title: struct to/from std::tuple conversion
body: <p>Assuming I have <code>struct</code> and <code>std::tuple</code> with same type layout:</p>
  
  <pre><code>struct MyStruct { int i; bool b; double d; }
  using MyTuple = std::tuple&lt;int,bool,double&gt;;
  </code></pre>
  
  <p>Is there any standartized way to cast one to another?</p>
  
  <p>P.S. I know that trivial memory copying can do the trick, but it is alignment and implementation dependent</p>