error[E0308]: mismatched types
  --> $DIR/issue-112385-while-assign-lhs-place-expr-ice.rs:7:11
   |
LL |     while Some(foo) = None {}
   |           ^^^^^^^^^^^^^^^^ expected `bool`, found `()`
   |
help: consider adding `let`
   |
LL |     while let Some(foo) = None {}
   |           +++

error: aborting due to 1 previous error

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