diff --git a/compiler/rustc_infer/src/infer/error_reporting/mod.rs b/compiler/rustc_infer/src/infer/error_reporting/mod.rs index 20864c657ffd7..529ddf03a8cc3 100644 --- a/compiler/rustc_infer/src/infer/error_reporting/mod.rs +++ b/compiler/rustc_infer/src/infer/error_reporting/mod.rs @@ -2078,7 +2078,8 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> { diag.span_suggestion( span, *msg, - format!("{}.as_ref()", snippet), + // HACK: fix issue# 100605, suggesting convert from &Option to Option<&T>, remove the extra `&` + format!("{}.as_ref()", snippet.trim_start_matches('&')), Applicability::MachineApplicable, ); } diff --git a/src/test/ui/issues/issue-100605.rs b/src/test/ui/issues/issue-100605.rs new file mode 100644 index 0000000000000..917a45c15bbc8 --- /dev/null +++ b/src/test/ui/issues/issue-100605.rs @@ -0,0 +1,9 @@ +fn takes_option(_arg: Option<&String>) {} + +fn main() { + takes_option(&None); //~ ERROR 4:18: 4:23: mismatched types [E0308] + + let x = String::from("x"); + let res = Some(x); + takes_option(&res); //~ ERROR 8:18: 8:22: mismatched types [E0308] +} diff --git a/src/test/ui/issues/issue-100605.stderr b/src/test/ui/issues/issue-100605.stderr new file mode 100644 index 0000000000000..886e3cd6bb794 --- /dev/null +++ b/src/test/ui/issues/issue-100605.stderr @@ -0,0 +1,46 @@ +error[E0308]: mismatched types + --> $DIR/issue-100605.rs:4:18 + | +LL | takes_option(&None); + | ------------ ^^^^^ expected enum `Option`, found `&Option<_>` + | | + | arguments to this function are incorrect + | + = note: expected enum `Option<&String>` + found reference `&Option<_>` +note: function defined here + --> $DIR/issue-100605.rs:1:4 + | +LL | fn takes_option(_arg: Option<&String>) {} + | ^^^^^^^^^^^^ --------------------- +help: you can convert from `&Option` to `Option<&T>` using `.as_ref()` + | +LL | takes_option(None.as_ref()); + | ~~~~~~~~~~~~~ +help: consider removing the borrow + | +LL - takes_option(&None); +LL + takes_option(None); + | + +error[E0308]: mismatched types + --> $DIR/issue-100605.rs:8:18 + | +LL | takes_option(&res); + | ------------ ^^^^ + | | | + | | expected enum `Option`, found `&Option` + | | help: you can convert from `&Option` to `Option<&T>` using `.as_ref()`: `res.as_ref()` + | arguments to this function are incorrect + | + = note: expected enum `Option<&String>` + found reference `&Option` +note: function defined here + --> $DIR/issue-100605.rs:1:4 + | +LL | fn takes_option(_arg: Option<&String>) {} + | ^^^^^^^^^^^^ --------------------- + +error: aborting due to 2 previous errors + +For more information about this error, try `rustc --explain E0308`.