error: you might have meant to write `impl` instead of `fn`
  --> $DIR/issue-105366.rs:5:1
   |
LL | fn From<i32> for Foo {
   | ^^
   |
help: replace `fn` with `impl` here
   |
LL | impl From<i32> for Foo {
   | ~~~~

error: aborting due to previous error