choices

1、定义。

  /**
   * \brief %Choice for performing commit
   *
   * Must be refined by inheritance such that the information stored
   * inside a choice is sufficient to redo a commit performed by a
   * particular brancher.
   *
   * \ingroup TaskActor
   */
  class GECODE_VTABLE_EXPORT Choice : public HeapAllocated {
    friend class Space;
  private:
    unsigned int bid; ///< Identity to match creating brancher
    unsigned int alt; ///< Number of alternatives

    /// Return id of the creating brancher
    unsigned int id(void) const;
  protected:
    /// Initialize for particular brancher \a b and alternatives \a a
    Choice(const Brancher& b, const unsigned int a);
  public:
    /// Return number of alternatives
    unsigned int alternatives(void) const;
    /// Destructor
    GECODE_KERNEL_EXPORT virtual ~Choice(void);
    /// Report size occupied by choice
    virtual size_t size(void) const = 0;
    /// Archive into \a e
    GECODE_KERNEL_EXPORT
    virtual void archive(Archive& e) const;
  };

2、实现。

  /*
   * Choices
   *
   */
  forceinline
  Choice::Choice(const Brancher& b, const unsigned int a)
    : bid(b.id()), alt(a) {}

  forceinline unsigned int
  Choice::alternatives(void) const {
    return alt;
  }

  forceinline unsigned int
  Choice::id(void) const {
    return bid;
  }

  forceinline
  Choice::~Choice(void) {}

来自为知笔记(Wiz)