Replace &Vec<_>s with &[_]s

compiler/rustc_middle/src/middle/region.rs

@@ -16,6 +16,7 @@ use rustc_query_system::ich::StableHashingContext;
 use rustc_span::{Span, DUMMY_SP};
 
 use std::fmt;
+use std::ops::Deref;
 
 /// Represents a statically-describable scope that can be used to
 /// bound the lifetime/region for values.
@@ -407,8 +408,8 @@ impl ScopeTree {
 
     /// Checks whether the given scope contains a `yield`. If so,
     /// returns `Some(YieldData)`. If not, returns `None`.
-    pub fn yield_in_scope(&self, scope: Scope) -> Option<&Vec<YieldData>> {
-        self.yield_in_scope.get(&scope)
+    pub fn yield_in_scope(&self, scope: Scope) -> Option<&[YieldData]> {
+        self.yield_in_scope.get(&scope).map(Deref::deref)
     }
 
     /// Gives the number of expressions visited in a body.

compiler/rustc_middle/src/mir/traversal.rs

@@ -310,7 +310,7 @@ pub fn reachable_as_bitset<'tcx>(body: &Body<'tcx>) -> BitSet<BasicBlock> {
 #[derive(Clone)]
 pub struct ReversePostorderIter<'a, 'tcx> {
     body: &'a Body<'tcx>,
-    blocks: &'a Vec<BasicBlock>,
+    blocks: &'a [BasicBlock],
     idx: usize,
 }
 
@@ -358,9 +358,9 @@ impl PostorderCache {
         self.cache = OnceCell::new();
     }
 
-    /// Returns the &Vec<BasicBlocks> represents the postorder graph for this MIR.
+    /// Returns the `&[BasicBlocks]` represents the postorder graph for this MIR.
     #[inline]
-    pub(super) fn compute(&self, body: &Body<'_>) -> &Vec<BasicBlock> {
+    pub(super) fn compute(&self, body: &Body<'_>) -> &[BasicBlock] {
         self.cache.get_or_init(|| Postorder::new(body, START_BLOCK).map(|(bb, _)| bb).collect())
     }
 }

compiler/rustc_middle/src/ty/sty.rs

@@ -1032,6 +1032,13 @@ impl<'tcx, T> Binder<'tcx, T> {
         Binder(&self.0, self.1)
     }
 
+    pub fn as_deref(&self) -> Binder<'tcx, &T::Target>
+    where
+        T: Deref,
+    {
+        Binder(&self.0, self.1)
+    }
+
     pub fn map_bound_ref_unchecked<F, U>(&self, f: F) -> Binder<'tcx, U>
     where
         F: FnOnce(&T) -> U,