From 5c3ae32ab18c689eb0403c0012eb72113d8bfd83 Mon Sep 17 00:00:00 2001
From: BD103 <59022059+BD103@users.noreply.github.com>
Date: Wed, 10 Apr 2024 16:16:48 -0400
Subject: [PATCH] Enable `clippy::ref_as_ptr` (#12918)

# Objective

-
[`clippy::ref_as_ptr`](https://rust-lang.github.io/rust-clippy/master/index.html#/ref_as_ptr)
prevents you from directly casting references to pointers, requiring you
to use `std::ptr::from_ref` instead. This prevents you from accidentally
converting an immutable reference into a mutable pointer (`&x as *mut
T`).
- Follow up to #11818, now that our [`rust-version` is
1.77](https://github.com/bevyengine/bevy/blob/11817f4ba4cca8e956c50f6d919e38f601ecc5cf/Cargo.toml#L14).

## Solution

- Enable lint and fix all warnings.
---
 Cargo.toml                              | 3 +--
 crates/bevy_mikktspace/src/generated.rs | 6 +++---
 crates/bevy_render/src/mesh/mod.rs      | 4 +++-
 3 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 35aa37f373ae9..391cd213472b4 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -41,8 +41,7 @@ semicolon_if_nothing_returned = "warn"
 
 ptr_as_ptr = "warn"
 ptr_cast_constness = "warn"
-#TODO(rust 1.77): enable `ref_as_ptr`
-# ref_as_ptr = "warn"
+ref_as_ptr = "warn"
 
 [workspace.lints.rust]
 unsafe_op_in_unsafe_fn = "warn"
diff --git a/crates/bevy_mikktspace/src/generated.rs b/crates/bevy_mikktspace/src/generated.rs
index 91c697b3299d9..592e1679e5168 100644
--- a/crates/bevy_mikktspace/src/generated.rs
+++ b/crates/bevy_mikktspace/src/generated.rs
@@ -45,7 +45,7 @@
     unsafe_code
 )]
 
-use std::ptr::null_mut;
+use std::ptr::{self, null_mut};
 
 use glam::Vec3;
 
@@ -830,7 +830,7 @@ unsafe fn Build4RuleGroups(
                 let mut neigh_indexR: i32 = 0;
                 let vert_index: i32 = *piTriListIn.offset((f * 3i32 + i) as isize);
                 let ref mut fresh2 = (*pTriInfos.offset(f as isize)).AssignedGroup[i as usize];
-                *fresh2 = &mut *pGroups.offset(iNrActiveGroups as isize) as *mut SGroup;
+                *fresh2 = ptr::from_mut(&mut *pGroups.offset(iNrActiveGroups as isize));
                 (*(*pTriInfos.offset(f as isize)).AssignedGroup[i as usize])
                     .iVertexRepresentative = vert_index;
                 (*(*pTriInfos.offset(f as isize)).AssignedGroup[i as usize]).bOrientPreservering =
@@ -838,7 +838,7 @@ unsafe fn Build4RuleGroups(
                 (*(*pTriInfos.offset(f as isize)).AssignedGroup[i as usize]).iNrFaces = 0i32;
                 let ref mut fresh3 =
                     (*(*pTriInfos.offset(f as isize)).AssignedGroup[i as usize]).pFaceIndices;
-                *fresh3 = &mut *piGroupTrianglesBuffer.offset(iOffset as isize) as *mut i32;
+                *fresh3 = ptr::from_mut(&mut *piGroupTrianglesBuffer.offset(iOffset as isize));
                 iNrActiveGroups += 1;
                 AddTriToGroup((*pTriInfos.offset(f as isize)).AssignedGroup[i as usize], f);
                 bOrPre = if (*pTriInfos.offset(f as isize)).iFlag & 8i32 != 0i32 {
diff --git a/crates/bevy_render/src/mesh/mod.rs b/crates/bevy_render/src/mesh/mod.rs
index cbac3705ddcd5..df33640716496 100644
--- a/crates/bevy_render/src/mesh/mod.rs
+++ b/crates/bevy_render/src/mesh/mod.rs
@@ -80,6 +80,8 @@ impl Eq for MeshVertexBufferLayoutRef {}
 
 impl Hash for MeshVertexBufferLayoutRef {
     fn hash<H: Hasher>(&self, state: &mut H) {
-        (&*self.0 as *const MeshVertexBufferLayout as usize).hash(state);
+        // Hash the address of the underlying data, so two layouts that share the same
+        // `MeshVertexBufferLayout` will have the same hash.
+        (Arc::as_ptr(&self.0) as usize).hash(state);
     }
 }