copy constructor start
      1.0000      1.0000      1.0000
      2.0000      2.0000      2.0000
      3.0000      3.0000      3.0000
      4.0000      4.0000      4.0000
copy constructor ends
copy constructor start
*** Error in `./test': malloc(): memory corruption: 0x00000000006dc1a0 ***