Use more Rust features allowed under REPO_MSRV (#6887)

* chore: remove `std::mem::*` imports now unnecessary with `REPO_MSRV`

`std::mem::{size,align}_of{,_val}` was added to `std::prelude` in Rust
1.80; see
[`rust`#123168](rust-lang/rust#123168).

* refactor(benches): s/once_cell::Lazy/std::sync::LazyLock

Weaken our dependence on the `once_cell` crate by using functionality
from `std` instead that was upstreamed from `once_cell`, this time with
what's available in Rust 1.80+.

It's not yet possible to eliminate this dependency entirely, but do what
we can with `REPO_MSRV` for now.

* chore: remove unnecessarily `allow`'d lint rules under `REPO_MSRV`

* chore: migrate easy `allow`s to `expect` under `REPO_MSRV`

Remove or `expect` clear-cut `allow` statements that were easy for me to
figure out.

* chore: `warn` on `clippy::allow_attributes` under `REPO_MSRV`

Author: ErichDonGubler

Cargo.lock

@@ -43,7 +43,6 @@ naga = { workspace = true, features = [
     "wgsl-out",
 ] }
 nanorand.workspace = true
-once_cell.workspace = true
 pollster.workspace = true
 profiling.workspace = true
 rayon.workspace = true

benches/Cargo.toml

@@ -5,7 +5,7 @@ use std::{
 
 use criterion::{criterion_group, Criterion, Throughput};
 use nanorand::{Rng, WyRand};
-use once_cell::sync::Lazy;
+use std::sync::LazyLock;
 
 use crate::DeviceState;
 
@@ -60,7 +60,7 @@ impl BindGroupState {
 }
 
 fn run_bench(ctx: &mut Criterion) {
-    let state = Lazy::new(BindGroupState::new);
+    let state = LazyLock::new(BindGroupState::new);
 
     if !state
         .device_state

benches/benches/bind_groups.rs

@@ -5,8 +5,8 @@ use std::{
 
 use criterion::{criterion_group, Criterion, Throughput};
 use nanorand::{Rng, WyRand};
-use once_cell::sync::Lazy;
 use rayon::iter::{IntoParallelIterator, ParallelIterator};
+use std::sync::LazyLock;
 
 use crate::DeviceState;
 
@@ -424,7 +424,7 @@ impl ComputepassState {
 }
 
 fn run_bench(ctx: &mut Criterion) {
-    let state = Lazy::new(ComputepassState::new);
+    let state = LazyLock::new(ComputepassState::new);
 
     let dispatch_count = dispatch_count();
     let dispatch_count_bindless = dispatch_count_bindless();
@@ -449,7 +449,7 @@ fn run_bench(ctx: &mut Criterion) {
             group.bench_function(
                 format!("{cpasses} computepasses x {dispatch_per_pass} dispatches ({label})"),
                 |b| {
-                    Lazy::force(&state);
+                    LazyLock::force(&state);
 
                     b.iter_custom(|iters| {
                         profiling::scope!("benchmark invocation");
@@ -498,7 +498,7 @@ fn run_bench(ctx: &mut Criterion) {
         group.bench_function(
             format!("{threads} threads x {dispatch_per_pass} dispatch"),
             |b| {
-                Lazy::force(&state);
+                LazyLock::force(&state);
 
                 b.iter_custom(|iters| {
                     profiling::scope!("benchmark invocation");
@@ -538,7 +538,7 @@ fn run_bench(ctx: &mut Criterion) {
     group.throughput(Throughput::Elements(dispatch_count_bindless as _));
 
     group.bench_function(format!("{dispatch_count_bindless} dispatch"), |b| {
-        Lazy::force(&state);
+        LazyLock::force(&state);
 
         b.iter_custom(|iters| {
             profiling::scope!("benchmark invocation");
@@ -579,7 +579,7 @@ fn run_bench(ctx: &mut Criterion) {
             texture_count + storage_texture_count + storage_buffer_count
         ),
         |b| {
-            Lazy::force(&state);
+            LazyLock::force(&state);
 
             b.iter(|| state.device_state.queue.submit([]));
         },

benches/benches/computepass.rs

@@ -5,8 +5,8 @@ use std::{
 
 use criterion::{criterion_group, Criterion, Throughput};
 use nanorand::{Rng, WyRand};
-use once_cell::sync::Lazy;
 use rayon::iter::{IntoParallelIterator, ParallelIterator};
+use std::sync::LazyLock;
 
 use crate::DeviceState;
 
