title: why auto i = same_const_variable could not deduce "const"?
body: <pre><code>const int ci = 10;
  auto i = ci;  // i will be "int" instead of "const int"
  i = 20;
  </code></pre>
  
  <p>I am wondering why auto is designed for this kind of behaviour?</p>
  
  <p>why the type i is "int" instead of "const int" ? </p>
  
  <p>what is the concern here?</p>
  
  <p>I think understand why will help us to remember it</p>