4 files changed, 6 insertions, 7 deletions
diff --git a/compiler/rustc_middle/src/hir/map/mod.rs b/compiler/rustc_middle/src/hir/map/mod.rs
index 6641606f1e8..06bb1347dc1 100644
--- a/compiler/rustc_middle/src/hir/map/mod.rs
+++ b/compiler/rustc_middle/src/hir/map/mod.rs
@@ -815,7 +815,7 @@ impl<'hir> Map<'hir> {
     /// Given a node ID, gets a list of attributes associated with the AST
     /// corresponding to the node-ID.
     pub fn attrs(&self, id: HirId) -> &'hir [ast::Attribute] {
-        let attrs = self.find_entry(id).map(|entry| match entry.node {
+        self.find_entry(id).map_or(&[], |entry| match entry.node {
             Node::Param(a) => &a.attrs[..],
             Node::Local(l) => &l.attrs[..],
             Node::Item(i) => &i.attrs[..],
@@ -842,8 +842,7 @@ impl<'hir> Map<'hir> {
             | Node::Block(..)
             | Node::Lifetime(..)
             | Node::Visibility(..) => &[],
-        });
-        attrs.unwrap_or(&[])
+        })
     }
 
     /// Gets the span of the definition of the specified HIR node.
diff --git a/compiler/rustc_middle/src/ty/consts/kind.rs b/compiler/rustc_middle/src/ty/consts/kind.rs
index ecf2837b3e4..a2638d8bdda 100644
--- a/compiler/rustc_middle/src/ty/consts/kind.rs
+++ b/compiler/rustc_middle/src/ty/consts/kind.rs
@@ -82,7 +82,7 @@ impl<'tcx> ConstKind<'tcx> {
     /// Tries to evaluate the constant if it is `Unevaluated`. If that doesn't succeed, return the
     /// unevaluated constant.
     pub fn eval(self, tcx: TyCtxt<'tcx>, param_env: ParamEnv<'tcx>) -> Self {
-        self.try_eval(tcx, param_env).and_then(Result::ok).map(ConstKind::Value).unwrap_or(self)
+        self.try_eval(tcx, param_env).and_then(Result::ok).map_or(self, ConstKind::Value)
     }
 
     #[inline]
diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs
index 3540f0f06b6..c3ad4c1c126 100644
--- a/compiler/rustc_middle/src/ty/context.rs
+++ b/compiler/rustc_middle/src/ty/context.rs
@@ -1338,7 +1338,7 @@ impl<'tcx> TyCtxt<'tcx> {
     }
 
     pub fn serialize_query_result_cache(self, encoder: &mut FileEncoder) -> FileEncodeResult {
-        self.queries.on_disk_cache.as_ref().map(|c| c.serialize(self, encoder)).unwrap_or(Ok(()))
+        self.queries.on_disk_cache.as_ref().map_or(Ok(()), |c| c.serialize(self, encoder))
     }
 
     /// If `true`, we should use the MIR-based borrowck, but also
@@ -2601,7 +2601,7 @@ impl<'tcx> TyCtxt<'tcx> {
     }
 
     pub fn is_late_bound(self, id: HirId) -> bool {
-        self.is_late_bound_map(id.owner).map(|set| set.contains(&id.local_id)).unwrap_or(false)
+        self.is_late_bound_map(id.owner).map_or(false, |set| set.contains(&id.local_id))
     }
 
     pub fn object_lifetime_defaults(self, id: HirId) -> Option<&'tcx [ObjectLifetimeDefault]> {
diff --git a/compiler/rustc_middle/src/ty/instance.rs b/compiler/rustc_middle/src/ty/instance.rs
index 413c9cca589..6ca5dcc532d 100644
--- a/compiler/rustc_middle/src/ty/instance.rs
+++ b/compiler/rustc_middle/src/ty/instance.rs
@@ -535,7 +535,7 @@ fn polymorphize<'tcx>(
     } else {
         None
     };
-    let has_upvars = upvars_ty.map(|ty| ty.tuple_fields().count() > 0).unwrap_or(false);
+    let has_upvars = upvars_ty.map_or(false, |ty| ty.tuple_fields().count() > 0);
     debug!("polymorphize: upvars_ty={:?} has_upvars={:?}", upvars_ty, has_upvars);
 
     struct PolymorphizationFolder<'tcx> {