tuples/duo6.hpp

The following code example is taken from the book
C++ Templates - The Complete Guide
by David Vandevoorde and Nicolai M. Josuttis, Addison-Wesley, 2002
© Copyright David Vandevoorde and Nicolai M. Josuttis 2002


// partial specialization for Duo<> with only one field
template <typename A>
struct Duo<A,void> {
  public:
    typedef A    T1;  // type of first field
    typedef void T2;  // type of second field
    enum { N = 1 };   // number of fields

  private:
    T1 value1;        // value of first field

  public:
    // constructors
    Duo() : value1() {
    }
    Duo (T1 const & a)
     : value1(a) {
    }

    // field access
    T1& v1() { 
        return value1;
    }
    T1 const& v1() const {
        return value1;
    }
    
    void v2() { 
    }
    void v2() const {
    }
    //...
};