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/C++std::bad_optional_access
Defined in header <optional> | ||
|---|---|---|
class bad_optional_access; | (since C++17) |
Defines a type of object to be thrown by std::optional::value when accessing an optional object that does not contain a value.
Inheritance diagram.
Member functions
| (constructor) | constructs a new bad_optional_access object (public member function) |
| operator= | replaces the bad_optional_access object (public member function) |
| what | returns the explanatory string (public member function) |
std::bad_optional_access::bad_optional_access
bad_optional_access() noexcept; | (1) | (since C++17) |
bad_optional_access( const bad_optional_access& other ) noexcept; | (2) | (since C++17) |
Constructs a new bad_optional_access object with an implementation-defined null-terminated byte string which is accessible through what().
*this and other both have dynamic type std::bad_optional_access then std::strcmp(what(), other.what()) == 0.Parameters
| other | - | another exception object to copy |
std::bad_optional_access::operator=
bad_optional_access& operator=( const bad_optional_access& other ) noexcept; | (since C++17) |
Assigns the contents with those of other. If *this and other both have dynamic type std::bad_optional_access then std::strcmp(what(), other.what()) == 0 after assignment.
Parameters
| other | - | another exception object to assign with |
Return value
*this.
std::bad_optional_access::what
virtual const char* what() const noexcept; | (since C++17) |
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().
Inherited from std::exception
Member functions
|
[virtual] | destroys the exception object (virtual public member function of std::exception) |
|
[virtual] | returns an explanatory string (virtual public member function of std::exception) |
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