One of two subclasses of exception.
Runtime errors represent problems outside the scope of a program; they cannot be easily predicted and can generally only be caught as the program executes.
|std::runtime_error::runtime_error||(||const string &||__arg||)||
Takes a character string describing the error.
|virtual const char* std::runtime_error::what||(||)|| const throw ()
Returns a C-style character string describing the general cause of the current error (the same string passed to the ctor).
Reimplemented from std::exception.