c++ accumulate 计算自定义数据

大家主要看一下test02,假设一共10个人，用accumulate求一下平均年龄,该如何实现?
我觉得底层是+=操作,重载了+=号，好像没啥用

#include <iostream>
using namespace std;
#include<vector>
#include<algorithm>
#include<string>
#include<ctime>
#include<numeric>

class Person
{
public:
    Person()
    {

    }
    Person(string name, int age);
    ~Person();

    //int operator+=(int x)
    //{
    //    return this->m_Age += x;
    //}

    Person operator+=(Person tempt)
    {        
        this->m_Age+= tempt.m_Age ;
        return *this;
    }
private:
    string m_Name;
    int m_Age;

    friend void test02();
    friend class MyPrint;
};

Person::Person(string name, int age)
{
    this->m_Name = name;
    this->m_Age = age;
}

Person::~Person()
{

}

class MyPrint
{
public:
    void operator()(const Person& p)
    {
        cout << "濮撳悕" << p.m_Name << "骞撮緞" << p.m_Age << endl;
    }
};

void myPrint(int value)
{
    cout << value << " ";
}

void test01()
{
    vector<int>v;

    for (int i = 0; i < 101; i++)
    {
        v.push_back(i);
    }

    cout << "总数"<< endl;
    int sum = accumulate(v.begin(), v.end(), 1000);
    cout << sum << "\n";


}

void test02()
{

    vector<Person>v;
    char nameSeed[8][2] = { "A","B","C","D","E", "F", "G", "H" };
    srand((unsigned int)time(NULL));

    for (int i = 0; i < 8; i++)
    {
        int age = rand() % 100 + 1;
        v.push_back(Person((const char*)nameSeed[i], age));
    }



    Person pp("C", 0);
    Person ppp("D", 9999);
    v.push_back(pp);
    v.push_back(ppp);


    cout << "人员如下 :"<< endl;
    for_each(v.begin(), v.end(), MyPrint()); cout << endl;

    //int average = accumulate(v.begin(), v.end(), 0) / v.size();


}
int main()
{
    test01(); cout << endl;
    test02(); cout << endl;
    std::cout << "Hello World!\n";
}

先看截图：

修改如下：

 
 
#include <iostream>
#include<vector>
#include<algorithm>
#include<cstring>
#include<ctime>
#include<numeric>
using namespace std;

 
class Person
{
public:
    Person()
    {
 
    }
    Person(string name, int age);
    ~Person();
 
    Person operator+(Person tempt)  // 修改
    {        
        Person result;
        result.m_Name = this->m_Name;
        result.m_Age = this->m_Age + tempt.m_Age;
        return result;
    }

    int getAge() {  // 新增
        return m_Age;
    }

private:
    string m_Name;
    int m_Age;
 
    friend void test02();
    friend class MyPrint;
};
 
Person::Person(string name, int age)
{
    this->m_Name = name;
    this->m_Age = age;
}
 
Person::~Person()
{
 
}
 
class MyPrint
{
public:
    void operator()(const Person& p)
    {
        cout << "姓名：" << p.m_Name << "年龄：" << p.m_Age << endl;
    }
};
 
void myPrint(int value)
{
    cout << value << " ";
}
 
void test01()
{
    vector<int>v;
 
    for (int i = 0; i < 101; i++)
    {
        v.push_back(i);
    }
 
    cout << "总数"<< endl;
    int sum = accumulate(v.begin(), v.end(), 0);
    cout << sum << "\n";
 
 
}
 
void test02()
{
 
    vector<Person>v;
    char nameSeed[8][2] = { "A","B","C","D","E", "F", "G", "H" };
    srand((unsigned int)time(NULL));
 
    for (int i = 0; i < 8; i++)
    {
        int age = rand() % 100 + 1;
        v.push_back(Person((const char*)nameSeed[i], age));
    }
 
 
 
    Person pp("C", 0);
    Person ppp("D", 9999);
    v.push_back(pp);
    v.push_back(ppp);
 
 
    cout << "人员如下 :"<< endl;
    for_each(v.begin(), v.end(), MyPrint()); cout << endl;
 
    Person result = accumulate(v.begin(), v.end(), Person("", 0)); // 修改
    int average = result.getAge() / v.size(); //修改
    cout<< average<<endl;   
 
}
int main()
{
    test01(); cout << endl;
    test02(); cout << endl;
    std::cout << "Hello World!\n";
}
 

这个是 accumulate 的源码，你需要写一个 谓语 lambda