diff --git a/compiler/rustc_codegen_ssa/src/mir/block.rs b/compiler/rustc_codegen_ssa/src/mir/block.rs
index ce56f1635495e8082cdcab3be0e68e515d2217e9..ecac05fd955720b35a1b291f46e5fbf963466d4a 100644
--- a/compiler/rustc_codegen_ssa/src/mir/block.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/block.rs
@@ -522,7 +522,7 @@ fn codegen_call_terminator(
         mut bx: Bx,
         terminator: &mir::Terminator<'tcx>,
         func: &mir::Operand<'tcx>,
-        args: &Vec<mir::Operand<'tcx>>,
+        args: &[mir::Operand<'tcx>],
         destination: &Option<(mir::Place<'tcx>, mir::BasicBlock)>,
         cleanup: Option<mir::BasicBlock>,
         fn_span: Span,
diff --git a/compiler/rustc_driver/src/lib.rs b/compiler/rustc_driver/src/lib.rs
index b3466f49b9f2582678d60c1044cfeac543dac745..d57ab2433ad1b291c0306046e3de028d9b253e72 100644
--- a/compiler/rustc_driver/src/lib.rs
+++ b/compiler/rustc_driver/src/lib.rs
@@ -603,7 +603,7 @@ fn handle_explain(registry: Registry, code: &str, output: ErrorOutputType) {
     }
 }
 
-fn show_content_with_pager(content: &String) {
+fn show_content_with_pager(content: &str) {
     let pager_name = env::var_os("PAGER").unwrap_or_else(|| {
         if cfg!(windows) { OsString::from("more.com") } else { OsString::from("less") }
     });
diff --git a/compiler/rustc_infer/src/infer/error_reporting/mod.rs b/compiler/rustc_infer/src/infer/error_reporting/mod.rs
index 6b7edde9a67aff756474a48c4ee55ae7bbd303c5..6d6bf4bf5f7058d750a1cd8fd852e0e93a3a9d03 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/mod.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/mod.rs
@@ -417,7 +417,7 @@ pub fn report_region_errors(&self, errors: &Vec<RegionResolutionError<'tcx>>) {
     // obviously it never weeds out ALL errors.
     fn process_errors(
         &self,
-        errors: &Vec<RegionResolutionError<'tcx>>,
+        errors: &[RegionResolutionError<'tcx>],
     ) -> Vec<RegionResolutionError<'tcx>> {
         debug!("process_errors()");
 
@@ -442,7 +442,7 @@ fn process_errors(
         };
 
         let mut errors = if errors.iter().all(|e| is_bound_failure(e)) {
-            errors.clone()
+            errors.to_owned()
         } else {
             errors.iter().filter(|&e| !is_bound_failure(e)).cloned().collect()
         };
diff --git a/compiler/rustc_macros/src/session_diagnostic.rs b/compiler/rustc_macros/src/session_diagnostic.rs
index 610b9155cfc182059d58a39901bd3be03dd46585..5c061a9d3c7949a529c077090889d80a51265a8b 100644
--- a/compiler/rustc_macros/src/session_diagnostic.rs
+++ b/compiler/rustc_macros/src/session_diagnostic.rs
@@ -574,7 +574,7 @@ fn generate_non_option_field_code(
     /// format!("Expected a point greater than ({x}, {y})", x = self.x, y = self.y)
     /// ```
     /// This function builds the entire call to format!.
-    fn build_format(&self, input: &String, span: proc_macro2::Span) -> proc_macro2::TokenStream {
+    fn build_format(&self, input: &str, span: proc_macro2::Span) -> proc_macro2::TokenStream {
         // This set is used later to generate the final format string. To keep builds reproducible,
         // the iteration order needs to be deterministic, hence why we use a BTreeSet here instead
         // of a HashSet.
diff --git a/compiler/rustc_mir/src/borrow_check/diagnostics/mod.rs b/compiler/rustc_mir/src/borrow_check/diagnostics/mod.rs
index 81571fd73003fb448587f786462b289c693b792b..4ebc1cdca60597ec83d4c2c54a3639fc5197c505 100644
--- a/compiler/rustc_mir/src/borrow_check/diagnostics/mod.rs
+++ b/compiler/rustc_mir/src/borrow_check/diagnostics/mod.rs
@@ -954,7 +954,7 @@ fn closure_span(
         &self,
         def_id: DefId,
         target_place: PlaceRef<'tcx>,
-        places: &Vec<Operand<'tcx>>,
+        places: &[Operand<'tcx>],
     ) -> Option<(Span, Option<GeneratorKind>, Span)> {
         debug!(
             "closure_span: def_id={:?} target_place={:?} places={:?}",
diff --git a/compiler/rustc_mir/src/borrow_check/type_check/liveness/local_use_map.rs b/compiler/rustc_mir/src/borrow_check/type_check/liveness/local_use_map.rs
index 995e3a60a0c76fa8c6e2083a10a93bfbc93577d6..7e8a33efe114ef6fb6a275c5a1b2a1fb70c170a2 100644
--- a/compiler/rustc_mir/src/borrow_check/type_check/liveness/local_use_map.rs
+++ b/compiler/rustc_mir/src/borrow_check/type_check/liveness/local_use_map.rs
@@ -58,11 +58,7 @@ fn next(elem: &Self) -> Option<AppearanceIndex> {
 }
 
