c++ - std::functional

 1 #include <vector>
 2 #include <string>
 3 #include <iostream>
 4 #include <functional>
 5 
 6 using namespace std;
 7 
 8 std::function<int (int)> Functional;
 9 
10 
11 int testFunc(int i) {
12     return i;
13 }
14 
15 auto lambda = [](int i) -> int { return i; };
16 
17 class Functor {
18 public:
19     int operator()(int i) {
20         return i;
21     }
22 };
23 
24 class test{
25 public:
26     int foo(int i) { return i; }
27     static int staticFunc(int i) { return i; }
28 };
29 
30 int  main() {
31     Functional = testFunc;
32     std::cout << "普通函数：" << Functional(1) << std::endl;
33 
34     Functional = lambda;
35     std::cout << "lambda函数:" << Functional(2) << std::endl;
36 
37     Functor functor;
38     Functional = functor;
39     std::cout << "仿函数:" << Functional(3) << std::endl;
40 
41     test ctest;
42     Functional = test::staticFunc;
43     std::cout << "类静态函数:" << Functional(4) << std::endl;
44 
45     Functional = std::bind(&test::foo, ctest, std::placeholders::_1);
46     std::cout << "类成员函数:" << Functional(5) << std::endl;
47 
48     std::cin.get();
49     return 0;
50 }