int main(void) {
  char* ar1 = "Hello";
  char ar2[] = "HEllo";

  char* arr3[] = {"Cat", "Bag", "Kas", "Zzd"};
  char** ar4 = {"Cat", "Bag", "Kas", "Zzd"};
  return 0;
}

cc1plus: warnings being treated as errors
In function 'int main()':
Line 2: warning: deprecated conversion from string constant to 'char*''
Line 5: warning: deprecated conversion from string constant to 'char*''
Line 5: warning: deprecated conversion from string constant to 'char*''
Line 5: warning: deprecated conversion from string constant to 'char*''
Line 5: warning: deprecated conversion from string constant to 'char*''
Line 6: error: scalar object 'ar4' requires one element in initializer
compilation terminated due to -Wfatal-errors.