wgpu-sync: remove alloc feature

The project is otherwise not `no_alloc` compatible, and is capable of making a breaking change in the future if desirable.

Co-Authored-By: Kevin Reid <kpreid@switchb.org>

Author: bushrat011899

.github/workflows/ci.yml

@@ -333,7 +333,7 @@ jobs:
           # Check with all compatible features
           cargo --locked clippy --target ${{ matrix.target }} ${{ matrix.extra-flags }} -p wgpu-types --no-default-features --features strict_asserts,fragile-send-sync-non-atomic-wasm,serde,counters
           cargo --locked clippy --target ${{ matrix.target }} ${{ matrix.extra-flags }} -p naga-types --no-default-features --features serialize,deserialize
-          cargo --locked clippy --target ${{ matrix.target }} ${{ matrix.extra-flags }} -p wgpu-sync --no-default-features --features alloc
+          cargo --locked clippy --target ${{ matrix.target }} ${{ matrix.extra-flags }} -p wgpu-sync --no-default-features
           cargo --locked clippy --target ${{ matrix.target }} ${{ matrix.extra-flags }} -p naga --no-default-features --features dot-out,spv-in,spv-out,glsl-out,msl-out,serialize,deserialize,wgsl-in,wgsl-out,hlsl-out
           cargo --locked clippy --target ${{ matrix.target }} ${{ matrix.extra-flags }} -p wgpu-hal --no-default-features --features fragile-send-sync-non-atomic-wasm
           cargo --locked clippy --target ${{ matrix.target }} ${{ matrix.extra-flags }} -p wgpu-core --no-default-features --features api_log_info,resource_log_info,strict_asserts,serde,wgsl,spirv,counters,noop

wgpu-sync/Cargo.toml

@@ -29,11 +29,10 @@ alloc_instead_of_core = "warn"
 
 [features]
 default = ["std"]
-std = ["alloc", "dep:parking_lot", "once_cell/std"]
-alloc = ["once_cell/alloc"]
+std = ["dep:parking_lot", "once_cell/std"]
 
 [dependencies]
 cfg-if.workspace = true
 lock_api = { workspace = true, default-features = false }
 parking_lot = { workspace = true, optional = true }
-once_cell = { workspace = true, default-features = false, features = ["race"] }
+once_cell = { workspace = true, default-features = false, features = ["alloc", "race"] }

wgpu-sync/src/lib.rs

@@ -9,7 +9,6 @@
 
 //! Provides [`Mutex`] and [`RwLock`] types with an appropriate implementation.
 
-#[cfg(feature = "alloc")]
 extern crate alloc;
 #[cfg(feature = "std")]
 extern crate std;
@@ -26,9 +25,7 @@ pub use rwlock::RawRwLock;
 #[cfg(feature = "std")]
 pub use parking_lot::{Condvar, Mutex as CondvarMutex};
 
-#[cfg(feature = "alloc")]
-pub use once_cell::race::OnceBox;
-pub use once_cell::race::{OnceBool, OnceNonZeroUsize, OnceRef};
+pub use once_cell::race::{OnceBool, OnceBox, OnceNonZeroUsize, OnceRef};
 
 cfg_if::cfg_if! {
     if #[cfg(feature = "std")] {