类模版之偏特化

//类模板（模板定义以关键字template开始，后接尖括号括住的模板形参表，形参前用class或者typename关键字修饰）template<class T1, typename T2>class Compare{public:    Compare(T1 x = 0, T2 y = 0)        :x(x), y(y)    {    }    bool isEqual()    {        if (x == y)            return true;        return false;    }    T1 getX();    void setX(T1 x);private:    T1 x;    T2 y;};//每一个在类模板外定义的函数都要带一个帽子template<class T1, typename T2>T1 Compare<T1, T2>::getX(){    return x;}//每一个在类模板外定义的函数都要带一个帽子template<class T1, class T2>void Compare<T1, T2>::setX(T1 x){    this->x = x;}//类模板偏特化template<class T1>class Compare<T1, const char *>{public:    Compare(T1*x = 0, const char *y = 0)        :x(x), y(y)    {    }    bool isEqual()    {        if (!strcmp(x, y))            return true;        return false;    }    const char* getX();    void setX(const char* x);private:    T1 *x;    const char *y;};//类模板偏特化template<class T2>class Compare<const char *, T2>{public:    Compare(const char *x = 0, T2 *y = 0)        :x(x), y(y)    {    }    bool isEqual()    {        if (!strcmp(x, y))            return true;        return false;    }    const char* getX();    void setX(const char* x);private:    const char *x;    T2 *y;};void main(){    //使用类模板时，必须为模板形参显示指定实参，此处为int,int型    Compare<int, int> com1(10, 20);    com1.setX(20);    cout << com1.isEqual() << endl;    Compare<string,string> com2("jack", "jack");    cout << com2.isEqual() << endl;    //偏特化调用歧义：多个部分专用化与模版参数列表匹配    Compare<const char*, const char*> com3("jack", "jack");    cout << com3.isEqual() << endl;}