@@ -427,7 +427,7 @@ impl RenderpassState {
 }
 
 fn run_bench(ctx: &mut Criterion) {
-    let state = Lazy::new(RenderpassState::new);
+    let state = LazyLock::new(RenderpassState::new);
 
     let draw_count = draw_count();
     let vertex_buffer_count = draw_count * VERTEX_BUFFERS_PER_DRAW;
@@ -450,7 +450,7 @@ fn run_bench(ctx: &mut Criterion) {
             group.bench_function(
                 format!("{rpasses} renderpasses x {draws_per_pass} draws ({label})"),
                 |b| {
-                    Lazy::force(&state);
+                    LazyLock::force(&state);
 
                     b.iter_custom(|iters| {
                         profiling::scope!("benchmark invocation");
@@ -502,7 +502,7 @@ fn run_bench(ctx: &mut Criterion) {
     for threads in [2, 4, 8] {
         let draws_per_pass = draw_count / threads;
         group.bench_function(format!("{threads} threads x {draws_per_pass} draws"), |b| {
-            Lazy::force(&state);
+            LazyLock::force(&state);
 
             b.iter_custom(|iters| {
                 profiling::scope!("benchmark invocation");
@@ -541,7 +541,7 @@ fn run_bench(ctx: &mut Criterion) {
     group.throughput(Throughput::Elements(draw_count as _));
 
     group.bench_function(format!("{draw_count} draws"), |b| {
-        Lazy::force(&state);
+        LazyLock::force(&state);
 
         b.iter_custom(|iters| {
             profiling::scope!("benchmark invocation");
@@ -577,7 +577,7 @@ fn run_bench(ctx: &mut Criterion) {
             texture_count + vertex_buffer_count
         ),
         |b| {
-            Lazy::force(&state);
+            LazyLock::force(&state);
 
             b.iter(|| state.device_state.queue.submit([]));
         },

benches/benches/renderpass.rs

@@ -1,13 +1,13 @@
 use std::time::{Duration, Instant};
 
 use criterion::{criterion_group, Criterion, Throughput};
-use once_cell::sync::Lazy;
 use rayon::iter::{IntoParallelIterator, ParallelIterator};
+use std::sync::LazyLock;
 
 use crate::DeviceState;
 
 fn run_bench(ctx: &mut Criterion) {
-    let state = Lazy::new(DeviceState::new);
+    let state = LazyLock::new(DeviceState::new);
 
     const RESOURCES_TO_CREATE: usize = 8;
 
@@ -19,7 +19,7 @@ fn run_bench(ctx: &mut Criterion) {
         group.bench_function(
             format!("{threads} threads x {resources_per_thread} resource"),
             |b| {
-                Lazy::force(&state);
+                LazyLock::force(&state);
 
                 b.iter_custom(|iters| {
                     profiling::scope!("benchmark invocation");

benches/benches/resource_creation.rs

@@ -2,7 +2,6 @@
 // adapted from https://github.com/austinEng/webgpu-samples/blob/master/src/examples/computeBoids.ts
 
 use nanorand::{Rng, WyRand};
-use std::mem::size_of;
 use wgpu::util::DeviceExt;
 
 // number of boid particles to simulate

examples/src/boids/mod.rs

@@ -1,6 +1,6 @@
 use bytemuck::{Pod, Zeroable};
 use nanorand::{Rng, WyRand};
-use std::{borrow::Cow, mem::size_of};
+use std::borrow::Cow;
 use wgpu::util::DeviceExt;
 use winit::{
     event::{ElementState, KeyEvent},

examples/src/bunnymark/mod.rs

@@ -1,5 +1,5 @@
 use bytemuck::{Pod, Zeroable};
-use std::{f32::consts, mem::size_of};
+use std::f32::consts;
 use wgpu::util::DeviceExt;
 
 #[repr(C)]

examples/src/cube/mod.rs

@@ -362,8 +362,7 @@ async fn start<E: Example>(title: &str) {
     }
 
     log::info!("Entering event loop...");
-    // On native this is a result, but on wasm it's a unit type.
-    #[allow(clippy::let_unit_value)]
+    #[cfg_attr(target_arch = "wasm32", expect(clippy::let_unit_value))]
     let _ = (event_loop_function)(
         window_loop.event_loop,
         move |event: Event<()>, target: &EventLoopWindowTarget<()>| {