title: What is the difference between memberwise copy, bitwise copy, shallow copy and deep copy?
body: <p>I have googled these terms but I am still confused.</p>
  <p>Some people said that memberwise copy is deep copy and the bitwise copy is shallow copy but someone said it is not.</p>
  <p>Can anyone explain to me that which type of copy of the default copy constructor and the user-defined copy constructor use?</p>