type A = for<'a: 'b,> fn(); // OK(rejected later by ast_validation)
type A = for<'a: 'b +> fn(); // OK (rejected later by ast_validation)
type A = for<'a, T> fn(); // OK (rejected later by ast_validation)
-type A = for<,> fn(); //~ ERROR expected one of `>`, `const`, identifier, or lifetime, found `,`
+type A = for<,> fn(); //~ ERROR expected one of `#`, `>`, `const`, identifier, or lifetime
fn main() {}