CODEWITHSUNDEEP
c++operator-overloading
Limon
Limon

Reputation: 993

C++ operator overloading for equality

I'm very new to C++ and trying to get up this simple example working, but for some reason I get unexpected results.

Code:

#include<iostream>

using namespace std;

struct node{
    string data;
    node *next;
    node *prev;

    node() {}

    bool operator==(const node &rhs) const {
        return data == rhs.data;
    }
};

int main(){
    bool loop=true;
    node* one = new node();
    one->data = "oddly specific";

    node* two = new node();
    two->data = "Something else";

    node* three = new node();
    three->data = "oddly specific";

    if (one == two)
        cout << "one == two";
    else
        cout << "one != two";
    if (one == three)
        cout << "one == three";
    else
        cout << "one != three";

    cout << endl;

    if(one->data == two->data)
        cout << "one == two";
    else
        cout << "one != two";
    if(one->data == three->data)
        cout << "one == three";
    else
        cout << "one != three";
}

I'm trying to create custom operator for ==

bool operator==(const node &rhs) const { return data == rhs.data; }

The second line prints what I expected to happen, it looks like the operator overloaded function is simply not run?

Upvotes: 0

Views: 2924

Answers (2)

Rog&#233;rio Ramos
Rog&#233;rio Ramos

Reputation: 286

When you do one == three you are actually comparing pointers rather than the objects themselves. Try: *one == *three.

Upvotes: 2

Rafal Mielniczuk
Rafal Mielniczuk

Reputation: 1342

You need to dereference the node structure, instead of comparing pointers:

if (*one == *two) {}

But as others pointed out, you should consider not using pointers, so just do:

node one;
node two;
....
if (one == two) {}

Upvotes: 5

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