19 Diagnostics library [diagnostics]

19.2 Exception classes [std.exceptions]

19.2.10 Class underflow_­error [underflow.error]

namespace std {
  class underflow_error : public runtime_error {
  public:
    explicit underflow_error(const string& what_arg);
    explicit underflow_error(const char* what_arg);
  };
}
The class underflow_­error defines the type of objects thrown as exceptions to report an arithmetic underflow error.
underflow_error(const string& what_arg);
Ensures: strcmp(what(), what_­arg.c_­str()) == 0.
underflow_error(const char* what_arg);
Ensures: strcmp(what(), what_­arg) == 0.