Setting immutable static data inside a struct in a module constructor?

[aliak via Digitalmars-d-learn]

Is it possible to initialize static immutable members of a struct 
like you could do for a global immutable one?

immutable string a;
struct Test {
  static immutable string b;
}
shared static this() {
  a = "foo";
  Test.b = "bar";
}

Error: cannot modify immutable expression b