std::exception::what (3) - Linux Manuals
std::exception::what: std::exception::what
NAME
std::exception::what - std::exception::what
Synopsis
virtual const char* what() const throw(); (until C++11)
virtual const char* what() const noexcept; (since C++11)
Returns the explanatory string.
Parameters
(none)
Return value
Pointer to a null-terminated string with explanatory information. 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 on the exception object is called.