Re: Hiding members using `using'

This is just an observation (of my own ignorance, really). I have many
times used a class-scope using declaration to `promote' the
accessibility of a member of a base class in a derived class, but I
hadn't ever applied it to do the opposite, i.e. hide a base class
member. Consequently, though I had no reason to suppose that it wasn't
possible, I did have to try it out (`engineer's solution' - no access to
the Standard at this moment) and found that it does work.

    #include<iostream>

    class A {
    private:
       int i_;
    public:
       A(int i) : i_(i) { }
       void seti(int i) { i_ = i; }
       int geti() const { return i_; }
    };

    class B : public A {
    public:
       B(int i) : A(i) { }
       void dbli() { seti(2 * geti()); }
    private:
       using A::seti; // hide
    };

    int main()
    {
       A a1(1);
       a1.seti(2);
       std::cout<< "a1.geti() = "<< a1.geti()<< '\n';
       B b1(3);
       // b1.seti(4); // inaccessible
       b1.dbli();
       std::cout<< "b1.geti() = "<< b1.geti()<< '\n';
    }

    /**
     * Output: // largely irrelevant
     * a1.geti() = 2
     * b1.geti() = 6
     */

So... Yay!