在友元关系一节中，在main函数中调用出错。帮忙看看～

ck329054222

1. #include<iostream>
   
2. 
   
3. class Lovers//lovers基类
   
4. {
   
5. public:
   
6. Lovers(std::string theName)
   
7. {
   
8. name = theName;//对参数name进行初始化
   
9. }
   
10. void kiss(Lovers * lover)
    
11. {
    
12. std::cout<<&name<<"我们家的"<<&lover->name<<std::endl;
    
13. }
    
14. ;
    
15. void ask(Lovers * lover,std::string something)
    
16. {
    
17. std::cout<<&lover->name<<"帮我"<<&something<<std::endl;
    
18. }
    
19. protected:
    
20. std::string name;//可以在子类中访问，但是不能在main中调用
    
21. 
    
22. friend class Others;
    
23. };
    
24. 
    
25. class Boyfriend:public Lovers//lovers子类Boyfriend
    
26. {
    
27. public:
    
28. Boyfriend(std::string theName);
    
29. };
    
30. 
    
31. class Girlfriend:public Lovers//lovers子类Girlfriend
    
32. {
    
33. public:
    
34. Girlfriend(std::string theName);
    
35. };
    
36. 
    
37. class Others//others基类
    
38. {
    
39. public:
    
40. Others(std::string theName)
    
41. {
    
42. name = theName;
    
43. }
    
44. void kiss(Lovers * lover)
    
45. {
    
46. std::cout<<&name<<"kiss"<<&lover->name<<std::endl;
    
47. }
    
48. protected:
    
49. std::string name;
    
50. };
    
51. 
    
52. int main()
    
53. {
    
54. Boyfriend boy("A哥");
    
55. Girlfriend girl("B妹");
    
56. 
    
57. Others other("路人");
    
58. 
    
59. girl.kiss(&boy);
    
60. girl.ask(&boy,"洗衣服");
    
61. 
    
62. std::cout<<"\n万恶的路人\n"<<std::endl;
    
63. 
    
64. other.kiss(&girl);
    
65. 
    
66. return 0;
    
67. }

复制代码

error LNK2019: 无法解析的外部符号 "public: __thiscall Boyfriend::Boyfriend(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >)" (??0Boyfriend@@QAE@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@Z)，该符号在函数 _main 中被引用