struct myfuncobj01

{

　　bool operator(int v){} // 接受一个参数，并且返回值为 Bool 即一元谓词

}

bool compare01(int v); // 同样是叫做一元谓词

struct myfuncobj02

{

　　bool operator(int v1，int v2){} // 接受两个参数，返回值为 Bool 即二元谓词

}

bool compare02(int v1，int v2); // 同样是叫做二元谓词

#include <iostream>

#include <algorithm>

#include <functional>

#include <vector>

using namespace std;

struct MyPrint : public binary_function<int, int, void>

{

    void operator()(int v, int val) const

    {

        cout << "v = " << v << " val = " << val << endl;

        cout << "v + val = " << v + val << endl;

    }

};

// 仿函数适配器 bind1st bind2nd 绑定适配器

void test01()

{

    vector<int> v;

    for (int i = ; i < ; i++)

    {

        v.push_back(i);

    }

    int addNum = ;

    for_each(v.begin(), v.end(), bind2nd(MyPrint(), addNum));

    // 绑定适配器  将一个二元函数对象转变成一元函数对象

    // bind1st bind2nd区别？

    // bind1st，将addNum绑定为函数对象的第一个参数

    // bind2nd，将addNum绑定为函数对象的第二个参数

    cout << "----------------------" << endl;

}

struct MyPrint02

{

    void operator()(int v)

    {

        cout << v << " ";

    }

};

struct MyCompare : public binary_function<int, int, bool>

{

    bool operator()(int v1, int v2) const

    {

        return v1 > v2;

    }

};

struct MyGreater5 : public binary_function<int, int, bool>

{

    bool operator()(int v, int val) const

    {

        cout << "v = " << v << " val = " << val << endl;

        return v > val;

    }

};

// 仿函数适配器 not1 not2 取反适配器

void test02()

{

    vector<int> v;

    for (int i = ; i < ; i++)

    {

        v.push_back(i);

    }

    for_each(v.begin(), v.end(), MyPrint02());

    cout << endl;

    // 正常排序 从大到小

    sort(v.begin(), v.end(), MyCompare());

    for_each(v.begin(), v.end(), MyPrint02());

    cout << endl;

    // 取反之后从小到大

    sort(v.begin(), v.end(), not2(MyCompare()));

    for_each(v.begin(), v.end(), MyPrint02());

    cout << endl;

    // not1 not2

    // 如果对二元谓词取反，用not2

    // 如果对一元谓词取反，用not1

    vector<int>::iterator it = find_if(v.begin(), v.end(), not1(bind2nd(MyGreater5(), )));

    if (it == v.end())

    {

        cout << "没有找到！" << endl;

    }

    else

    {

        cout << *it << endl;

    }

    cout << "----------------------" << endl;

}

// 仿函数适配器 ptr_fun

void MyPrint03(int val, int val2)

{

    cout << "val = " << val << " val2 = " << val2 << endl;

    cout << "val + val2 = " << val + val2 << endl;

}

void test03()

{

    vector<int> v;

    for (int i = ; i < ; i++)

    {

        v.push_back(i);

    }

    // ptr_func把普通函数转成函数对象

    for_each(v.begin(), v.end(), bind2nd(ptr_fun(MyPrint03), ));

    cout << "--------------" << endl;

}

// 成员函数适配器 mem_fun mem_fun_ref

class Person

{

public:

    Person(int age, int id) : age(age), id(id){}

    void show()

    {

        cout << "age = " << age << " id = " << id << endl;

    }

public:

    int age;

    int id;

};

void test04()

{

    // 如果容器中存放的对象或者对象指针，我们for_each算法打印的时候，调用类自己提供的打印函数

    vector<Person> v;

    Person p1(, ), p2(, ), p3(, );

    v.push_back(p1);

    v.push_back(p2);

    v.push_back(p3);

    for_each(v.begin(), v.end(), mem_fun_ref(&Person::show));

    cout << "--------------" << endl;

    vector<Person*> v1;

    v1.push_back(&p1);

    v1.push_back(&p2);

    v1.push_back(&p3);

    for_each(v1.begin(), v1.end(), mem_fun(&Person::show));

    // mem_fun_ref mem_fun区别?

    // 如果存放的是对象指针 使用mem_fun

    // 如果使用的是对象 使用mem_fun_ref

}

int main()

{

    test01();

    test02();

    test03();

    test04();

    getchar();

    return ;

}