 impl LocalUseMap {
-    crate fn build(
-        live_locals: &Vec<Local>,
-        elements: &RegionValueElements,
-        body: &Body<'_>,
-    ) -> Self {
+    crate fn build(live_locals: &[Local], elements: &RegionValueElements, body: &Body<'_>) -> Self {
         let nones = IndexVec::from_elem_n(None, body.local_decls.len());
         let mut local_use_map = LocalUseMap {
             first_def_at: nones.clone(),
diff --git a/compiler/rustc_mir/src/interpret/validity.rs b/compiler/rustc_mir/src/interpret/validity.rs
index 57aec0953b8c29e24e228465f0f94d6c42db8afb..a6ea039f278a1e595c0dcb848a6c41c093419ec5 100644
--- a/compiler/rustc_mir/src/interpret/validity.rs
+++ b/compiler/rustc_mir/src/interpret/validity.rs
@@ -153,7 +153,7 @@ pub fn track(&mut self, op: T, path: impl FnOnce() -> PATH) {
 }
 
 /// Format a path
-fn write_path(out: &mut String, path: &Vec<PathElem>) {
+fn write_path(out: &mut String, path: &[PathElem]) {
     use self::PathElem::*;
 
     for elem in path.iter() {
diff --git a/compiler/rustc_mir/src/transform/coverage/counters.rs b/compiler/rustc_mir/src/transform/coverage/counters.rs
index 20f6a16e0f75712190548ed9aa573a4310f4f673..b5921aac561437326c851914cdb1baa68f0dd0a6 100644
--- a/compiler/rustc_mir/src/transform/coverage/counters.rs
+++ b/compiler/rustc_mir/src/transform/coverage/counters.rs
@@ -140,7 +140,7 @@ fn new(
     /// message for subsequent debugging.
     fn make_bcb_counters(
         &mut self,
-        coverage_spans: &Vec<CoverageSpan>,
+        coverage_spans: &[CoverageSpan],
     ) -> Result<Vec<CoverageKind>, Error> {
         debug!("make_bcb_counters(): adding a counter or expression to each BasicCoverageBlock");
         let num_bcbs = self.basic_coverage_blocks.num_nodes();
@@ -465,7 +465,7 @@ fn recursive_get_or_make_edge_counter_operand(
     fn choose_preferred_expression_branch(
         &self,
         traversal: &TraverseCoverageGraphWithLoops,
-        branches: &Vec<BcbBranch>,
+        branches: &[BcbBranch],
     ) -> BcbBranch {
         let branch_needs_a_counter =
             |branch: &BcbBranch| branch.counter(&self.basic_coverage_blocks).is_none();
@@ -509,7 +509,7 @@ fn choose_preferred_expression_branch(
     fn find_some_reloop_branch(
         &self,
         traversal: &TraverseCoverageGraphWithLoops,
-        branches: &Vec<BcbBranch>,
+        branches: &[BcbBranch],
     ) -> Option<BcbBranch> {
         let branch_needs_a_counter =
             |branch: &BcbBranch| branch.counter(&self.basic_coverage_blocks).is_none();
diff --git a/compiler/rustc_mir/src/transform/function_item_references.rs b/compiler/rustc_mir/src/transform/function_item_references.rs
index d592580af9cecf8c59f1a553279af679c67d8b4d..7c8c349da1d6c55544d01e2b49d9e888394267cf 100644
--- a/compiler/rustc_mir/src/transform/function_item_references.rs
+++ b/compiler/rustc_mir/src/transform/function_item_references.rs
@@ -99,7 +99,7 @@ fn check_bound_args(
         &self,
         def_id: DefId,
         substs_ref: SubstsRef<'tcx>,
-        args: &Vec<Operand<'tcx>>,
+        args: &[Operand<'tcx>],
         source_info: SourceInfo,
     ) {
         let param_env = self.tcx.param_env(def_id);
@@ -162,7 +162,7 @@ fn is_fn_ref(ty: Ty<'tcx>) -> Option<(DefId, SubstsRef<'tcx>)> {
             .unwrap_or(None)
     }
 
