Class unexpected

crates/cpp/test_headers/expected.hpp:142–169

#endif

template <class E> class unexpected {
public:
  static_assert(!std::is_same<E, void>::value, "E must not be void");

  unexpected() = delete;
  constexpr explicit unexpected(const E &e) : m_val(e) {}

  constexpr explicit unexpected(E &&e) : m_val(std::move(e)) {}

  template <class... Args, typename std::enable_if<std::is_constructible<
                               E, Args &&...>::value>::type * = nullptr>
  constexpr explicit unexpected(Args &&...args)
      : m_val(std::forward<Args>(args)...) {}
  template <
      class U, class... Args,
      typename std::enable_if<std::is_constructible<
          E, std::initializer_list<U> &, Args &&...>::value>::type * = nullptr>
  constexpr explicit unexpected(std::initializer_list<U> l, Args &&...args)
      : m_val(l, std::forward<Args>(args)...) {}

  constexpr const E &value() const & { return m_val; }
  TL_EXPECTED_11_CONSTEXPR E &value() & { return m_val; }
  TL_EXPECTED_11_CONSTEXPR E &&value() && { return std::move(m_val); }
  constexpr const E &&value() const && { return std::move(m_val); }

private:
  E m_val;
};

#ifdef __cpp_deduction_guides
template <class E> unexpected(E) -> unexpected<E>;