求助，请大家看看我那里写错了，照书上写的，只是把Date类改成模板了

[猴头]

开始我把代码贴了一部分，不完整，现在修改了其中的一些错误重新发一遍，代码是在vs2008上编译的

#ifndef DATE_H
#define DATE_H

#include<iostream>
using namespace std;

template<class T>
class Date
{
	public:
		Date(T = 1,T= 1,T=1900);
		void print() const;
		~Date();
	private:
		T month;
		T day;
		T year;
		T checkDate(T) const;
};
#endif

#ifndef EMPLOYEE_H
#define EMPLOYEE_H

#include"Date.h"
template<class T>
class Employee
{
public:
	Employee(const char* const,  const char* const,  const Date<T>& , const Date<T>&  );
	void print() const;
	~Employee()
	{
		cout<<"Employee object destructor: "<<lastName<<", "<<firstName<<endl;
	}
private:
	char firstName[25];
	char lastName[25];
	const Date<T> birthDay;
	const Date<T> hireDate;
};

#endif

#include"Date.h"

template<class T>
Date<T>::Date(T mn, T dy, T yr)
{
	if(mn>0&&mn<=12)
		month=mn;
	else
	{
		month=1;
		cout<<"InValid month("<<mn<<")set to 1"<<endl;
	}
	year=yr;
	day=checkDate(dy);
	cout<<"date object constructor for date"<<endl;
	print();
	cout<<endl;
}

template<class T>
void Date<T>::print() const
{
	cout<<month<<'-'<<day<<'-'<<'year'<<endl;
}

template<class T>
Date<T>::~Date()
{
	cout<<"Date 的析构函数正在运行......"<<endl;
	print();
	cout<<"Date 的析构函数运行结束..end.."<<endl;
}

template<class T>
T  Date<T>::checkDate(T testday) const
{
	static const T daypermonth[13]=
	{0,31,28,31,30,31,30,31,31,30,31,30,31};

	if(testday>0&&testday<=daypermonth[month])
		return testday;

	if((2==month)&&(29==testday)&&((0==year%400)||(0==year%4)&&(0!=year%100)))
		return testday;

	cout<<"Invalid day ("<<testday<<")set to 1"<<endl;
	return 1;
}

#include"Employee.h"

#include<string>
//using std::strlen;
//using std::strncpy;

#include<iostream>
using namespace std;

#include"Date.h"

template<class T>
Employee<T>::Employee(const char* const first, const char* const last, const Date<T>& dateOfBirth, const Date<T>& dateOfHire)
                                  :birthDay(dateOfBirth), 
								   hireDate(dateOfHire)
{
	int length=strlen(first);
	length = (length<25?length:24);
	strncpy(firstName,first,length);
	firstName[length]='\0';

	length = strlen(last);
	length = (length<25?length:24);
	strncpy(lastname,last,length);
	firstName[length]='\0';

	cout<<"Employee object constructor:"<<firstName<<' '<<lastname<<endl;
}

template<class T>
void Employee<T>::print() const
{
	cout<<lastName<<", "<<firstName<<" Hired: ";
	hireDate.print();
	cout<<" Birthday: ";
	birthDay.print();
	cout<<endl<<endl;
}

/*template<class T>
Employee<T>::~Employee()
{
	cout<<"Employee object destructor: "<<lastName<<", "<<firstName<<endl;
}*/

#include<iostream>
using namespace std;

#include"Employee.h"

int main()
{
	Date<int>birth(7,24,1949);
	Date<int>hire(3,12,1988);
	Employee<int> manager("bob","blue",birth,hire);

	cout<<endl<<endl;
	manager.print();

	cout<<"\nTest Date constructor with invalid value : "<<endl;
	Date<int>lastDayOff(14,35,1994);
	cout<<endl;

	system("pause");
	return 0;
}

[猴头]

