查找vector容器中指定数据

#include<iostream>
using namespace std;
#include<vector>
#include<string>
#include<algorithm>
class Person
{
public:
	Person(string name, int  age)
	{
		this->m_name = name;
		this->m_age = age;
	}
	string m_name;
	int m_age;
};
class Great20
{
public:
	bool operator()(Person& p)
	{
		return p.m_age = 20;
	}
};
class Great3
{
public:
	bool operator()(int& val) //这里传入的数据必须要应用不然就报错；
	{
		return val = 3;
	}
};
void test()
{
	vector<Person>v;
	Person p1("aaa", 10);
	Person p2("bbb", 20);
	Person p3("ccc", 30);
	Person p4("ddd", 40);

	v.push_back(p1);
	v.push_back(p2);
	v.push_back(p3);
	v.push_back(p4);
	vector<Person>::iterator it = find_if(v.begin(), v.end(), Great20()); //第三个参数是谓词；
	cout << "name is : " << it->m_name << "   are is: " << it->m_age << endl;
	vector<int> v1;
	v1.push_back(1);
	v1.push_back(2);
	v1.push_back(3);
	v1.push_back(4);
	vector<int>::iterator dit = find_if(v1.begin(), v1.end(), Great3());
	cout << *dit << endl;
}
int main()
{
	test();
}