error: unused logical operation that must be used
  --> $DIR/issue-85913.rs:4:5
   |
LL |     function() && return 1;
   |     ^^^^^^^^^^^^^^^^^^^^^^ the logical operation produces a value
   |
note: the lint level is defined here
  --> $DIR/issue-85913.rs:1:9
   |
LL | #![deny(unused_must_use)]
   |         ^^^^^^^^^^^^^^^
help: use `let _ = ...` to ignore the resulting value
   |
LL |     let _ = function() && return 1;
   |     +++++++

error: aborting due to 1 previous error