1 files changed, 50 insertions, 0 deletions
diff --git a/src/tools/clippy/clippy_lints/src/methods/is_digit_ascii_radix.rs b/src/tools/clippy/clippy_lints/src/methods/is_digit_ascii_radix.rs
new file mode 100644
index 000000000..aa176dcc8
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/methods/is_digit_ascii_radix.rs
@@ -0,0 +1,50 @@
+//! Lint for `c.is_digit(10)`
+
+use super::IS_DIGIT_ASCII_RADIX;
+use clippy_utils::{
+    consts::constant_full_int, consts::FullInt, diagnostics::span_lint_and_sugg, meets_msrv, msrvs,
+    source::snippet_with_applicability,
+};
+use rustc_errors::Applicability;
+use rustc_hir::Expr;
+use rustc_lint::LateContext;
+use rustc_semver::RustcVersion;
+
+pub(super) fn check<'tcx>(
+    cx: &LateContext<'tcx>,
+    expr: &'tcx Expr<'_>,
+    self_arg: &'tcx Expr<'_>,
+    radix: &'tcx Expr<'_>,
+    msrv: Option<RustcVersion>,
+) {
+    if !meets_msrv(msrv, msrvs::IS_ASCII_DIGIT) {
+        return;
+    }
+
+    if !cx.typeck_results().expr_ty_adjusted(self_arg).peel_refs().is_char() {
+        return;
+    }
+
+    if let Some(radix_val) = constant_full_int(cx, cx.typeck_results(), radix) {
+        let (num, replacement) = match radix_val {
+            FullInt::S(10) | FullInt::U(10) => (10, "is_ascii_digit"),
+            FullInt::S(16) | FullInt::U(16) => (16, "is_ascii_hexdigit"),
+            _ => return,
+        };
+        let mut applicability = Applicability::MachineApplicable;
+
+        span_lint_and_sugg(
+            cx,
+            IS_DIGIT_ASCII_RADIX,
+            expr.span,
+            &format!("use of `char::is_digit` with literal radix of {}", num),
+            "try",
+            format!(
+                "{}.{}()",
+                snippet_with_applicability(cx, self_arg.span, "..", &mut applicability),
+                replacement
+            ),
+            applicability,
+        );
+    }
+}