Use () instead of PhantomData as IdentityManager's Input type. (#2972)

* Use () instead of PhantomData as IdentityManager's Input type. PhantomData suggests that there's some sort of persuasion required for lifetime variance inference or other sorts of arcana, but it doesn't seem to be necessary at all. `()` works just fine.
2026-04-22 03:02:01 -04:00 · 2022-09-02 15:37:21 -07:00
parent ee7fd47ecb
commit 701564da8c
12 changed files with 57 additions and 63 deletions
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -86,7 +86,8 @@ the same every time it is rendered, we now warn if it is missing.
 - Added downlevel restriction error message for `InvalidFormatUsages` error by @Seamooo in [#2886](https://github.com/gfx-rs/wgpu/pull/2886)
 - Add warning when using CompareFunction::*Equal with vertex shader that is missing @invariant tag by @cwfitzgerald in [#2887](https://github.com/gfx-rs/wgpu/pull/2887)
 - Update Winit to version 0.27 and raw-window-handle to 0.5 by @wyatt-herkamp in  [#2918](https://github.com/gfx-rs/wgpu/pull/2918)
- Address Clippy 0.1.63 complaints. By @jimb in [#2977](https://github.com/gfx-rs/wgpu/pull/2977)
+- Address Clippy 0.1.63 complaints. By @jimblandy in [#2977](https://github.com/gfx-rs/wgpu/pull/2977)
+- Don't use `PhantomData` for `IdentityManager`'s `Input` type. By @jimblandy in [#2972](https://github.com/gfx-rs/wgpu/pull/2972)
 #### Metal
 - Extract the generic code into `get_metal_layer` by @jinleili in [#2826](https://github.com/gfx-rs/wgpu/pull/2826)

--- a/deno_webgpu/src/binding.rs
+++ b/deno_webgpu/src/binding.rs
@@ -192,7 +192,7 @@ pub fn op_webgpu_create_bind_group_layout(
    gfx_put!(device => instance.device_create_bind_group_layout(
    device,
    &descriptor,
-    std::marker::PhantomData
+    ()
  ) => state, WebGpuBindGroupLayout)
 }

@@ -226,7 +226,7 @@ pub fn op_webgpu_create_pipeline_layout(
    gfx_put!(device => instance.device_create_pipeline_layout(
    device,
    &descriptor,
-    std::marker::PhantomData
+    ()
  ) => state, super::pipeline::WebGpuPipelineLayout)
 }

@@ -304,6 +304,6 @@ pub fn op_webgpu_create_bind_group(
    gfx_put!(device => instance.device_create_bind_group(
    device,
    &descriptor,
-    std::marker::PhantomData
+    ()
  ) => state, WebGpuBindGroup)
 }
--- a/deno_webgpu/src/buffer.rs
+++ b/deno_webgpu/src/buffer.rs
@@ -57,7 +57,7 @@ pub fn op_webgpu_create_buffer(
    gfx_put!(device => instance.device_create_buffer(
    device,
    &descriptor,
-    std::marker::PhantomData
+    ()
  ) => state, WebGpuBuffer)
 }

--- a/deno_webgpu/src/bundle.rs
+++ b/deno_webgpu/src/bundle.rs
@@ -104,7 +104,7 @@ pub fn op_webgpu_render_bundle_encoder_finish(
    &wgpu_core::command::RenderBundleDescriptor {
      label: label.map(Cow::from),
    },
-    std::marker::PhantomData
+    ()
  ) => state, WebGpuRenderBundle)
 }

--- a/deno_webgpu/src/command_encoder.rs
+++ b/deno_webgpu/src/command_encoder.rs
@@ -45,7 +45,7 @@ pub fn op_webgpu_create_command_encoder(
    gfx_put!(device => instance.device_create_command_encoder(
    device,
    &descriptor,
-    std::marker::PhantomData
+    ()
  ) => state, WebGpuCommandEncoder)
 }

