message: tuple: Simplify printing.
diff: @@ -8,19 +8,14 @@ namespace std
  namespace
  {
  template <int idx, typename T>
  - std::enable_if_t<idx == tuple_size<T>::value, void>
  - print_tuple(std::ostream&, T const&, bool)
  - {};
  -
  - template <int idx, typename T>
  - std::enable_if_t<idx < tuple_size<T>::value, void>
  + void
  print_tuple(std::ostream& s, T const& v, bool first)
  {
  - if (!first)
  - elle::print(s, ", %s", get<idx>(v));
  - else
  - elle::print(s, "%s", get<idx>(v));
  + if constexpr(idx < tuple_size<T>::value)
  + {
  + elle::print(s, first ? "{}" : ", {}", get<idx>(v));
  print_tuple<idx + 1, T>(s, v, false);
  + }
  };
  }
  