title: Advantages of auto in template parameters in C++17
body: <p>What are the advantages of <code>auto</code> in template parameters that will (possibly) be introduced with C++17?</p>
  
  <p>Is it just a natural extension of <code>auto</code> when I want to instantiate template code?</p>
  
  <pre><code>auto v1 = constant&lt;5&gt;;      // v1 == 5, decltype(v1) is int
  auto v2 = constant&lt;true&gt;;   // v2 == true, decltype(v2) is bool
  auto v3 = constant&lt;'a'&gt;;    // v3 == 'a', decltype(v3) is char
  </code></pre>
  
  <p>What else do I gain from this language feature?</p>