ~TestClass(){
    delete[] arr1[0];
  }
private:
    Double_t* arr1[1];
};

void double_pointer_segv() {
  TestClass ts;
}