error[E0308]: mismatched types
  --> $DIR/issue-5216.rs:13:21
   |
LL | pub static C: S = S(f); //~ ERROR mismatched types
   |                     ^ expected struct `std::boxed::Box`, found fn item
   |
   = note: expected type `std::boxed::Box<(dyn std::ops::FnMut() + 'static)>`
              found type `fn() {f}`

error[E0308]: mismatched types
  --> $DIR/issue-5216.rs:18:19
   |
LL | pub static D: T = g; //~ ERROR mismatched types
   |                   ^ expected struct `std::boxed::Box`, found fn item
   |
   = note: expected type `std::boxed::Box<(dyn std::ops::FnMut() + 'static)>`
              found type `fn() {g}`

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0308`.