C++ 0x in GCC

gistfile1.txt

(18:54) changlp@bsd6:~/tmp % cat rval.cpp
#include <iostream>
using namespace std;

void p(int &&x)
{
        cout << x << endl;
}

int main(int argc,char**argv)
{
        p(2);
        return 0;
}
(18:54) changlp@bsd6:~/tmp % g++46 -std=c++0x rval.cpp
(18:54) changlp@bsd6:~/tmp % ./a.out
2