Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/ide-diagnostics/src/handlers/cannot_implicitly_deref_trait_object.rs')
-rw-r--r--crates/ide-diagnostics/src/handlers/cannot_implicitly_deref_trait_object.rs53
1 files changed, 53 insertions, 0 deletions
diff --git a/crates/ide-diagnostics/src/handlers/cannot_implicitly_deref_trait_object.rs b/crates/ide-diagnostics/src/handlers/cannot_implicitly_deref_trait_object.rs
new file mode 100644
index 0000000000..eca14144dd
--- /dev/null
+++ b/crates/ide-diagnostics/src/handlers/cannot_implicitly_deref_trait_object.rs
@@ -0,0 +1,53 @@
+use hir::HirDisplay;
+
+use crate::{Diagnostic, DiagnosticCode, DiagnosticsContext};
+
+// Diagnostic: cannot-implicitly-deref-trait-object
+//
+// This diagnostic is triggered when a pointer to a trait object is implicitly
+// dereferenced by a pattern.
+pub(crate) fn cannot_implicitly_deref_trait_object(
+ ctx: &DiagnosticsContext<'_, '_>,
+ d: &hir::CannotImplicitlyDerefTraitObject<'_>,
+) -> Diagnostic {
+ Diagnostic::new_with_syntax_node_ptr(
+ ctx,
+ DiagnosticCode::RustcHardError("E0033"),
+ format!(
+ "type `{}` cannot be dereferenced",
+ d.found.display(ctx.sema.db, ctx.display_target)
+ ),
+ d.pat.map(Into::into),
+ )
+ .stable()
+}
+
+#[cfg(test)]
+mod tests {
+ use crate::tests::check_diagnostics;
+
+ #[test]
+ fn trait_object_pattern_deref() {
+ check_diagnostics(
+ r#"
+trait Trait {}
+
+fn f(x: &dyn Trait) {
+ let &ref _y = x;
+ //^^^^^^^ error: type `&(dyn Trait + 'static)` cannot be dereferenced
+}
+"#,
+ );
+ }
+
+ #[test]
+ fn allows_sized_ref_pattern_deref() {
+ check_diagnostics(
+ r#"
+fn f(x: &i32) {
+ let &ref _y = x;
+}
+"#,
+ );
+ }
+}