17 Language support library [support]

17.9 Exception handling [support.exception]

17.9.4 Class bad_exception [bad.exception]

namespace std { class bad_exception : public exception { public: // see [exception] for the specification of the special member functions const char* what() const noexcept override; }; }
The class bad_exception defines the type of the object referenced by the exception_ptr returned from a call to current_exception ([propagation]) when the currently active exception object fails to copy.
const char* what() const noexcept override;
Returns: An implementation-defined ntbs.