std::ctype<char>::~ctype (3) - Linux Man Pages
Defined in header <locale>
Destructs a std::ctype<char> facet. This destructor is protected and virtual (due to base_class destructor being virtual). An object of type std::ctype<char>, like most facets, can only be destroyed when the last std::locale object that implements this facet goes out of scope or if a user-defined class is derived from std::ctype<char> and implements a public destructor.
If, when this instance of std::ctype<char> was constructed, a custom classification table was provided and the second argument to the constructor (the boolean del) was true, then this destructor executes delete table().