#include<iostream>
#include<algorithm>
#include<functional>
using namespace std;
int Max(int a, int b)
{
  return a > b ? a : b;
}
int main()
{
  //std :: placeholders ::_ 1 占位符
  auto p = bind(Max, std::placeholders::_1, 122);
  cout << p(1) << endl;  //第二个参数固定，只需要传第一个参数就行

#include<iostream>
#include<functional>
#include<string>
#include<algorithm>
using namespace std;
class Test
{
public:
  void printDate(int a, int b, int c)
  {
    cout << a + b + c << endl;
  }
};
int main()
{
  //绑定类中成员函数指针
  Test test;
  auto fun = bind(&Test ::printDate, &test, std::placeholders::_1, std::placeholders::_2, std::placeholders::_3);
  fun(1, 2, 3);
  //成员函数指针的使用
  //方法一:用auto推断
  auto fun1 = &Test::printDate;
  (test.*fun1)(1, 2, 3);
  //方法二:直接写
  void(Test :: * p1)(int a, int b, int c);
  p1 = &Test::printDate;
  (test.*p1)(1, 2, 8);
  void(Test:: * p2)(int a, int b, int c) = &Test::printDate;
  (test.*p2)(2, 4, 9);
  system("pause");
  return 0;
}

#include<iostream>
#include<functional>
#include<algorithm>
#include<vector>
using namespace std;
int main()
{
  vector<int> date = { 46, 89, 17, 89, 90 };
  auto fun = count_if(date.begin(), date.end(), bind(less<int>(), std::placeholders::_1, 60));
  cout << "小于60的人数" << fun << endl;
  system("pause");
  return 0;
}

include<iostream>
#include<functional>
#include<algorithm>
using namespace std;
void Date(int a, string b, double c)
{
  cout << "函数适配器和包装器的结合" << endl;
}
int main()
{
  //正常包装
  function<void(int, string, double)> fun2;
  fun2(1, "2", 1.1);
  //正常适配 （一个参数固定的话，这里类型也要写2个）
  function<void(int, string)> fun1 = bind(Date, std::placeholders::_1, std::placeholders::_2, 1.11);
  fun1(1, "3");
  //可以改变参数的位置
  function<void(string, int)> fun3 = bind(Date, std::placeholders::_2, std::placeholders::_1, 1.11);
  fun3("2", 1);
  //这里改变了第一个参数和第二个参数的位置，同时第三个参数固定
  return 0;
  system("pause");
}