From 3b26b3d1d2d1fc6f660543c210429d8b2b9a3b18 Mon Sep 17 00:00:00 2001
From: klensy <klensy@users.noreply.github.com>
Date: Mon, 21 Aug 2023 15:07:18 +0300
Subject: [PATCH] don't use SnapshotVec in Graph implementation, as it looks
 unused; use Vec instead

---
 .../src/graph/implementation/mod.rs           | 23 ++++---------------
 1 file changed, 4 insertions(+), 19 deletions(-)

diff --git a/compiler/rustc_data_structures/src/graph/implementation/mod.rs b/compiler/rustc_data_structures/src/graph/implementation/mod.rs
index 9ff401c3c7aad..3910c6fa46d81 100644
--- a/compiler/rustc_data_structures/src/graph/implementation/mod.rs
+++ b/compiler/rustc_data_structures/src/graph/implementation/mod.rs
@@ -20,7 +20,6 @@
 //! the field `next_edge`). Each of those fields is an array that should
 //! be indexed by the direction (see the type `Direction`).
 
-use crate::snapshot_vec::{SnapshotVec, SnapshotVecDelegate};
 use rustc_index::bit_set::BitSet;
 use std::fmt::Debug;
 
@@ -28,8 +27,8 @@ use std::fmt::Debug;
 mod tests;
 
 pub struct Graph<N, E> {
-    nodes: SnapshotVec<Node<N>>,
-    edges: SnapshotVec<Edge<E>>,
+    nodes: Vec<Node<N>>,
+    edges: Vec<Edge<E>>,
 }
 
 pub struct Node<N> {
@@ -45,20 +44,6 @@ pub struct Edge<E> {
     pub data: E,
 }
 
-impl<N> SnapshotVecDelegate for Node<N> {
-    type Value = Node<N>;
-    type Undo = ();
-
-    fn reverse(_: &mut Vec<Node<N>>, _: ()) {}
-}
-
-impl<N> SnapshotVecDelegate for Edge<N> {
-    type Value = Edge<N>;
-    type Undo = ();
-
-    fn reverse(_: &mut Vec<Edge<N>>, _: ()) {}
-}
-
 #[derive(Copy, Clone, PartialEq, Debug)]
 pub struct NodeIndex(pub usize);
 
@@ -86,11 +71,11 @@ impl NodeIndex {
 
 impl<N: Debug, E: Debug> Graph<N, E> {
     pub fn new() -> Graph<N, E> {
-        Graph { nodes: SnapshotVec::new(), edges: SnapshotVec::new() }
+        Graph { nodes: Vec::new(), edges: Vec::new() }
     }
 
     pub fn with_capacity(nodes: usize, edges: usize) -> Graph<N, E> {
-        Graph { nodes: SnapshotVec::with_capacity(nodes), edges: SnapshotVec::with_capacity(edges) }
+        Graph { nodes: Vec::with_capacity(nodes), edges: Vec::with_capacity(edges) }
     }
 
     // # Simple accessors