title: Is it possible to turn a constexpr std::array into a std::integer_sequence?
body: <p>That is, given a <code>constexpr std::array&lt;int,2&gt;{1,2}</code> pass it to some function or helper class that would spit out the type <code>std::integer_sequence&lt;int, 1, 2&gt;</code>?</p>
  
  <p>It seems easy to jump from the type world to the "constexpr value" world (e.g., to do the reverse conversion), but hard or impossible to do the reverse.</p>