error[E0308]: mismatched types
  --> tests/compile_fail/struct_by_val.rs:15:8
   |
15 | fn foo(_foo: Foo) {} // Fail
   |    --- ^^^^ expected `Foo`, found `&mut _`
   |    |
   |    arguments to this function are incorrect
   |
   = note:         expected struct `Foo`
           found mutable reference `&mut _`
note: function defined here
  --> tests/compile_fail/struct_by_val.rs:15:4
   |
15 | fn foo(_foo: Foo) {} // Fail
   |    ^^^ ---------