Difference between revisions of "cpp/utility/expected/bad expected access"
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Latest revision as of 09:48, 17 April 2023
| Defined in header <expected>
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| template< class E > class bad_expected_access : public std::bad_expected_access<void> |
(1) | (since C++23) |
| template<> class bad_expected_access<void> : public std::exception |
(2) | (since C++23) |
bad_expected_access<E> stores a copy of the unexpected value.bad_expected_access<void> is the base class of all other bad_expected_access specializations.| This section is incomplete Reason: inheritance diagram |
Contents |
[edit] Members of the primary template
| (constructor) |
constructs a bad_expected_access object (public member function) |
| error |
returns the stored value (public member function) |
| what |
returns the explanatory string (public member function) |
std::bad_expected_access::bad_expected_access
| explicit bad_expected_access( E e ); |
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Constructs a new bad_expected_access<E> object. Initializes the stored value with std::move(e).
std::bad_expected_access::error
| const E& error() const & noexcept; E& error() & noexcept; |
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Returns a reference to the stored value.
std::bad_expected_access::what
| const char* what() const noexcept override; |
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Returns the explanatory string.
Parameters
(none)
Return value
Pointer to a null-terminated string with explanatory information. The string is suitable for conversion and display as a std::wstring. The pointer is guaranteed to be valid at least until the exception object from which it is obtained is destroyed, or until a non-const member function (e.g. copy assignment operator) on the exception object is called.
Notes
Implementations are allowed but not required to override what().
[edit] Members of the bad_expected_access<void> specialization
| (constructor) |
constructs a bad_expected_access<void> object (protected member function) |
| (destructor) |
destroys the bad_expected_access<void> object (protected member function) |
| operator= |
replaces the bad_expected_access<void> object (protected member function) |
| what |
returns the explanatory string (public member function) |
Special member functions of bad_expected_access<void> are protected. They can only be called by derived classes.
[edit] Example
| This section is incomplete Reason: no example |
