function

#include <iostream>
#include <vector>
#include <list>
#include <map>
#include <set>
#include <string>
#include <algorithm>
#include <functional>
#include <memory>
using namespace std;

//声明一个模板
typedef std::function<int(int)> Functional;

//normal function
int TestFunc(int a)
{
  return a;
}

//lambda expression
auto lambda = [](int a)->int{return a;};

//functor仿函数
class Functor
{
public:
  int operator() (int a)
  {
      return a;
  }
};

//类的成员函数和类的静态成员函数
class CTest
{
public:
  int Func(int a)
  {
      return a;
  }
  static int SFunc(int a)
  {
      return a;
  }
};

int main(int argc, char* argv[])
{
  //封装普通函数
  Functional obj = TestFunc;
  int res = obj(0);
  cout << "normal function : " << res << endl;

  //封装lambda表达式
  obj = lambda;
  res = obj(1);
  cout << "lambda expression : " << res << endl;

  //封装仿函数
  Functor functorObj;
  obj = functorObj;
  res = obj(2);
  cout << "functor : " << res << endl;

  //封装类的成员函数和static成员函数
  CTest t;
  obj = std::bind(&CTest::Func, &t, std::placeholders::_1);
  res = obj(3);
  cout << "member function : " << res << endl;
  obj = CTest::SFunc;
  res = obj(4);
  cout << "static member function : " << res << endl;
  return 0;
}

 2.绑定函数

 TestFun t;
 t.bindFun(std::bind(&QtTestBindAndFunction::AAA,this,99));
 t.test();

class TestFun
{
public:
    void test() { qDebug() << m_fun(); }
    void bindFun(const std::function<int()>& f) { m_fun = f; }

private:    
    std::function<int()> m_fun;   
};