當C++遇到iOS應用開發之---List集合

在Object-C中，數組使用NSArray和NSMutableArray(可變長數組)。使用語法如下：

NSArray *array = [[NSArray alloc] initWithObjects:@"One",@"Two",@"Three",@"Four",nil];

取數組元素的方法:

[array objectAtIndex:2]);

因為數組在開發中會被頻繁使用，且objectAtIndex的寫法看著過於繁復，遠不如array[2]這種直觀。所以我將C++中的vector類進行了封裝，並增加一些新的功能：

1. #include <iostream>
2. #include <vector>
4. using namespace std;
5. using namespace std::tr1;
6. template<typename T, typename _Alloc = std::allocator<T> >
7. class List: public vector<T, _Alloc>
8. {
9. private:
10. typedef typename std::vector<T>::iterator list_it;
12. list_it _it;
14. public:
15. List(){}
17. List(NSArray *array){
18. copyFromArray(array);
19. }
22. List(string *array){
23. copyFromArray(array);
24. }
26. List(int *array){
27. copyFromArray(array);
28. }
30. ~List()
31. {
32. std::cout<<"list destroy!"<<endl;
33. }
35. List& add(const T t){
36. this->push_back(t);
37. return (*this);
38. }
40. void clear(){
41. //this->clear();
42. this->erase(this->begin(), this->end());
43. }
46. BOOL contains(const T t){
47. return indexOf(t) >= 0;
48. }
51. int indexOf(const T t){
52. list_it it = std::find(this->begin(),this->end() , t ) ;
53. if(it != this->end())
54. return it - this->begin();
55. return -1 ;
56. }
58. void insert(int index, const T t)
59. {
60. this->insert(this.begin() + index, 1, t);
61. }
64. void remove(const T t)
65. {
66. int pos = indexOf(t);
67. if (pos >= 0)
68. this->removeAt(pos);
69. }
71. void removeAt(int index)
72. {
73. if (this->size() > index){
74. this->erase(this->begin() + index, this->begin() + index + 1);
75. }
76. }
78. int count()
79. {
80. return this->size();
81. }
83. void copyFrom(List<T> list)
84. {
85. this->assign(list.begin(), list.end());
86. }
88. void copyFromArray(NSArray *array){
89. for(int i = 0; i< [array count]; i++){
90. T t = (T)[array objectAtIndex:i];
91. this->push_back(t);
92. }
93. }
95. void copyFromArray(string* array){
96. for(int i = 0; i< array->length(); i++){
97. T t = (T)array[i];
98. this->push_back(t);
99. }
100. }
102. void copyFromArray(int* array){
103. for(int i = 0; i<(sizeof(array)/sizeof(int)); i++){
104. T t = (T)array[i];
105. this->push_back(t);
106. //this->vector<T>::push_back(new T);//usage:用父類方法 或 static_cast<vector<T>*>(this)->push_back(T);
107. }
108. }
109. };