Rollup merge of #70187 - matthiaskrgr:cl2ppy, r=Mark-Simulacrum

more clippy fixes

    * remove redundant returns (clippy::needless_return)
    * remove redundant import (clippy::single_component_path_imports)
    * remove redundant format!() call (clippy::useless_format)
    * don't use ok() before calling expect() (clippy::ok_expect)

Author: Centril

src/libcore/hint.rs

@@ -114,6 +114,6 @@ pub fn black_box<T>(dummy: T) -> T {
     // more than we want, but it's so far good enough.
     unsafe {
         asm!("" : : "r"(&dummy));
-        return dummy;
+        dummy
     }
 }

src/librustc/lint.rs

@@ -85,7 +85,7 @@ impl LintLevelSets {
             level = cmp::min(*driver_level, level);
         }
 
-        return (level, src);
+        (level, src)
     }
 
     pub fn get_lint_id_level(

src/librustc/middle/region.rs

@@ -467,7 +467,7 @@ impl<'tcx> ScopeTree {
         }
 
         debug!("temporary_scope({:?}) = None", expr_id);
-        return None;
+        None
     }
 
     /// Returns the lifetime of the variable `id`.
@@ -498,7 +498,7 @@ impl<'tcx> ScopeTree {
 
         debug!("is_subscope_of({:?}, {:?})=true", subscope, superscope);
 
-        return true;
+        true
     }
 
     /// Returns the ID of the innermost containing body.

src/librustc/ty/context.rs

@@ -1447,11 +1447,11 @@ impl<'tcx> TyCtxt<'tcx> {
             _ => return None,
         };
 
-        return Some(FreeRegionInfo {
+        Some(FreeRegionInfo {
             def_id: suitable_region_binding_scope,
             boundregion: bound_region,
             is_impl_item,
-        });
+        })
     }
 
     pub fn return_type_impl_trait(&self, scope_def_id: DefId) -> Option<(Ty<'tcx>, Span)> {

src/librustc/ty/relate.rs

@@ -440,7 +440,7 @@ pub fn super_relate_tys<R: TypeRelation<'tcx>>(
                         (Some(sz_a_val), Some(sz_b_val)) => Err(TypeError::FixedArraySize(
                             expected_found(relation, &sz_a_val, &sz_b_val),
                         )),
-                        _ => return Err(err),
+                        _ => Err(err),
                     }
                 }
             }

src/librustc/ty/sty.rs

@@ -1612,7 +1612,7 @@ impl<'tcx> PolyExistentialProjection<'tcx> {
     }
 
     pub fn item_def_id(&self) -> DefId {
-        return self.skip_binder().item_def_id;
+        self.skip_binder().item_def_id
     }
 }
 
@@ -2000,8 +2000,8 @@ impl<'tcx> TyS<'tcx> {
     #[inline]
     pub fn is_unsafe_ptr(&self) -> bool {
         match self.kind {
-            RawPtr(_) => return true,
-            _ => return false,
+            RawPtr(_) => true,
+            _ => false,
         }
     }
 

src/librustc/ty/subst.rs

@@ -524,7 +524,7 @@ impl<'a, 'tcx> TypeFolder<'tcx> for SubstFolder<'a, 'tcx> {
             self.root_ty = None;
         }
 
-        return t1;
+        t1
     }
 
     fn fold_const(&mut self, c: &'tcx ty::Const<'tcx>) -> &'tcx ty::Const<'tcx> {

src/librustc_builtin_macros/deriving/decodable.rs

@@ -87,7 +87,7 @@ fn decodable_substructure(
     let blkarg = cx.ident_of("_d", trait_span);
     let blkdecoder = cx.expr_ident(trait_span, blkarg);
 
-    return match *substr.fields {
+    match *substr.fields {
         StaticStruct(_, ref summary) => {
             let nfields = match *summary {
                 Unnamed(ref fields, _) => fields.len(),
@@ -178,7 +178,7 @@ fn decodable_substructure(
             )
         }
         _ => cx.bug("expected StaticEnum or StaticStruct in derive(Decodable)"),
-    };
+    }
 }
 
 /// Creates a decoder for a single enum variant/struct:

src/librustc_builtin_macros/deriving/default.rs

@@ -53,7 +53,7 @@ fn default_substructure(
     let default_ident = cx.std_path(&[kw::Default, sym::Default, kw::Default]);
     let default_call = |span| cx.expr_call_global(span, default_ident.clone(), Vec::new());
 
-    return match *substr.fields {
+    match *substr.fields {
         StaticStruct(_, ref summary) => match *summary {
             Unnamed(ref fields, is_tuple) => {
                 if !is_tuple {
@@ -83,5 +83,5 @@ fn default_substructure(
             DummyResult::raw_expr(trait_span, true)
         }
         _ => cx.span_bug(trait_span, "method in `derive(Default)`"),
-    };
+    }
 }

src/librustc_builtin_macros/deriving/encodable.rs

@@ -173,7 +173,7 @@ fn encodable_substructure(
         ],
     ));
 
-    return match *substr.fields {
+    match *substr.fields {
         Struct(_, ref fields) => {
             let emit_struct_field = cx.ident_of("emit_struct_field", trait_span);
             let mut stmts = Vec::new();
@@ -283,5 +283,5 @@ fn encodable_substructure(
         }
 
         _ => cx.bug("expected Struct or EnumMatching in derive(Encodable)"),
-    };
+    }
 }