A definition for a static data member or static data member template may be
provided in a namespace scope enclosing the definition of the static member's
class template.
[Example 1: template<class T>class X {static T s;
};
template<class T> T X<T>::s =0;
struct limits {template<class T>staticconst T min; // declaration};
template<class T>const T limits::min ={}; // definition — end example]