Sams Teach Yourself C++ in 21 Days

Advanced Inheritance 565

16

93: {}

94:

95: PartNode::~PartNode()

96: {

97: delete itsPart;

98: itsPart = 0;

99: delete itsNext;

100: itsNext = 0;

101: }

102:

103: // Returns NULL if no next PartNode

104: PartNode * PartNode::GetNext() const

105: {

106: return itsNext;

107: }

108:

109: Part * PartNode::GetPart() const

110: {

111: if (itsPart)

112: return itsPart;

113: else

114: return NULL; //error

115: }

116:

117:

118:

119: // **************** Part List ************

120: class PartsList

121: {

122: public:

123: PartsList();

124: ~PartsList();

125: // needs copy constructor and operator equals!

126: void Iterate(void (Part::*f)()const) const;

127: Part* Find(int & position, int PartNumber) const;

128: Part* GetFirst() const;

129: void Insert(Part *);

130: Part* operator[](int) const;

131: int GetCount() const { return itsCount; }

132: static PartsList& GetGlobalPartsList()

133: {

134: return GlobalPartsList;

135: }

136: private:

137: PartNode * pHead;

138: int itsCount;

139: static PartsList GlobalPartsList;

140: };

141:

142: PartsList PartsList::GlobalPartsList;

143:

144:

LISTING16.6 continued