CODEWITHSUNDEEP
c++reference
user1721757
user1721757

Reputation: 89

reference to address of stack object

I am having difficulty understanding why below code does not compile under Visual Studio 2012, error already embedded in below code. I feel it has something to do with referencing stack object, but not quite sure. Can someone help?

Thanks

#include <iostream>

typedef struct Node {
    Node *next;
} Node;

void test(Node *&p) {
    p=p->next;
}

void main() {
    Node *p1=new Node();
    test(p1);   // this line compiles okay

    Node p={0};
    test(&p);    // error C2664: 'test' : cannot convert parameter 1 from 'Node *' to 'Node *&'
}

Upvotes: 0

Views: 91

Answers (2)

maditya
maditya

Reputation: 8886

You're passing a variable by address, not a pointer to a variable by reference. I think this will work:

void main() {
    Node *p1=new Node();
    test(p1);   

    Node p={0};
    Node* p2 = &p;
    test(p2);     
}

Upvotes: 1

Alexey Frunze
Alexey Frunze

Reputation: 62048

&p is not a variable of type Node*. It's a constant of type Node*.

Even if you could somehow take a reference to p and pass it to test(), p=p->next; would still fail because you can't assign to a constant.

Upvotes: 2

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