模板類的友員函數

#include<iostream>

using namespace std;

template<class T>

class Complex{

public:

Complex(T a, T b);

void setComplex(T a,T b);

friend Complex<T> operator+(const Complex<T> &c1, const Complex<T> &c2){

//對于模板類的友員函數一定要寫在類內！！！不可以再類外實現

T p_w_picpath = c1.p_w_picpath + c2.p_w_picpath;

T real = c1.real + c2.real;

return Complex<T>(real,p_w_picpath);

//這個必須按照這樣寫，不能加個對象！因為類型不確定！

}

friend Complex<T>operator-(const Complex<T> &c1, const Complex<T> &c2){

T p_w_picpath = c1.p_w_picpath - c2.p_w_picpath;

T real = c1.real - c2.real;

return Complex<T>(real,p_w_picpath);

}

friend Complex<T> operator-(const Complex &c1){

return Complex<T> (-c1.real, -c1.p_w_picpath);

}

void print()const;

private:

T real, p_w_picpath;

};

template <class T>

Complex<T>::Complex(T a, T b){

setComplex(a, b);

}

template<class T>

void Complex<T>::print()const{

cout << "real=" << real << "p_w_picpath=" << p_w_picpath << endl;

}

template <class T>

void Complex<T>::setComplex(T a, T b){

real = a;

p_w_picpath = b;

}

int main(){

Complex<int> a(2, 3);

Complex<int> b(2, 4);

(a + b).print();

(a - b).print();

(-a).print();

system("pause");

return 0;

}