86.运算符重载

 1 #define _CRT_SECURE_NO_WARNINGS
 2 #include <iostream>
 3 using namespace std;
 4 
 5 class mystring
 6 {
 7 public:
 8     char *pstr;
 9     int length;
10     mystring():pstr(nullptr),length(0)
11     {
12 
13     }
14 
15     mystring(char *str)
16     {
17         //获取字符串长度
18         this->length = strlen(str) + 1;
19         this->pstr = new char[this->length + 1];
20         //拷贝
21         strcpy(this->pstr, str);
22     }
23 
24     //拷贝构造
25     mystring(const mystring &my)
26     {
27         this->length = my.length;
28         this->pstr = new char[this->length];
29         strcpy(this->pstr, my.pstr);
30     }
31 
32     mystring add(const mystring &my)
33     {
34         int n = this->length + my.length - 1;
35         mystring temp;
36         temp.length = n;
37         //分配内存
38         temp.pstr = new char[temp.length];
39         strcpy(temp.pstr, this->pstr);
40         //尾部添加
41         strcat(temp.pstr, my.pstr);
42         return temp;
43     }
44 
45     //重载加法
46     mystring operator +(const mystring &my)
47     {
48         int n = this->length + my.length - 1;
49         mystring temp;
50         temp.length = n;
51         //分配内存
52         temp.pstr = new char[temp.length];
53         strcpy(temp.pstr, this->pstr);
54         //尾部添加
55         strcat(temp.pstr, my.pstr);
56         return temp;
57     }
58 };
59 
60 template<class T>
61 T add(T a, T b)
62 {
63     return a + b;
64 }
65 
66 void main()
67 {
68     mystring str1 = "hello";
69     mystring str2 = "world";
70     //mystring str3 = str1.add(str2);
71     //mystring str3 = str1 + str2;
72     mystring str3 = str1.operator+(str2);
73     cout << str3.pstr << endl;
74 
75     //模板与运算符重载
76     cout << add<mystring>(str1, str2).pstr << endl;
77     cin.get();
78 }