c++STL之內建函数对象

#include<iostream>
using namespace std;
#include <functional> //内建函数对象头文件

//内建函数对象  算术仿函数

//negate 一元仿函数  取反仿函数
void test01()
{
    negate<int>n;

    cout << n(50) << endl;
}

//plus  二元仿函数   加法
void test02()
{
    plus<int>p;

    cout << p(10, 20) << endl;
}

int main() {

    test01();

    test02();

    system("pause");

    return 0;
}

#include<iostream>
using namespace std;
#include <vector>
#include <algorithm>
#include <functional>


//内建函数对象 _关系仿函数  
//大于 greater
class MyCompare 
{
public:
    bool operator()(int v1,int v2)
    {
        return v1 > v2;
    }
};

void test01()
{
    vector<int>v;

    v.push_back(10);
    v.push_back(30);
    v.push_back(40);
    v.push_back(20);
    v.push_back(50);

    for (vector<int>::iterator it = v.begin(); it != v.end(); it++)
    {
        cout << *it << " ";
    }
    cout << endl;

    //降序
    //sort(v.begin(), v.end(), MyCompare());
    //greater<int>() 内建函数对象
    sort(v.begin(), v.end(), greater<int>());
    for (vector<int>::iterator it = v.begin(); it != v.end(); it++)
    {
        cout << *it << " ";
    }
    cout << endl;

}

int main() {

    test01();

    system("pause");

    return 0;
}

#include<iostream>
using namespace std;
#include <vector>
#include <algorithm>
#include <functional>

//内建函数对象_逻辑仿函数
//逻辑非  logical_not

void test01()
{
    vector<bool>v;
    v.push_back(true);
    v.push_back(false);
    v.push_back(true);
    v.push_back(false);

    for (vector<bool>::iterator it = v.begin(); it != v.end(); it++)
    {
        cout << *it << " ";
    }
    cout << endl;

    //利用逻辑非  将容器v 搬运到 容器v2中,并执行取反操作
    vector<bool>v2;
    v2.resize(v.size());

    transform(v.begin(), v.end(), v2.begin(), logical_not<bool>());

    for (vector<bool>::iterator it = v2.begin(); it != v2.end(); it++)
    {
        cout << *it << " ";
    }
    cout << endl;

}


int main() {

    test01();

    system("pause");

    return 0;
}