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| author | yukang <moorekang@gmail.com> | 2022-08-20 09:43:37 +0800 |
|---|---|---|
| committer | yukang <moorekang@gmail.com> | 2022-08-20 09:43:37 +0800 |
| commit | 3de74f7e2be7be983aaef0fe7be08e9030e4ecbb (patch) | |
| tree | f5cab361b82580d702c5fcf67f20e55ea6434b8d | |
| parent | 1603a70f82240ba2d27f72f964e36614d7620ad3 (diff) | |
| download | rust-3de74f7e2be7be983aaef0fe7be08e9030e4ecbb.tar.gz rust-3de74f7e2be7be983aaef0fe7be08e9030e4ecbb.zip | |
Suggest the right help message for as_ref
| -rw-r--r-- | compiler/rustc_infer/src/infer/error_reporting/mod.rs | 3 | ||||
| -rw-r--r-- | src/test/ui/issues/issue-100605.rs | 9 | ||||
| -rw-r--r-- | src/test/ui/issues/issue-100605.stderr | 46 |
3 files changed, 57 insertions, 1 deletions
diff --git a/compiler/rustc_infer/src/infer/error_reporting/mod.rs b/compiler/rustc_infer/src/infer/error_reporting/mod.rs index 20864c657ff..529ddf03a8c 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<T> 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 00000000000..917a45c15bb --- /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 00000000000..886e3cd6bb7 --- /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<T>` 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<String>` + | | help: you can convert from `&Option<T>` to `Option<&T>` using `.as_ref()`: `res.as_ref()` + | arguments to this function are incorrect + | + = note: expected enum `Option<&String>` + found reference `&Option<String>` +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`. |