#include using namespace std;#include"vector"#include"algorithm"//void PrintV(vector &temp){ for (vector ::iterator it = temp.begin(); it != temp.end(); it++) { cout << *it << " "; } cout << endl;}void showV(int &n){ cout << n << " ";}class C_showV{public: void operator() (int &n) { cout << n << " "; }protected:private:};class C_showV2{public: C_showV2() { this->num = 0; } void operator() (int &n) { num++; cout << n << " "; } void PrintN() { cout << num << endl; }protected:private: int num;};int main(){ vector v1; v1.push_back(1); v1.push_back(6); v1.push_back(3); v1.push_back(18); cout << "PrintV(v1) +++++> "; PrintV(v1); cout << endl; cout << "运用回调函数入口实现：for_each(v1.begin(), v1.end(),showV )+++++> "; for_each(v1.begin(), v1.end(),showV ); cout << endl; cout << "运用函数对象入口实现：for_each(v1.begin(), v1.end(),C_showV())+++++> "; for_each(v1.begin(), v1.end(), C_showV()); cout << "\n我是漂亮的分割线，接下来针对于函数对象的几种情况：\n"; C_showV2 tem1 = for_each(v1.begin(), v1.end(), C_showV2()); cout << endl; tem1.PrintN();//4 C_showV2 tem2; C_showV2 tem11 = for_each(v1.begin(), v1.end(), tem2); // 初始化 cout << endl; tem11.PrintN(); //4 tem2.PrintN();// 0 tem2和tem1的值不相同的主要原因是实参和形参，在加上for_each的定义是元素 不是引用。 tem11 = for_each(v1.begin(), v1.end(), tem2);//赋值 cout << endl; tem11.PrintN();//4 system("pause");}