运算符重载和对象引用

Question

I have some code which overloads the << operator to print out some data I used this website and pretty much copied the code

https://msdn.microsoft.com/en-us/library/1z2f6c2k.aspx

I can get the code to work properly but not for my given example.

As you can see by the link:

// overload_date.cpp
// compile with: /EHsc
#include <iostream>
using namespace std;

class Date
{
    int mo, da, yr;
public:
    Date(int m, int d, int y)
    {
        mo = m; da = d; yr = y;
    }
    friend ostream& operator<<(ostream& os, const Date& dt);
};

ostream& operator<<(ostream& os, const Date& dt)
{
    os << dt.mo << '/' << dt.da << '/' << dt.yr;
    return os;
}

int main()
{
    Date dt(5, 6, 92);
    cout << dt;
}

But for my example I create pointers to the objects rather than the values directly, so I'd have something like:

Item *it;
it = new Screwdriver("big", 11);
cout << it;

But this then only prints out the pointer! how do I dereference this? or is this even the best way to do it ?

Answer 1

使用*运算符解反指针，如下所示：

std::cout << *it;

Answer 2

See code below:

Item *it;
it = new Screwdriver("big", 11);
cout << *it;

C++ has dereference operator * to go from pointer to the value it points to.