33 class expected {
35     constexpr expected() = default;
36     constexpr expected(const expected& rhs) = default;
37     constexpr expected(expected&& rhs) = default;
40     constexpr expected(T&& v)  in expected()  function
44     constexpr expected(std::in_place_t, Args&&... args)  in expected()  function
47     constexpr expected(const unexpected<E>& u)  in expected()  function
51     constexpr expected(const unexpected<OtherE>& e)  in expected()  function
79     constexpr expected<T, NewE> transform_error(F&& function) {  in transform_error()
82                 return expected<T, NewE>();  in transform_error()
84                 return expected<T, NewE>(std::in_place, value());  in transform_error()