namespace std {
class bad_typeid : public exception {
public:
bad_typeid() noexcept;
bad_typeid(const bad_typeid&) noexcept;
bad_typeid& operator=(const bad_typeid&) noexcept;
const char* what() const noexcept override;
};
}The class bad_typeid defines the type of objects thrown as exceptions by the implementation to report a null pointer in a typeid expression ([expr.typeid]).
bad_typeid() noexcept;
bad_typeid(const bad_typeid&) noexcept;
bad_typeid& operator=(const bad_typeid&) noexcept;
const char* what() const noexcept override;
Remarks: The message may be a null-terminated multibyte string, suitable for conversion and display as a wstring ([string.classes], [locale.codecvt])