1 files changed, 44 insertions, 0 deletions
diff --git a/clippy_lints/src/ref_patterns.rs b/clippy_lints/src/ref_patterns.rs
new file mode 100644
index 00000000000..b1530eed1c1
--- /dev/null
+++ b/clippy_lints/src/ref_patterns.rs
@@ -0,0 +1,44 @@
+use clippy_utils::diagnostics::span_lint_and_help;
+use rustc_ast::ast::{BindingAnnotation, Pat, PatKind};
+use rustc_lint::{EarlyContext, EarlyLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+    /// ### What it does
+    /// Checks for usages of the `ref` keyword.
+    /// ### Why is this bad?
+    /// The `ref` keyword can be confusing for people unfamiliar with it, and often
+    /// it is more concise to use `&` instead.
+    /// ### Example
+    /// ```rust
+    /// let opt = Some(5);
+    /// if let Some(ref foo) = opt {}
+    /// ```
+    /// Use instead:
+    /// ```rust
+    /// let opt = Some(5);
+    /// if let Some(foo) = &opt {}
+    /// ```
+    #[clippy::version = "1.71.0"]
+    pub REF_PATTERNS,
+    restriction,
+    "use of a ref pattern, e.g. Some(ref value)"
+}
+declare_lint_pass!(RefPatterns => [REF_PATTERNS]);
+
+impl EarlyLintPass for RefPatterns {
+    fn check_pat(&mut self, cx: &EarlyContext<'_>, pat: &Pat) {
+        if let PatKind::Ident(BindingAnnotation::REF, _, _) = pat.kind
+                && !pat.span.from_expansion()
+        {
+            span_lint_and_help(
+                cx,
+                REF_PATTERNS,
+                pat.span,
+                "usage of ref pattern",
+                None,
+                "consider using `&` for clarity instead",
+            );
+        }
+    }
+}