Auto merge of #71201 - Dylan-DPC:rollup-23202uf, r=Dylan-DPC

Rollup of 5 pull requests

Successful merges:

 - #70566 (Don't bail out before linting in generic contexts.)
 - #71141 (Provide better compiler output when using `?` on `Option` in fn returning `Result` and vice-versa)
 - #71149 (remove an impossible branch from check_consts)
 - #71179 (fix more clippy warnings)
 - #71191 (Clean up E0520 explanation)

Failed merges:

r? @ghost

Author: bors

src/liballoc/vec.rs

@@ -971,7 +971,7 @@ impl<T> Vec<T> {
         }
 
         let len = self.len();
-        if !(index < len) {
+        if index >= len {
             assert_failed(index, len);
         }
         unsafe {
@@ -1010,7 +1010,7 @@ impl<T> Vec<T> {
         }
 
         let len = self.len();
-        if !(index <= len) {
+        if index > len {
             assert_failed(index, len);
         }
 
@@ -1058,7 +1058,7 @@ impl<T> Vec<T> {
         }
 
         let len = self.len();
-        if !(index < len) {
+        if index >= len {
             assert_failed(index, len);
         }
         unsafe {
@@ -1331,10 +1331,10 @@ impl<T> Vec<T> {
             panic!("end drain index (is {}) should be <= len (is {})", end, len);
         }
 
-        if !(start <= end) {
+        if start > end {
             start_assert_failed(start, end);
         }
-        if !(end <= len) {
+        if end > len {
             end_assert_failed(end, len);
         }
 
@@ -1432,7 +1432,7 @@ impl<T> Vec<T> {
             panic!("`at` split index (is {}) should be <= len (is {})", at, len);
         }
 
-        if !(at <= self.len()) {
+        if at > self.len() {
             assert_failed(at, self.len());
         }
 

src/librustc_builtin_macros/deriving/debug.rs

@@ -63,7 +63,7 @@ fn show_substructure(cx: &mut ExtCtxt<'_>, span: Span, substr: &Substructure<'_>
     let span = cx.with_def_site_ctxt(span);
     let name = cx.expr_lit(span, ast::LitKind::Str(ident.name, ast::StrStyle::Cooked));
     let builder = cx.ident_of("debug_trait_builder", span);
-    let builder_expr = cx.expr_ident(span, builder.clone());
+    let builder_expr = cx.expr_ident(span, builder);
 
     let fmt = substr.nonself_args[0].clone();
 

src/librustc_error_codes/error_codes/E0520.md

@@ -1,5 +1,7 @@
 A non-default implementation was already made on this type so it cannot be
-specialized further. Erroneous code example:
+specialized further.
+
+Erroneous code example:
 
 ```compile_fail,E0520
 #![feature(specialization)]

src/librustc_errors/emitter.rs

@@ -2005,7 +2005,7 @@ fn emit_to_destination(
     let _buffer_lock = lock::acquire_global_lock("rustc_errors");
     for (pos, line) in rendered_buffer.iter().enumerate() {
         for part in line {
-            dst.apply_style(lvl.clone(), part.style)?;
+            dst.apply_style(*lvl, part.style)?;
             write!(dst, "{}", part.text)?;
             dst.reset()?;
         }

src/librustc_infer/infer/error_reporting/mod.rs

@@ -871,7 +871,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
                 return Some(());
             }
             if let &ty::Adt(def, _) = &ta.kind {
-                let path_ = self.tcx.def_path_str(def.did.clone());
+                let path_ = self.tcx.def_path_str(def.did);
                 if path_ == other_path {
                     self.highlight_outer(&mut t1_out, &mut t2_out, path, sub, i, &other_ty);
                     return Some(());
@@ -1091,8 +1091,8 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
                 let sub_no_defaults_1 = self.strip_generic_default_params(def1.did, sub1);
                 let sub_no_defaults_2 = self.strip_generic_default_params(def2.did, sub2);
                 let mut values = (DiagnosticStyledString::new(), DiagnosticStyledString::new());
-                let path1 = self.tcx.def_path_str(def1.did.clone());
-                let path2 = self.tcx.def_path_str(def2.did.clone());
+                let path1 = self.tcx.def_path_str(def1.did);
+                let path2 = self.tcx.def_path_str(def2.did);
                 if def1.did == def2.did {
                     // Easy case. Replace same types with `_` to shorten the output and highlight
                     // the differing ones.

src/librustc_infer/infer/outlives/obligations.rs

@@ -452,7 +452,7 @@ where
         // even though a satisfactory solution exists.
         let generic = GenericKind::Projection(projection_ty);
         let verify_bound = self.verify_bound.generic_bound(generic);
-        self.delegate.push_verify(origin, generic.clone(), region, verify_bound);
+        self.delegate.push_verify(origin, generic, region, verify_bound);
     }
 }
 

src/librustc_infer/infer/outlives/verify.rs

@@ -297,7 +297,6 @@ impl<'cx, 'tcx> VerifyBoundCx<'cx, 'tcx> {
         self.collect_outlives_from_predicate_list(
             move |ty| ty == identity_proj,
             traits::elaborate_predicates(tcx, trait_predicates)
-                .into_iter()
                 .map(|o| o.predicate)
                 .collect::<Vec<_>>(),
         )

src/librustc_mir/borrow_check/mod.rs

@@ -1056,7 +1056,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                                  place: {:?}",
                                 place_span.0
                             );
-                            this.reservation_error_reported.insert(place_span.0.clone());
+                            this.reservation_error_reported.insert(place_span.0);
                         }
                         Activation(_, activating) => {
                             debug!(

src/librustc_mir/borrow_check/region_infer/mod.rs

@@ -495,7 +495,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
         // to store those. Otherwise, we'll pass in `None` to the
         // functions below, which will trigger them to report errors
         // eagerly.
-        let mut outlives_requirements = infcx.tcx.is_closure(mir_def_id).then(|| vec![]);
+        let mut outlives_requirements = infcx.tcx.is_closure(mir_def_id).then(Vec::new);
 
         self.check_type_tests(infcx, body, outlives_requirements.as_mut(), &mut errors_buffer);
 

src/librustc_mir/dataflow/move_paths/builder.rs

@@ -286,7 +286,7 @@ impl<'b, 'a, 'tcx> Gatherer<'b, 'a, 'tcx> {
                     // Box starts out uninitialized - need to create a separate
                     // move-path for the interior so it will be separate from
                     // the exterior.
-                    self.create_move_path(self.builder.tcx.mk_place_deref(place.clone()));
+                    self.create_move_path(self.builder.tcx.mk_place_deref(*place));
                     self.gather_init(place.as_ref(), InitKind::Shallow);
                 } else {
                     self.gather_init(place.as_ref(), InitKind::Deep);
@@ -458,9 +458,8 @@ impl<'b, 'a, 'tcx> Gatherer<'b, 'a, 'tcx> {
             for offset in from..to {
                 let elem =
                     ProjectionElem::ConstantIndex { offset, min_length: len, from_end: false };
-                let path = self.add_move_path(base_path, &elem, |tcx| {
-                    tcx.mk_place_elem(base_place.clone(), elem)
-                });
+                let path =
+                    self.add_move_path(base_path, &elem, |tcx| tcx.mk_place_elem(base_place, elem));
                 self.record_move(place, path);
             }
         } else {