Add lint manual_split_once

clippy_utils/src/diagnostics.rs

@@ -21,7 +21,7 @@ fn docs_link(diag: &mut DiagnosticBuilder<'_>, lint: &'static Lint) {
                 "for further information visit https://rust-lang.github.io/rust-clippy/{}/index.html#{}",
                 &option_env!("RUST_RELEASE_NUM").map_or("master".to_string(), |n| {
                     // extract just major + minor version and ignore patch versions
-                    format!("rust-{}", n.rsplitn(2, '.').nth(1).unwrap())
+                    format!("rust-{}", n.rsplit_once('.').unwrap().1)
                 }),
                 lint
             ));

clippy_utils/src/msrvs.rs

@@ -13,6 +13,7 @@ macro_rules! msrv_aliases {
 // names may refer to stabilized feature flags or library items
 msrv_aliases! {
     1,53,0 { OR_PATTERNS }
+    1,52,0 { STR_SPLIT_ONCE }
     1,50,0 { BOOL_THEN }
     1,46,0 { CONST_IF_MATCH }
     1,45,0 { STR_STRIP_PREFIX }

clippy_utils/src/paths.rs

@@ -68,6 +68,7 @@ pub const IO_WRITE: [&str; 3] = ["std", "io", "Write"];
 pub const IPADDR_V4: [&str; 5] = ["std", "net", "ip", "IpAddr", "V4"];
 pub const IPADDR_V6: [&str; 5] = ["std", "net", "ip", "IpAddr", "V6"];
 pub const ITER_REPEAT: [&str; 5] = ["core", "iter", "sources", "repeat", "repeat"];
+pub const ITERTOOLS_NEXT_TUPLE: [&str; 3] = ["itertools", "Itertools", "next_tuple"];
 #[cfg(feature = "internal-lints")]
 pub const KW_MODULE: [&str; 3] = ["rustc_span", "symbol", "kw"];
 #[cfg(feature = "internal-lints")]

clippy_utils/src/visitors.rs

@@ -147,22 +147,23 @@ macro_rules! visitable_ref {
             }
         }
     };
-    ([$t:ident], $f:ident) => {
-        impl Visitable<'tcx> for &'tcx [$t<'tcx>] {
-            fn visit<V: Visitor<'tcx>>(self, visitor: &mut V) {
-                for x in self {
-                    visitor.$f(x);
-                }
-            }
-        }
-    };
 }
 visitable_ref!(Arm, visit_arm);
 visitable_ref!(Block, visit_block);
 visitable_ref!(Body, visit_body);
 visitable_ref!(Expr, visit_expr);
 visitable_ref!(Stmt, visit_stmt);
-visitable_ref!([Stmt], visit_stmt);
+
+// impl<'tcx, I: IntoIterator> Visitable<'tcx> for I
+// where
+//     I::Item: Visitable<'tcx>,
+// {
+//     fn visit<V: Visitor<'tcx>>(self, visitor: &mut V) {
+//         for x in self {
+//             x.visit(visitor);
+//         }
+//     }
+// }
 
 /// Calls the given function for each break expression.
 pub fn visit_break_exprs<'tcx>(