error: unused implementer of `Critical` that must be used
  --> $DIR/must_use-trait.rs:33:5
   |
LL |     get_critical();
   |     ^^^^^^^^^^^^^^
   |
note: the lint level is defined here
  --> $DIR/must_use-trait.rs:1:9
   |
LL | #![deny(unused_must_use)]
   |         ^^^^^^^^^^^^^^^

error: unused boxed `Critical` trait object that must be used
  --> $DIR/must_use-trait.rs:34:5
   |
LL |     get_boxed_critical();
   |     ^^^^^^^^^^^^^^^^^^^^

error: unused boxed boxed `Critical` trait object that must be used
  --> $DIR/must_use-trait.rs:35:5
   |
LL |     get_nested_boxed_critical();
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: unused boxed `Critical` trait object in tuple element 1 that must be used
  --> $DIR/must_use-trait.rs:37:5
   |
LL |     get_critical_tuple();
   |     ^^^^^^^^^^^^^^^^^^^^

error: unused implementer of `Critical` in tuple element 2 that must be used
  --> $DIR/must_use-trait.rs:37:5
   |
LL |     get_critical_tuple();
   |     ^^^^^^^^^^^^^^^^^^^^

error: aborting due to 5 previous errors