error[E0015]: calls in statics are limited to constant functions, tuple structs and tuple variants
  --> $DIR/issue-16538.rs:11:27
   |
LL | static foo: *const Y::X = Y::foo(Y::x as *const Y::X);
   |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^

error[E0277]: `*const usize` cannot be shared between threads safely
  --> $DIR/issue-16538.rs:11:1
   |
LL | static foo: *const Y::X = Y::foo(Y::x as *const Y::X);
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `*const usize` cannot be shared between threads safely
   |
   = help: the trait `Sync` is not implemented for `*const usize`
   = note: shared static variables must have a type that implements `Sync`

error[E0133]: use of extern static is unsafe and requires unsafe function or block
  --> $DIR/issue-16538.rs:11:34
   |
LL | static foo: *const Y::X = Y::foo(Y::x as *const Y::X);
   |                                  ^^^^ use of extern static
   |
   = note: extern statics are not controlled by the Rust type system: invalid data, aliasing violations or data races will cause undefined behavior

error: aborting due to 3 previous errors

Some errors have detailed explanations: E0015, E0133, E0277.
For more information about an error, try `rustc --explain E0015`.