rustc_lint: deny(unused_lifetimes).

Author: eddyb

src/librustc_lint/builtin.rs

@@ -96,7 +96,7 @@ declare_lint! {
 declare_lint_pass!(BoxPointers => [BOX_POINTERS]);
 
 impl BoxPointers {
-    fn check_heap_type<'a, 'tcx>(&self, cx: &LateContext<'_, '_>, span: Span, ty: Ty<'_>) {
+    fn check_heap_type(&self, cx: &LateContext<'_, '_>, span: Span, ty: Ty<'_>) {
         for leaf_ty in ty.walk() {
             if leaf_ty.is_box() {
                 let m = format!("type uses owned (Box type) pointers: {}", ty);

src/librustc_lint/lib.rs

@@ -21,6 +21,7 @@
 
 #![deny(rust_2018_idioms)]
 #![deny(internal)]
+#![deny(unused_lifetimes)]
 
 #[macro_use]
 extern crate rustc;

src/librustc_lint/types.rs

@@ -202,7 +202,7 @@ fn report_bin_hex_error(
 //  - `uX` => `uY`
 //
 // No suggestion for: `isize`, `usize`.
-fn get_type_suggestion<'a>(
+fn get_type_suggestion(
     t: Ty<'_>,
     val: u128,
     negative: bool,