Use `&IndexSlice` instead of `&IndexVec` where possible

All the same reasons as for `[T]`: more general, less pointer chasing, and `&mut IndexSlice` emphasizes that it doesn't change *length*.

2 files changed, 9 insertions, 9 deletions

diff --git a/compiler/rustc_mir_dataflow/src/move_paths/mod.rs b/compiler/rustc_mir_dataflow/src/move_paths/mod.rs
index 5f22a418de8..257a42cddc8 100644
--- a/compiler/rustc_mir_dataflow/src/move_paths/mod.rs
+++ b/compiler/rustc_mir_dataflow/src/move_paths/mod.rs
@@ -1,6 +1,6 @@
 use crate::move_paths::builder::MoveDat;
 use rustc_data_structures::fx::FxHashMap;
-use rustc_index::vec::IndexVec;
+use rustc_index::vec::{IndexSlice, IndexVec};
 use rustc_middle::mir::*;
 use rustc_middle::ty::{ParamEnv, Ty, TyCtxt};
 use rustc_span::Span;
@@ -64,7 +64,7 @@ impl<'tcx> MovePath<'tcx> {
     /// Returns an iterator over the parents of `self`.
     pub fn parents<'a>(
         &self,
-        move_paths: &'a IndexVec<MovePathIndex, MovePath<'tcx>>,
+        move_paths: &'a IndexSlice<MovePathIndex, MovePath<'tcx>>,
     ) -> impl 'a + Iterator<Item = (MovePathIndex, &'a MovePath<'tcx>)> {
         let first = self.parent.map(|mpi| (mpi, &move_paths[mpi]));
         MovePathLinearIter {
@@ -78,7 +78,7 @@ impl<'tcx> MovePath<'tcx> {
     /// Returns an iterator over the immediate children of `self`.
     pub fn children<'a>(
         &self,
-        move_paths: &'a IndexVec<MovePathIndex, MovePath<'tcx>>,
+        move_paths: &'a IndexSlice<MovePathIndex, MovePath<'tcx>>,
     ) -> impl 'a + Iterator<Item = (MovePathIndex, &'a MovePath<'tcx>)> {
         let first = self.first_child.map(|mpi| (mpi, &move_paths[mpi]));
         MovePathLinearIter {
@@ -95,7 +95,7 @@ impl<'tcx> MovePath<'tcx> {
     /// `f` will **not** be called on `self`.
     pub fn find_descendant(
         &self,
-        move_paths: &IndexVec<MovePathIndex, MovePath<'_>>,
+        move_paths: &IndexSlice<MovePathIndex, MovePath<'_>>,
         f: impl Fn(MovePathIndex) -> bool,
     ) -> Option<MovePathIndex> {
         let mut todo = if let Some(child) = self.first_child {
diff --git a/compiler/rustc_mir_dataflow/src/value_analysis.rs b/compiler/rustc_mir_dataflow/src/value_analysis.rs
index 63e553bec53..33a15a8d224 100644
--- a/compiler/rustc_mir_dataflow/src/value_analysis.rs
+++ b/compiler/rustc_mir_dataflow/src/value_analysis.rs
@@ -36,7 +36,7 @@ use std::fmt::{Debug, Formatter};
 
 use rustc_data_structures::fx::FxHashMap;
 use rustc_index::bit_set::BitSet;
-use rustc_index::vec::IndexVec;
+use rustc_index::vec::{IndexSlice, IndexVec};
 use rustc_middle::mir::visit::{MutatingUseContext, PlaceContext, Visitor};
 use rustc_middle::mir::*;
 use rustc_middle::ty::{self, Ty, TyCtxt};
@@ -1028,8 +1028,8 @@ where
 fn debug_with_context_rec<V: Debug + Eq>(
     place: PlaceIndex,
     place_str: &str,
-    new: &IndexVec<ValueIndex, V>,
-    old: Option<&IndexVec<ValueIndex, V>>,
+    new: &IndexSlice<ValueIndex, V>,
+    old: Option<&IndexSlice<ValueIndex, V>>,
     map: &Map,
     f: &mut Formatter<'_>,
 ) -> std::fmt::Result {
@@ -1069,8 +1069,8 @@ fn debug_with_context_rec<V: Debug + Eq>(
 }
 
 fn debug_with_context<V: Debug + Eq>(
-    new: &IndexVec<ValueIndex, V>,
-    old: Option<&IndexVec<ValueIndex, V>>,
+    new: &IndexSlice<ValueIndex, V>,
+    old: Option<&IndexSlice<ValueIndex, V>>,
     map: &Map,
     f: &mut Formatter<'_>,
 ) -> std::fmt::Result {