类模板外部实现(类模板重载操作符和友元的使用 笔记)

类模板外部实现

 

#define _CRT_SECURE_NO_WARNINGS #include<iostream> using namespace std; template<class T> class Person { //重载左移操作符 template<class T>//一定要加 在linux 不能通过 要在Linux下编译通过 需要friend ostream& operator<<<T>(ostream& os, Person<T>& p); friend ostream& operator<<(ostream& os, Person<T>& p); public: Person(T age ,T id); void show(); public: T age; T id; private: }; template<class T> Person<T>::Person(T age, T id) { this->age = age; this->id = id; } template<class T> void Person<T>::show() { cout << "Age:" << age <<endl<< "Id:" << id << endl; } template<class T> ostream& operator<<(ostream& os, Person<T>& p) { os << "Age:" << p.age << endl << "Id:" << p.id << endl; return os; } int main() { Person<int> p(10, 20); //p.show(); cout << p; system("pause");