copy-constructor.cpp:12:4: error: [iterator-checker] Potentially invalid iterator used.
  *it;
   ^
copy-constructor.cpp:13:4: error: [iterator-checker] Potentially invalid iterator used.
  *copy_it;
   ^
copy-constructor.cpp:23:4: error: [iterator-checker] Potentially invalid iterator used.
  *copy_it;
   ^
3 errors generated.