-    fn nth_arg_span(&self, args: &Vec<Operand<'tcx>>, n: usize) -> Span {
+    fn nth_arg_span(&self, args: &[Operand<'tcx>], n: usize) -> Span {
         match &args[n] {
             Operand::Copy(place) | Operand::Move(place) => {
                 self.body.local_decls[place.local].source_info.span
diff --git a/compiler/rustc_mir_build/src/build/expr/as_place.rs b/compiler/rustc_mir_build/src/build/expr/as_place.rs
index e1a3dc87c8c8dc696a21971c946295fa7da0b631..cf2e4e8916d0a397c5f8b320f8acf39951417687 100644
--- a/compiler/rustc_mir_build/src/build/expr/as_place.rs
+++ b/compiler/rustc_mir_build/src/build/expr/as_place.rs
@@ -79,7 +79,7 @@
 /// part of a path that is captued by a closure. We stop applying projections once we see the first
 /// projection that isn't captured by a closure.
 fn convert_to_hir_projections_and_truncate_for_capture<'tcx>(
-    mir_projections: &Vec<PlaceElem<'tcx>>,
+    mir_projections: &[PlaceElem<'tcx>],
 ) -> Vec<HirProjectionKind> {
 
     let mut hir_projections  = Vec::new();
@@ -128,7 +128,7 @@ fn convert_to_hir_projections_and_truncate_for_capture<'tcx>(
 ///        list are being applied to the same root variable.
 fn is_ancestor_or_same_capture(
     proj_possible_ancestor: &Vec<HirProjectionKind>,
-    proj_capture: &Vec<HirProjectionKind>,
+    proj_capture: &[HirProjectionKind],
 ) -> bool {
     // We want to make sure `is_ancestor_or_same_capture("x.0.0", "x.0")` to return false.
     // Therefore we can't just check if all projections are same in the zipped iterator below.
@@ -171,7 +171,7 @@ fn find_capture_matching_projections<'a, 'tcx>(
     typeck_results: &'a ty::TypeckResults<'tcx>,
     var_hir_id: HirId,
     closure_def_id: DefId,
-    projections: &Vec<PlaceElem<'tcx>>,
+    projections: &[PlaceElem<'tcx>],
 ) -> Option<(usize, &'a ty::CapturedPlace<'tcx>)> {
     let closure_min_captures = typeck_results.closure_min_captures.get(&closure_def_id)?;
     let root_variable_min_captures = closure_min_captures.get(&var_hir_id)?;
diff --git a/compiler/rustc_resolve/src/late.rs b/compiler/rustc_resolve/src/late.rs
index b13462587bc618ef55762577dd16a818ebb424a1..21def3e142910cb77cd88dade0e1dafd0631cba2 100644
--- a/compiler/rustc_resolve/src/late.rs
+++ b/compiler/rustc_resolve/src/late.rs
@@ -1151,13 +1151,11 @@ fn with_current_self_item<T>(&mut self, self_item: &Item, f: impl FnOnce(&mut Se
     /// When evaluating a `trait` use its associated types' idents for suggestions in E0412.
     fn with_trait_items<T>(
         &mut self,
-        trait_items: &'ast Vec<P<AssocItem>>,
+        trait_items: &'ast [P<AssocItem>],
         f: impl FnOnce(&mut Self) -> T,
     ) -> T {
-        let trait_assoc_items = replace(
-            &mut self.diagnostic_metadata.current_trait_assoc_items,
-            Some(&trait_items[..]),
-        );
+        let trait_assoc_items =
+            replace(&mut self.diagnostic_metadata.current_trait_assoc_items, Some(&trait_items));
         let result = f(self);
         self.diagnostic_metadata.current_trait_assoc_items = trait_assoc_items;
         result
diff --git a/compiler/rustc_session/src/filesearch.rs b/compiler/rustc_session/src/filesearch.rs
index 55ee4e52082e51e3b10c57e4fc7dd2db3126b391..3a757e5f0075d468b77e1f5d02873231d0e51a0c 100644
--- a/compiler/rustc_session/src/filesearch.rs
+++ b/compiler/rustc_session/src/filesearch.rs
@@ -76,7 +76,7 @@ fn is_rlib(spf: &SearchPathFile) -> bool {
     pub fn new(
         sysroot: &'a Path,
         triple: &'a str,
-        search_paths: &'a Vec<SearchPath>,
+        search_paths: &'a [SearchPath],
         tlib_path: &'a SearchPath,
         kind: PathKind,
     ) -> FileSearch<'a> {
diff --git a/src/librustdoc/html/render/mod.rs b/src/librustdoc/html/render/mod.rs
index 6f8a4d9513ba7bdf21de0d280722a2fcff61fa76..04876c1d3f0a63151da5735cb9a8d5503cb5d583 100644
--- a/src/librustdoc/html/render/mod.rs
+++ b/src/librustdoc/html/render/mod.rs
@@ -3483,7 +3483,7 @@ enum AssocItemLink<'a> {
 }
 
 impl<'a> AssocItemLink<'a> {
-    fn anchor(&self, id: &'a String) -> Self {
+    fn anchor(&self, id: &'a str) -> Self {
         match *self {
             AssocItemLink::Anchor(_) => AssocItemLink::Anchor(Some(&id)),
             ref other => *other,