std::expected<T,E>::value
From cppreference.com
| T is not cv void |
||
| constexpr T& value() &; |
(1) | (since C++23) |
| constexpr const T& value() const&; |
(2) | (since C++23) |
| constexpr T&& value() &&; |
(3) | (since C++23) |
| constexpr const T&& value() const&&; |
(4) | (since C++23) |
| T is cv void |
||
| constexpr void value() const&; |
(5) | (since C++23) |
| constexpr void value() &&; |
(6) | (since C++23) |
If *this contains an expected value, returns an reference to the contained value. Returns nothing if T is (possibly cv-qualified) void.
Otherwise, throws an exception of type std::bad_expected_access<std::decay_t<E>> that contains a copy of error().
3,4,6) If std::is_copy_constructible_v<E> or std::is_constructible_v<E, decltype(std::move(error()))> is false, the program is ill-formed.
Parameters
(none)
Return value
1-4) The expected value contained in *this.
5-6) (none)
Exceptions
1,2,5) Throws std::bad_expected_access(std::as_const(error())) if *this contains an unexpected value.
3,4,6) Throws std::bad_expected_access(std::move(error())) if *this contains an unexpected value.
Example
| This section is incomplete Reason: no example |
See also
| (C++23) |
returns the expected value if present, another value otherwise (public member function) |
| (C++23) |
accesses the expected value (public member function) |
| (C++23) |
returns the unexpected value (public member function) |
| (C++23) |
exception indicating checked access to an expected that contains an unexpected value (class template) |