C++: friend as main in class

Question

Can main function become friend function in C++ ?

 #include "stdafx.h"
#include <iostream>
using namespace std;
class A {
public:
    A():i(10){}
private:
    int i;
    friend int main();
};

int main()
{
    A obj;
    cout<<obj.i;
    return 0;
}

Answer 1

3.6.1 of the Standard (wording from draft n3936, but it's the same in C++03) says that:

The function main shall not be used within a program.

The exact meaning of this rule isn't clear. The Standard formally defines semantics for the related term odr-used, but not simply used.

To be safe, assume that this rule means that "The function main shall not be named in a friend declaration."

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Interestingly, although the wording of this rule is identical to C++03, in that version what we now know as odr-used hadn't yet been renamed, and this rule was clearly referring to that concept. I wonder whether this was overlooked during the rename from used to odr-used. If the new term was intentionally not used here, the rationale for that decision might illuminate what uses, exactly, are intended to be forbidden.

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Shafik found that the rename took place in N3214, and this rule was intentionally not changed to odr-use, although it doesn't explain why.