message: make-vector: Enable to define the target type.
diff: @@ -95,14 +95,18 @@ namespace elle
  ///
  /// @param c A container.
  /// @returns A set.
  - template <typename Cont>
  + template <typename R = void,
  + typename Cont>
  auto
  make_vector(Cont&& c)
  - -> std::vector<typename std::remove_reference_t<Cont>::value_type>
  + -> std::conditional_t<
  + std::is_same<R, void>::value,
  + std::vector<typename std::remove_reference_t<Cont>::value_type>,
  + R>
  {
  using std::begin;
  using std::end;
  - using Res = std::vector<typename std::remove_reference_t<Cont>::value_type>;
  + using Res = decltype(make_vector<R, Cont>(std::forward<Cont>(c)));
  return elle::meta::static_if<
  std::is_same<std::remove_reference_t<Cont>, Cont>::value &&
  detail::make_vector_move<std::remove_reference_t<Cont>>::value >(
  