编译器提示的错误如下：
>main.obj : error LNK2019: 无法解析的外部符号 "public: __thiscall Date<int>::~Date<int>(void)" (??1?$Date@H@@QAE@XZ)，该符号在函数 _main 中被引用
1>main.obj : error LNK2019: 无法解析的外部符号 "public: void __thiscall Employee<int>::print(void)const " (?print@?$Employee@H@@QBEXXZ)，该符号在函数 _main 中被引用
1>main.obj : error LNK2019: 无法解析的外部符号 "public: __thiscall Employee<int>::Employee<int>(char const * const,char const * const,class Date<int> const &,class Date<int> const &)" (??0?$Employee@H@@QAE@QBD0ABV?$Date@H@@1@Z)，该符号在函数 _main 中被引用
1>main.obj : error LNK2019: 无法解析的外部符号 "public: __thiscall Date<int>::Date<int>(int,int,int)" (??0?$Date@H@@QAE@HHH@Z)，该符号在函数 _main 中被引用
1>.\Debug/Class_Include_Object.exe : fatal error LNK1120: 4 个无法解析的外部命令
1>生成日志保存在“file://i:\学习测试\Class_Include_Object\Debug\BuildLog.htm”
1>Class_Include_Object - 5 个错误，0 个警告

[mstlq]

http://www.cppblog.com/michaelgao/archive/2008/10/09/63571.html

[游牧小小诗人]

学习下，，还没用过模版呢。。。

[猴头]

我把文件放在一起试试

[luciferisnotsatan]

模板类的实现是放在头文件.h里的，不能放源文件.cpp里

[猴头]

我把代码全放到同一个CPP文件下还是出现问题这次出现的问题是：
c:\documents and settings\hyz\桌面\class_include_object_in_only_file\date.h(39) : error C2995: 'Date<T>::Date<T>' : template function has already been defined
c:\documents and settings\hyz\桌面\class_include_object_in_only_file\date.h(11) : see declaration of 'Date<T>::Date<T>'
c:\documents and settings\hyz\桌面\class_include_object_in_only_file\date.h(45) : error C2995: 'print' : template function has already been defined
c:\documents and settings\hyz\桌面\class_include_object_in_only_file\date.h(12) : see declaration of 'print'
c:\documents and settings\hyz\桌面\class_include_object_in_only_file\date.h(53) : error C2995: 'Date<T>::~Date<T>' : template function has already been defined
c:\documents and settings\hyz\桌面\class_include_object_in_only_file\date.h(13) : see declaration of 'Date<T>::~Date<T>'
c:\documents and settings\hyz\桌面\class_include_object_in_only_file\date.h(69) : error C2995: 'checkDate' : template function has already been defined
c:\documents and settings\hyz\桌面\class_include_object_in_only_file\date.h(18) : see declaration of 'checkDate'
Error executing cl.exe.

[Quote=引用 3 楼 mstlq 的回复:]
http://www.cppblog.com/michaelgao/archive/2008/10/09/63571.html
[/Quote]

[bdmh]

好像是方法被重复定义了

[hai040]

[Quote=引用 7 楼 yan_hyz 的回复:]
我把代码全放到同一个CPP文件下还是出现问题这次出现的问题是：
c:\documents and settings\hyz\桌面\class_include_object_in_only_file\date.h(39) : error C2995: 'Date<T>::Date<T>' : template function has already been defined
c:\docu……
[/Quote]
把#include "date.h"去掉

[zhengjiankang]

模板类的实现要全部写在头文件里
需要在编译期确定类型

Date类也用模板来写
不知道有什么意义 求楼下解释

[猴头]

谢谢 搞定了
[Quote=引用 9 楼 hai040 的回复:]
引用 7 楼 yan_hyz 的回复:
我把代码全放到同一个CPP文件下还是出现问题这次出现的问题是：
c:\documents and settings\hyz\桌面\class_include_object_in_only_file\date.h(39) : error C2995: 'Date<T>::Date<T>' : template function has already be……
[/Quote]

[AlwaysSLH]

模板类的实现放到头文件里，不要放在cpp文件里