diff --git a/src/librustc/ty/query/plumbing.rs b/src/librustc/ty/query/plumbing.rs
index acf67f52dce..3d59fc78211 100644
--- a/src/librustc/ty/query/plumbing.rs
+++ b/src/librustc/ty/query/plumbing.rs
@@ -692,7 +692,7 @@ impl<'tcx> TyCtxt<'tcx> {
     /// side-effects -- e.g., in order to report errors for erroneous programs.
     ///
     /// Note: The optimization is only available during incr. comp.
-    pub(super) fn ensure_query<Q: QueryDescription<'tcx> + 'tcx>(self, key: Q::Key) -> () {
+    pub(super) fn ensure_query<Q: QueryDescription<'tcx> + 'tcx>(self, key: Q::Key) {
         if Q::EVAL_ALWAYS {
             let _ = self.get_query::<Q>(DUMMY_SP, key);
             return;
diff --git a/src/librustc_mir/const_eval/machine.rs b/src/librustc_mir/const_eval/machine.rs
index d81aae6523a..87d0424ece9 100644
--- a/src/librustc_mir/const_eval/machine.rs
+++ b/src/librustc_mir/const_eval/machine.rs
@@ -335,9 +335,7 @@ impl<'mir, 'tcx> interpret::Machine<'mir, 'tcx> for CompileTimeInterpreter<'mir,
     }
 
     #[inline(always)]
-    fn tag_static_base_pointer(_memory_extra: &MemoryExtra, _id: AllocId) -> Self::PointerTag {
-        ()
-    }
+    fn tag_static_base_pointer(_memory_extra: &MemoryExtra, _id: AllocId) -> Self::PointerTag {}
 
     fn box_alloc(
         _ecx: &mut InterpCx<'mir, 'tcx, Self>,
diff --git a/src/librustc_mir/transform/const_prop.rs b/src/librustc_mir/transform/const_prop.rs
index 8d7cafc34b3..ba29b187b22 100644
--- a/src/librustc_mir/transform/const_prop.rs
+++ b/src/librustc_mir/transform/const_prop.rs
@@ -232,9 +232,7 @@ impl<'mir, 'tcx> interpret::Machine<'mir, 'tcx> for ConstPropMachine {
     }
 
     #[inline(always)]
-    fn tag_static_base_pointer(_memory_extra: &(), _id: AllocId) -> Self::PointerTag {
-        ()
-    }
+    fn tag_static_base_pointer(_memory_extra: &(), _id: AllocId) -> Self::PointerTag {}
 
     fn box_alloc(
         _ecx: &mut InterpCx<'mir, 'tcx, Self>,
diff --git a/src/librustc_mir_build/build/expr/as_temp.rs b/src/librustc_mir_build/build/expr/as_temp.rs
index 34dd10cbc0f..82183e6c96e 100644
--- a/src/librustc_mir_build/build/expr/as_temp.rs
+++ b/src/librustc_mir_build/build/expr/as_temp.rs
@@ -73,10 +73,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
             // they are never assigned.
             ExprKind::Break { .. } | ExprKind::Continue { .. } | ExprKind::Return { .. } => (),
             ExprKind::Block { body: hir::Block { expr: None, targeted_by_break: false, .. } }
-                if expr_ty.is_never() =>
-            {
-                ()
-            }
+                if expr_ty.is_never() => {}
             _ => {
                 this.cfg
                     .push(block, Statement { source_info, kind: StatementKind::StorageLive(temp) });
diff --git a/src/librustc_target/spec/apple_sdk_base.rs b/src/librustc_target/spec/apple_sdk_base.rs
index 03e0c55282e..c7cff17b154 100644
--- a/src/librustc_target/spec/apple_sdk_base.rs
+++ b/src/librustc_target/spec/apple_sdk_base.rs
@@ -49,34 +49,20 @@ pub fn get_sdk_root(sdk_name: &str) -> Result<String, String> {
             // Ignore `SDKROOT` if it's clearly set for the wrong platform.
             "appletvos"
                 if sdkroot.contains("TVSimulator.platform")
-                    || sdkroot.contains("MacOSX.platform") =>
-            {
-                ()
-            }
+                    || sdkroot.contains("MacOSX.platform") => {}
             "appletvsimulator"
-                if sdkroot.contains("TVOS.platform") || sdkroot.contains("MacOSX.platform") =>
-            {
-                ()
-            }
+                if sdkroot.contains("TVOS.platform") || sdkroot.contains("MacOSX.platform") => {}
             "iphoneos"
                 if sdkroot.contains("iPhoneSimulator.platform")
-                    || sdkroot.contains("MacOSX.platform") =>
-            {
-                ()
-            }
+                    || sdkroot.contains("MacOSX.platform") => {}
             "iphonesimulator"
-                if sdkroot.contains("iPhoneOS.platform") || sdkroot.contains("MacOSX.platform") =>
-            {
-                ()
+                if sdkroot.contains("iPhoneOS.platform") || sdkroot.contains("MacOSX.platform") => {
             }
             "macosx10.15"
                 if sdkroot.contains("iPhoneOS.platform")
-                    || sdkroot.contains("iPhoneSimulator.platform") =>
-            {
-                ()
-            }
+                    || sdkroot.contains("iPhoneSimulator.platform") => {}
             // Ignore `SDKROOT` if it's not a valid path.
-            _ if !p.is_absolute() || p == Path::new("/") || !p.exists() => (),
+            _ if !p.is_absolute() || p == Path::new("/") || !p.exists() => {}
             _ => return Ok(sdkroot),
         }
     }
diff --git a/src/librustc_typeck/coherence/builtin.rs b/src/librustc_typeck/coherence/builtin.rs
index e24d9bebf65..d0a87e240da 100644
--- a/src/librustc_typeck/coherence/builtin.rs
+++ b/src/librustc_typeck/coherence/builtin.rs
@@ -178,10 +178,7 @@ fn visit_implementation_of_dispatch_from_dyn(tcx: TyCtxt<'_>, impl_did: DefId) {
             use ty::TyKind::*;
             match (&source.kind, &target.kind) {
                 (&Ref(r_a, _, mutbl_a), Ref(r_b, _, mutbl_b))
-                    if infcx.at(&cause, param_env).eq(r_a, r_b).is_ok() && mutbl_a == *mutbl_b =>
-                {
-                    ()
-                }
+                    if infcx.at(&cause, param_env).eq(r_a, r_b).is_ok() && mutbl_a == *mutbl_b => {}
                 (&RawPtr(tm_a), &RawPtr(tm_b)) if tm_a.mutbl == tm_b.mutbl => (),
                 (&Adt(def_a, substs_a), &Adt(def_b, substs_b))
                     if def_a.is_struct() && def_b.is_struct() =>