A definition for a static data member may be provided in a namespace scope enclosing the definition of the static member's class template. [ Example:
template<class T> class X { static T s; }; template<class T> T X<T>::s = 0;
— end example ]
An explicit specialization of a static data member declared as an array of unknown bound can have a different bound from its definition, if any. [ Example:
template <class T> struct A { static int i[]; }; template <class T> int A<T>::i[4]; // 4 elements template <> int A<int>::i[] = { 1 }; // OK: 1 element
— end example ]