Re: How is common_type (N2615) supposed to work?

http://www.open-std.org/jtc1/sc22/WG21/docs/papers/2008/n2615.html#co...

I get this common_type traits
template <class ...T> struct common_type;

template <class T>
struct common_type<T>
{
     typedef T type;
};

template <class T, class U>
struct common_type<T, U>
{
private:
     static T&& t();
     static U&& u();
public:
     typedef decltype(true ? t() : u()) type;};

Using gcc 4.3.1, which is the only compiler I have that compiles
it, I tried this simple code:

typedef common_type<int>::type one;
typedef common_type<int, int>::type two;

The compiler seems to agree with me that 'one' is a typedef for
'int' while 'two' is a typedef for'int&&'. Why is that?