Is there any other possiblitly to prove this point other than using 'extern' keyword :n3290 draft

Question

A point from ISO draft N3290 : Unqualified Name Lookup :section 3.4.1, para 14:

If a variable member of a namespace is defined outside of the scope of its namespace then any name that appears in the definition of the member (after the declarator-id) is looked up as if the definition of the member occurred in its namespace.

ex:

namespace N {
   int i = 4;
   extern int j;
}
int i = 2;
int N::j = i;       // N::j == 4

Is there any other possiblitly to prove this point other than using 'extern' keyword

can u give some other examples ... other than extern

Answer 1

Another example which doesn't use extern keyword:

//demo.cpp

int i = 100;
namespace N
{
    int i = 200;
    struct A
    {
        static int m;
    };
}

int N::A::m = i; //i is 100 or 200?

int main()
{
   cout << N::A::m << endl; //what will it print?
}

Output:

200

Online demo : http://www.ideone.com/pRVAb