--- a/deno_webgpu/src/lib.rs
+++ b/deno_webgpu/src/lib.rs
@@ -250,7 +250,7 @@ pub async fn op_webgpu_request_adapter(
    };
    let res = instance.request_adapter(
        &descriptor,
-        wgpu_core::instance::AdapterInputs::Mask(backends, |_| std::marker::PhantomData),
+        wgpu_core::instance::AdapterInputs::Mask(backends, |_| ()),
    );

    let adapter = match res {
@@ -413,7 +413,7 @@ pub async fn op_webgpu_request_device(
      adapter,
      &descriptor,
      std::env::var("DENO_WEBGPU_TRACE").ok().as_ref().map(std::path::Path::new),
-      std::marker::PhantomData
+      ()
    ));
    if let Some(err) = maybe_err {
        return Err(DomExceptionOperationError::new(&err.to_string()).into());
@@ -536,7 +536,7 @@ pub fn op_webgpu_create_query_set(
    gfx_put!(device => instance.device_create_query_set(
    device,
    &descriptor,
-    std::marker::PhantomData
+    ()
  ) => state, WebGpuQuerySet)
 }

--- a/deno_webgpu/src/pipeline.rs
+++ b/deno_webgpu/src/pipeline.rs
@@ -95,8 +95,8 @@ pub fn op_webgpu_create_compute_pipeline(
        GPUPipelineLayoutOrGPUAutoLayoutMode::Layout(_) => None,
        GPUPipelineLayoutOrGPUAutoLayoutMode::Auto(GPUAutoLayoutMode::Auto) => {
            Some(wgpu_core::device::ImplicitPipelineIds {
-                root_id: std::marker::PhantomData,
-                group_ids: &[std::marker::PhantomData; MAX_BIND_GROUPS],
+                root_id: (),
+                group_ids: &[(); MAX_BIND_GROUPS],
            })
        }
    };
@@ -104,7 +104,7 @@ pub fn op_webgpu_create_compute_pipeline(
    let (compute_pipeline, maybe_err) = gfx_select!(device => instance.device_create_compute_pipeline(
      device,
      &descriptor,
-      std::marker::PhantomData,
+      (),
      implicit_pipelines
    ));

@@ -135,7 +135,7 @@ pub fn op_webgpu_compute_pipeline_get_bind_group_layout(
        .get::<WebGpuComputePipeline>(compute_pipeline_rid)?;
    let compute_pipeline = compute_pipeline_resource.0;

-    let (bind_group_layout, maybe_err) = gfx_select!(compute_pipeline => instance.compute_pipeline_get_bind_group_layout(compute_pipeline, index, std::marker::PhantomData));
+    let (bind_group_layout, maybe_err) = gfx_select!(compute_pipeline => instance.compute_pipeline_get_bind_group_layout(compute_pipeline, index, ()));

    let label =
        gfx_select!(bind_group_layout => instance.bind_group_layout_label(bind_group_layout));
@@ -364,8 +364,8 @@ pub fn op_webgpu_create_render_pipeline(
        GPUPipelineLayoutOrGPUAutoLayoutMode::Layout(_) => None,
        GPUPipelineLayoutOrGPUAutoLayoutMode::Auto(GPUAutoLayoutMode::Auto) => {
            Some(wgpu_core::device::ImplicitPipelineIds {
-                root_id: std::marker::PhantomData,
-                group_ids: &[std::marker::PhantomData; MAX_BIND_GROUPS],
+                root_id: (),
+                group_ids: &[(); MAX_BIND_GROUPS],
            })
        }
    };
@@ -373,7 +373,7 @@ pub fn op_webgpu_create_render_pipeline(
    let (render_pipeline, maybe_err) = gfx_select!(device => instance.device_create_render_pipeline(
      device,
      &descriptor,
-      std::marker::PhantomData,
+      (),
      implicit_pipelines
    ));

@@ -396,7 +396,7 @@ pub fn op_webgpu_render_pipeline_get_bind_group_layout(
        .get::<WebGpuRenderPipeline>(render_pipeline_rid)?;
    let render_pipeline = render_pipeline_resource.0;

-    let (bind_group_layout, maybe_err) = gfx_select!(render_pipeline => instance.render_pipeline_get_bind_group_layout(render_pipeline, index, std::marker::PhantomData));
+    let (bind_group_layout, maybe_err) = gfx_select!(render_pipeline => instance.render_pipeline_get_bind_group_layout(render_pipeline, index, ()));

