22 General utilities library [utilities]

22.5 Optional objects [optional]

22.5.5 Class bad_­optional_­access [optional.bad.access]

namespace std { class bad_optional_access : public exception { public: // see [exception] for the specification of the special member functions const char* what() const noexcept override; }; }
The class bad_­optional_­access defines the type of objects thrown as exceptions to report the situation where an attempt is made to access the value of an optional object that does not contain a value.
const char* what() const noexcept override;
Returns: An implementation-defined ntbs.