Question

我无法创建LO类的对象。代码如下。

Tem.h
   #ifndef TEM_H_
   #define TEM_H_

   #include <iostream>
   #include <exception>
   #include "UDPTest.h"

   template<class T>
   class Tem : public std::exception {
   public:
    T* UDPt;
    Tem( T& t) throw();
    virtual ~Tem() throw();
   };

   template<class T>
   class LO :public Tem<T> {
    char* mez;
   public:
    LO() throw() ;
    char* what() const throw();
    virtual ~LO() throw();
   };

   template<class T>
   class AT :public Tem<T>{
    char* mez;
    public:
    AT() throw();
    char* what() const throw();
    virtual ~AT() throw();
    };
    #endif /* TEM_H_ */



Tem.cpp



#include "Tem.h"
#include <iostream>
using namespace std;


template<class T>
Tem<T>::Tem(T& t) throw() : exception(){
UDPt = t;
// TODO Auto-generated constructor stub
}
template<class T>
Tem<T>::~Tem() throw() {
// TODO Auto-generated destructor stub
}

template<class T>
LO<T>::LO()  throw() {
cout<<"LO constructor"<<endl;
}
template<class T>
LO<T>::~LO() throw(){
}
template<class T>
char* LO<T>::what() const throw(){
return "Lockout validation failed.";
 }

template<class T>
AT<T>::AT() throw(){
cout<<"AT validation failed."<<endl;
}
template<class T>
char* AT<T>::what() const throw(){
return "Active Task validation failed.";
}
template<class T>
AT<T>::~AT() throw(){
}





UDPTest.h


#ifndef UDPTEST_H_
#define UDPTEST_H_

class UDPTest {
public:
int udp;
int tcp;
UDPTest();
virtual ~UDPTest();

};

#endif /* UDPTEST_H_ */




templatetest.cpp

#include <iostream>
#include "Tem.h"
#include "UDPTest.h"
//#include <exception>
using namespace std;

int main() {
cout << "!!!Hello World!!!" << endl; // prints !!!Hello World!!!
try{
    throw LO<int>();
    //LO<int> loo;
}catch(exception& e){
    cout<<"got";
}
return 0;
}

在main函数中我正在创建LO类对象并抛出，LO类继承了Tem类，它是模板，在Tem类中我有一个UDPTest类的指针。

据我所知，我在某处犯了错误，但我无法知道。请帮帮我

由于

Answer 1

在C ++中使用类模板时，必须在头文件中使用声明显式定义这些类的成员，否则您将无法编译它。

（见Why can templates only be implemented in the header file?）

创建对象时未定义的引用

1 个答案: