message: das.tuple: Fix hashing.
diff: @@ -71,12 +71,13 @@ namespace elle
  {
  // This should be a lambda in hash_value, but GCC 4.8 says no:
  // "sorry, unimplemented: mangling argument_pack_select"
  + using boost::hash_value;
  template <typename S, typename T>
  inline
  void
  _hash_tuple(T const& t, std::size_t& seed)
  {
  - boost::hash_combine(seed, boost::hash_value(S::attr_get(t)));
  + boost::hash_combine(seed, hash_value(S::attr_get(t)));
  };
  }
  