c++ primer plus 第八章《编程题8.7.4》

/*My lady first.10.5212   20.3333   30.2256   0My lady first.10.5212   20.3333   30.2256   6466.18*/#include <iostream>using namespace std;struct box {    char maker[40];    float height;    float width;    float length;    float volume;};void show(const box &book);void vol(box &book);int main() {    //cout.precision(8);    //cout.setf(ios::fixed, ios::floatfield);    box book = {"My lady first.", 10.5212, 20.3333, 30.2256};    show(book);    vol(book);    show(book);    return 0;}void show(const box &book) {    cout << book.maker << "\n";    cout << book.height << "   " << book.width << "   " << book.length << "   " << book.volume << "\n";}void vol(box &book) {    book.volume = book.height * book.width * book.length;}