C++类模板

#include <iostream>
#include <cstdlib>
using namespace std;

typedef struct Tstudent      //结构体完整定义
{
    int nId;
    float fGpa;

}Tstudent;

template <class T>           //模版类
class CStroe
{
public:
    CStroe();            //构造函数
    T &getElem();        // 返回引用
    void putElem(const T &x);       //传递类型引用

private:
    T item;                          //数据
    bool haveValue;                 //控制

};
template<class T> CStroe<T>::CStroe():haveValue(false){}//构造函数初始化

template<class T> T& CStroe<T>::getElem()  // 返回引用
{
    ////控制开关状态
    if(!haveValue)             
    {
        cout<<"No item present!"<<endl;
        //exit(1);
    }
    return item;
}
template<class T> void CStroe<T>::putElem(const T &TRec)            //引用(别名)传递
{
    haveValue=true;                      //设置开关状态
    item =TRec;                             //
}



int main()
{
    //整形例
    CStroe<int> nStu1,nStu2;        //模版类
    nStu1.putElem(3);
    nStu2.putElem(-7);
    cout<<nStu1.getElem()<<""<<nStu2.getElem()<<endl;

    //结构类型例
    Tstudent tG={1000,23};         //结构体

    CStroe<Tstudent> tS3;          //模版类
    tS3.putElem(tG);
    cout<<"The student ID is "<<tS3.getElem().nId<<"\t"<<"Gpa is"<<tS3.getElem().fGpa<< endl;

    //Double类型
    CStroe<double> dStu;
    cout<<"Retrieving object d...";
    cout<<dStu.getElem()<<endl;


    getchar();
    return 0;

}