const // It is a const object...class nullptr_t

我正在尝试使用 Visual Studio 2008 Express 编译源代码，但出现此错误：

const // It is a const object...
class nullptr_t 
{
  public:
    template<class T>
    inline operator T*() const // convertible to any type of null non-member pointer...
    { return 0; }
    template<class C, class T>
    inline operator T C::*() const   // or any type of null member pointer...
    { return 0; }
  private:
    void operator&() const;  // Can't take address of nullptr
} nullptr = {};

#if _MSC_VER < 1600 //MSVC version <8
     #include "nullptr_emulation.h"
#endif