22 General utilities library [utilities]

22.8 Expected objects [expected]

22.8.2 Header <expected> synopsis [expected.syn]

namespace std { // [expected.unexpected], class template unexpected template<class E> class unexpected; // [expected.bad], class template bad_­expected_­access template<class E> class bad_expected_access; // [expected.bad.void], specialization for void template<> class bad_expected_access<void>; // in-place construction of unexpected values struct unexpect_t { explicit unexpect_t() = default; }; inline constexpr unexpect_t unexpect{}; // [expected.expected], class template expected template<class T, class E> class expected; // [expected.void], partial specialization of expected for void types template<class T, class E> requires is_void_v<T> class expected<T, E>; }