C++ 函数指针

函数指针就是一段函数的入口。就是一块汇编代码的起始地址，jmp xxx.
include “stdafx.h”
include “iostream”
using namespace std;
typedef int(*FP_CALC)(int, int);//定义一个函数指针类型 
int add(int a, int b) 
 { 
 return a + b; 
 }int sub(int a, int b) 
 { 
 return a - b; 
 }int mul(int a, int b) 
 { 
 return a * b; 
 }int div_2(int a, int b) 
 { 
 return b ? a / b : -1; 
 }int calc(FP_CALC pf, int a, int b) 
 { 
 return pf(a, b); 
 }int main(int argc, _TCHAR* argv[]) 
 { 
 cout << calc(add, 2, 5) << endl; 
 cout << calc(sub, 2, 5) << endl; 
 cout << calc(mul, 2, 5) << endl; 
 cout << calc(div_2, 2, 5) << endl; 
 return 0; 
 }