14.2.7重学C++之【类模板的分文件编写】

person.h

#pragma once
#include<iostream>
#include<string>
using namespace std;


template<class T1, class T2>
class Person{
public:
    T1 name;
    T2 age;

    Person(T1 _name, T2 _age);

    void show();
};

person.cpp

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


template<class T1, class T2>
Person<T1, T2>::Person(T1 _name, T2 _age)
{
    this->name = _name;
    this->age = _age;
}


template<class T1, class T2>
void Person<T1, T2>::show()
{
    cout << "name:" << this->name << " age:" << this->age << endl;
}

person.hpp

#pragma once
#include<iostream>
#include<string>
using namespace std;


template<class T1, class T2>
class Person{
public:
    T1 name;
    T2 age;

    Person(T1 _name, T2 _age);

    void show();
};


template<class T1, class T2>
Person<T1, T2>::Person(T1 _name, T2 _age)
{
    this->name = _name;
    this->age = _age;
}


template<class T1, class T2>
void Person<T1, T2>::show()
{
    cout << "name:" << this->name << " age:" << this->age << endl;
}

main.cpp

#include<iostream>
#include<stdlib.h>
#include<string>
using namespace std;

// 解决方法1
//#include "person.h" // error
//#include "person.cpp" // ok

//解决方法2（常用）
#include "person.hpp"


/*
    1.3.7类模板的分文件编写
        目标：掌握类模板成员函数分文件编写产生的问题以及解决方式
        问题：类模板中成员函数创建时机是在调用阶段，导致分文件编写时链接不到
        解决方式1：直接包含.cpp源文件
        解决方式2：将声明和实现写到同一个文件中，并更改后缀名为.hpp，hpp是约定的名称，并不是强制（见到.hpp就知道是类模板的分文件编写）
*/


/*
template<class T1, class T2>
class Person{
public:
    T1 name;
    T2 age;

    Person(T1 _name, T2 _age);

    void show();
};
*/


/*
template<class T1, class T2>
Person<T1, T2>::Person(T1 _name, T2 _age)
{
    this->name = _name;
    this->age = _age;
}


template<class T1, class T2>
void Person<T1, T2>::show()
{
    cout << "name:" << this->name << " age:" << this->age << endl;
}
*/


void test(){
    Person<string, int> p("tom", 10);
    p.show();
}


int main(){
    test();

    system("pause");
    return 0;
}