Fix compiler warnings.

src/accel/bvh4.rs

@@ -56,7 +56,7 @@ impl<'a> BVH4<'a> {
         } else {
             let base = BVHBase::from_objects(objects, objects_per_leaf, bounder);
 
-            let mut root = unsafe { arena.alloc_uninitialized::<BVH4Node>() };
+            let root = unsafe { arena.alloc_uninitialized::<BVH4Node>() };
             BVH4::construct_from_base(arena, &base, base.root_node_index(), root);
             BVH4 {
                 root: Some(root),

src/accel/light_tree.rs

@@ -73,7 +73,7 @@ impl<'a> LightTree<'a> {
             let mut builder = LightTreeBuilder::new();
             builder.recursive_build(0, 0, objects, &info_getter);
 
-            let mut root = unsafe { arena.alloc_uninitialized::<Node>() };
+            let root = unsafe { arena.alloc_uninitialized::<Node>() };
             LightTree::construct_from_builder(arena, &builder, builder.root_node_index(), root);
 
             LightTree {
@@ -105,7 +105,7 @@ impl<'a> LightTree<'a> {
             let bounds = arena.copy_slice(&base.bounds[bounds_range.0..bounds_range.1]);
 
             let child_count = base.node_child_count(node_index);
-            let mut children = unsafe { arena.alloc_array_uninitialized::<Node>(child_count) };
+            let children = unsafe { arena.alloc_array_uninitialized::<Node>(child_count) };
             for i in 0..child_count {
                 LightTree::construct_from_builder(
                     arena,

src/surface/triangle_mesh.rs

@@ -67,7 +67,7 @@ impl<'a> TriangleMesh<'a> {
         };
 
         // Copy triangle vertex indices over, appending the triangle index itself to the tuple
-        let mut indices = {
+        let indices = {
             let mut indices = unsafe { arena.alloc_array_uninitialized(tri_indices.len()) };
             for (i, tri_i) in tri_indices.iter().enumerate() {
                 indices[i] = (tri_i.0 as u32, tri_i.2 as u32, tri_i.1 as u32, i as u32);

src/tracer.rs

@@ -114,7 +114,7 @@ impl<'a> TracerInner<'a> {
                             &mut [],
                         ]
                     };
-                    let mut ray_sets = if inst.transform_indices.is_some() {
+                    let ray_sets = if inst.transform_indices.is_some() {
                         &mut tmp[..]
                     } else {
                         &mut tmp[..1]

sub_crates/mem_arena/src/lib.rs

@@ -105,7 +105,7 @@ impl MemArena {
 
     /// Allocates memory for and initializes a type T, returning a mutable reference to it.
     pub fn alloc<'a, T: Copy>(&'a self, value: T) -> &'a mut T {
-        let mut memory = unsafe { self.alloc_uninitialized() };
+        let memory = unsafe { self.alloc_uninitialized() };
         *memory = value;
         memory
     }
@@ -115,7 +115,7 @@ impl MemArena {
     /// Additionally, the allocation will be made with the given byte alignment or
     /// the type's inherent alignment, whichever is greater.
     pub fn alloc_with_alignment<'a, T: Copy>(&'a self, value: T, align: usize) -> &'a mut T {
-        let mut memory = unsafe { self.alloc_uninitialized_with_alignment(align) };
+        let memory = unsafe { self.alloc_uninitialized_with_alignment(align) };
         *memory = value;
         memory
     }