basememberpair.hpp

C++ Templates 完全导引范例

/* The following code example is taken from the book
 * "C++ Templates - The Complete Guide"
 * by David Vandevoorde and Nicolai M. Josuttis, Addison-Wesley, 2002
 *
 * (C) Copyright David Vandevoorde and Nicolai M. Josuttis 2002.
 * Permission to copy, use, modify, sell and distribute this software
 * is granted provided this copyright notice appears in all copies.
 * This software is provided "as is" without express or implied
 * warranty, and with no claim as to its suitability for any purpose.
 */
#ifndef BASE_MEMBER_PAIR_HPP
#define BASE_MEMBER_PAIR_HPP

template <typename Base, typename Member>
class BaseMemberPair : private Base {
  private:
    Member member;
  public:
    // constructor
    BaseMemberPair (Base const & b, Member const & m)
     : Base(b), member(m) {
    }

    // access base class data via first()
    Base const& first() const {
        return (Base const&)*this;
    }
    Base& first() {
        return (Base&)*this;
    }

    // access member data via second()
    Member const& second() const {
        return this->member;
    }
    Member& second() {
        return this->member;
    }
};

#endif // BASE_MEMBER_PAIR_HPP