static constexpr member of same type as class being defined

Question

I would like a class C to have a static constexpr member of type C. Is this possible in C++11?

Attempt 1:

struct Foo {
    constexpr Foo() {}
    sta         


        

Answer 1

An update on Richard Smith's answer, attempt 3 now compiles on both GCC 4.9 and 5.1, as well as clang 3.4.

struct Foo {
  std::size_t v;
  constexpr Foo() : v(){}
  static const Foo f;
};

constexpr const Foo Foo::f = Foo();

std::array a;

However, when Foo is a class template, clang 3.4 fails, but GCC 4.9 and 5.1 still work ok:

template < class T >
struct Foo {
  T v;
  constexpr Foo() : v(){}
  static const Foo f;
};

template < class T >
constexpr const Foo Foo::f = Foo();

std::array::f.v> a; // gcc ok, clang complains

Clang error :

error: non-type template argument is not a constant expression
std::array::f.v> a;
                ^~~~~~~~~~~~~~~~~~~~~