C-Style Strings as template arguments?

Can C-Style strings be used as template arguments?

I tried:

template <char *str>
struct X
{
    const char *GetString() const
    {
         return str;
    }
};

int main()
{
    X<"String"> x;
    cout<<x.GetString();
}

And although I get no complaints about the class definition, the instantiation yields 'X' : invalid expression as a template argument for 'str' (VC).