函数指针

#include <iostream>using namespace std;double f (double n);double fun (double(*funptr)(double), double a, double b);int main (){    double sum;    sum = fun(f, 0.0, 1.0);    cout << sum << endl;    return 0;}double fun (double(*funptr)(double), double a, double b){    double result;    result = (b-a)/2*((*funptr)(a)+(*funptr)(b));    return result;}double f (double n){    return n*n;}