std::ctype::~ctype
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                    | Defined in header  <locale> | ||
| protected: ~ctype(); | ||
Destructs a std::ctype facet. This destructor is protected and virtual (due to base class destructor being virtual). An object of type std::ctype, 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 and implements a public destructor.
[edit] Example
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#include <iostream> #include <locale> struct Destructible_ctype : public std::ctype<wchar_t> { Destructible_ctype(std::size_t refs = 0) : ctype(refs) {} ~Destructible_ctype() {}; // public dtor }; int main() { Destructible_ctype dc; // std::ctype<wchar_t> c; // compile error: protected destructor }