rust-clippy/tests/ui/unit_cmp.stderr

error: ==-comparison of unit values detected. This will always be true
  --> $DIR/unit_cmp.rs:16:8
   |
16 |     if { true; } == { false; } {
   |        ^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: `-D unit-cmp` implied by `-D warnings`

error: >-comparison of unit values detected. This will always be false
  --> $DIR/unit_cmp.rs:19:8
   |
19 |     if { true; } > { false; } {
   |        ^^^^^^^^^^^^^^^^^^^^^^