template specialization and static members initialization

Lets say there is a templated class:

template<typename T>
class Storage
{
public:
    static std::map<T, std::vector<std::string> > things;
};

And now I want to specialize it for type int and initialize things.

The way that does not throw compile errors I found so far is this:

template<>
std::map<int, std::vector<std::string> > Storage<int>::things = {
    { 1, {"FOO", "foo"} },
    { 2, {"BAR", "bar"} },
    { 3, {"ZAR", "zar"} }
};

But how it turns out that we can specialize the class and initialize the static member at the same time ?