求助！C++模板相关

sudayly

在写一个EventManager时，想用模板代替继承，出现了问题，求大虾看看~。看错误信息好像是，析构函数没有定义？

测试文件

1. #include "EventHandler.h"
   
2. #include "LogHandler.h"
   
3. 
   
4. int main(int argc, char *argv[])
   
5. {
   
6.   EventHandler<int> *handler = new LogHandler<int>();
   
7.   
   
8.   handler->Handle(5);
   
9.   
   
10.   return 0;
    
11. }
    

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EventHandler.h文件

1. 
   
2. #ifndef EVENT_HANDLER_H
   
3. #define EVENT_HANDLER_H
   
4. 
   
5. template <typename Event>
   
6. class EventHandler {
   
7. 
   
8. public:
   
9. 
   
10.   virtual void Handle(Event e) = 0;
    
11.   
    
12.   virtual ~EventHandler();
    
13. };
    
14. 
    
15. #endif
    

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LogHandler.h文件

1. 
   
2. #ifndef LOG_HANDER_H
   
3. #define LOG_HANDER_H
   
4. 
   
5. #include "EventHandler.h"
   
6. #include <iostream>
   
7. 
   
8. using std::cout;
   
9. using std::ostream;
   
10. 
    
11. template <typename Event>
    
12. class LogHandler: public EventHandler<Event> {
    
13. 
    
14.   ostream& os_;
    
15. 
    
16. public:
    
17. LogHandler(ostream& os = cout) : os_(os) {
    
18.   }
    
19.   
    
20.   void Handle(Event e) {
    
21.     os_ << e;
    
22.   }
    
23. 
    
24.   ~LogHandler() {
    
25.   }
    
26. };
    
27. 
    
28. #endif
    

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编译出错信息为链接错误

1. 
   
2. $ make test
   
3. g++     test.cc   -o test
   
4. C:/DOCUME~1/lyyang/LOCALS~1/Temp/ccj2D9RZ.o:test.cc:(.text$_ZN10LogHandlerIiED0Ev[LogHandler<int>::~LogHandler()]+0x17): undefined reference to `EventHandler<int>::~EventHandler()'
   
5. C:/DOCUME~1/lyyang/LOCALS~1/Temp/ccj2D9RZ.o:test.cc:(.text$_ZN10LogHandlerIiED1Ev[LogHandler<int>::~LogHandler()]+0x17): undefined reference to `EventHandler<int>::~EventHandler()'
   
6. C:/DOCUME~1/lyyang/LOCALS~1/Temp/ccj2D9RZ.o:test.cc:(.rdata$_ZTV12EventHandlerIiE[vtable for EventHandler<int>]+0xc): undefined reference to `EventHandler<int>::~EventHandler()'
   
7. C:/DOCUME~1/lyyang/LOCALS~1/Temp/ccj2D9RZ.o:test.cc:(.rdata$_ZTV12EventHandlerIiE[vtable for EventHandler<int>]+0x10): undefined reference to `EventHandler<int>::~EventHandler()'
   
8. collect2: ld returned 1 exit status
   
9. make: *** [test] Error 1
   

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sonicling

virtual ~EventHandler();
=>
virtual ~EventHandler() {}

sudayly

回复 2# sonicling


    自从学校毕业后，就再没用过C++了，都忘完了。THANKS~