C++编程范式(函数)

 1 //
 2 //  main.cpp
 3 //  test
 4 //
 5 //  Created by Shaojun on 30/5/2020.
 6 //  Copyright © 2020 Shaojun. All rights reserved.
 7 //
 8 
 9 #include <iostream>
10 #include <stdio.h>
11 using namespace std;
12 
13 
14 int add1(int a, int b)
15 {
16     return (a + b);
17 }
18 
19 class ADD
20 {
21 private:
22     int x,y;
23 public:
24     ADD()
25     {
26         
27     }
28     int operator()(int x, int y)
29     {
30         return (x + y);
31     }
32     
33 };
34 
35 
36 template<typename T, typename U>
37 auto add3(T a, U b) -> decltype(a + b)
38 {
39     return a + b;
40 }
41 
42 auto add4 = [](int a, int b) -> int
43 {
44     return a + b;
45 };
46 
47 
48 int main(int argc, const char * argv[]) {
49     ADD add2;
50     std::cout << add1(3, 4) << std::endl;
51     std::cout << add2(3, 4) << std::endl;
52     std::cout << add3(3, 4) << std::endl;
53     std::cout << add4(3, 4) << std::endl;
54     return 0;
55 }