std::money_put::~money_put

From cppreference.com
< cpp‎ | locale‎ | money put
Defined in header <locale>
protected: ~money_put();

Destructs a std::money_put facet. This destructor is protected and virtual (due to base class destructor being virtual). An object of type std::money_put, 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::money_put and implements a public destructor.

[edit] Example

#include <iostream>
#include <locale>
struct Destructible_money_put : public std::money_put<wchar_t>
{
    Destructible_money_put(std::size_t refs = 0) : money_put(refs) {}
    ~Destructible_money_put() {}; // public dtor
};
int main()
{
    Destructible_money_put dc;
    // std::money_put<wchar_t> c;  // compile error: protected destructor
}