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std::bad_expected_access(3) C++ Standard Libary std::bad_expected_access(3)

NAME

std::bad_expected_access - std::bad_expected_access

Synopsis


Defined in header <expected>
template< class E > (1) (since C++23)
class bad_expected_access : public std::bad_expected_access<void>
template<> (2) (since C++23)
class bad_expected_access<void> : public std::exception


1) Defines a type of object to be thrown by std::expected::value when accessing an
expected object that contains an unexpected value. bad_expected_access<E> stores a
copy of the unexpected value.
2) bad_expected_access<void> is the base class of all other bad_expected_access
specializations.


This section is incomplete
Reason: inheritance diagram

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().


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.

Example


This section is incomplete
Reason: no example

Categories:


* Todo with reason
* Todo no example

2024.06.10 http://cppreference.com