    let label =
        gfx_select!(bind_group_layout => instance.bind_group_layout_label(bind_group_layout));
--- a/deno_webgpu/src/sampler.rs
+++ b/deno_webgpu/src/sampler.rs
@@ -65,6 +65,6 @@ pub fn op_webgpu_create_sampler(
    gfx_put!(device => instance.device_create_sampler(
    device,
    &descriptor,
-    std::marker::PhantomData
+    ()
  ) => state, WebGpuSampler)
 }
--- a/deno_webgpu/src/shader.rs
+++ b/deno_webgpu/src/shader.rs
@@ -40,6 +40,6 @@ pub fn op_webgpu_create_shader_module(
    device,
    &descriptor,
    source,
-    std::marker::PhantomData
+    ()
  ) => state, WebGpuShaderModule)
 }
--- a/deno_webgpu/src/texture.rs
+++ b/deno_webgpu/src/texture.rs
@@ -60,7 +60,7 @@ pub fn op_webgpu_create_texture(
    gfx_put!(device => instance.device_create_texture(
    device,
    &descriptor,
-    std::marker::PhantomData
+    ()
  ) => state, WebGpuTexture)
 }

@@ -105,6 +105,6 @@ pub fn op_webgpu_create_texture_view(
    gfx_put!(texture => instance.texture_create_view(
    texture,
    &descriptor,
-    std::marker::PhantomData
+    ()
  ) => state, WebGpuTextureView)
 }
--- a/wgpu-core/src/hub.rs
+++ b/wgpu-core/src/hub.rs
@@ -607,7 +607,7 @@ pub trait IdentityHandler<I>: Debug {
 }

 impl<I: id::TypedId + Debug> IdentityHandler<I> for Mutex<IdentityManager> {
-    type Input = PhantomData<I>;
+    type Input = ();
    fn process(&self, _id: Self::Input, backend: Backend) -> I {
        self.lock().alloc(backend)
    }
--- a/wgpu/src/backend/direct.rs
+++ b/wgpu/src/backend/direct.rs
@@ -15,7 +15,6 @@ use std::{
    error::Error,
    fmt,
    future::{ready, Ready},
-    marker::PhantomData,
    ops::Range,
    slice,
    sync::Arc,
@@ -69,9 +68,7 @@ impl Context {
    #[cfg(any(not(target_arch = "wasm32"), feature = "emscripten"))]
    pub fn enumerate_adapters(&self, backends: wgt::Backends) -> Vec<wgc::id::AdapterId> {
        self.0
-            .enumerate_adapters(wgc::instance::AdapterInputs::Mask(backends, |_| {
-                PhantomData
-            }))
+            .enumerate_adapters(wgc::instance::AdapterInputs::Mask(backends, |_| ()))
    }

    #[cfg(any(not(target_arch = "wasm32"), feature = "emscripten"))]
@@ -79,7 +76,7 @@ impl Context {
        &self,
        hal_adapter: hal::ExposedAdapter<A>,
    ) -> wgc::id::AdapterId {
-        self.0.create_adapter_from_hal(hal_adapter, PhantomData)
+        self.0.create_adapter_from_hal(hal_adapter, ())
    }

    pub unsafe fn adapter_as_hal<A: wgc::hub::HalApi, F: FnOnce(Option<&A::Adapter>) -> R, R>(
@@ -105,7 +102,7 @@ impl Context {
            hal_device,
            &desc.map_label(|l| l.map(Borrowed)),
            trace_dir,
-            PhantomData,
+            (),
        );
        if let Some(err) = error {
            self.handle_error_fatal(err, "Adapter::create_device_from_hal");
@@ -130,7 +127,7 @@ impl Context {
            hal_texture,
            device.id,
            &desc.map_label(|l| l.map(Borrowed)),
-            PhantomData,
+            (),
        );
        if let Some(cause) = error {
            self.handle_error(
@@ -177,7 +174,7 @@ impl Context {
        self: &Arc<Self>,
        layer: *mut std::ffi::c_void,
    ) -> crate::Surface {
-        let id = self.0.instance_create_surface_metal(layer, PhantomData);
+        let id = self.0.instance_create_surface_metal(layer, ());
        crate::Surface {
            context: Arc::clone(self),
            id: Surface {
@@ -192,7 +189,7 @@ impl Context {
        self: &Arc<Self>,
        canvas: &web_sys::HtmlCanvasElement,
    ) -> Surface {
-        let id = self.0.create_surface_webgl_canvas(canvas, PhantomData);
+        let id = self.0.create_surface_webgl_canvas(canvas, ());
        Surface {
            id,
            configured_device: Mutex::default(),
@@ -204,9 +201,7 @@ impl Context {
        self: &Arc<Self>,
        canvas: &web_sys::OffscreenCanvas,
    ) -> Surface {
-        let id = self
-            .0
-            .create_surface_webgl_offscreen_canvas(canvas, PhantomData);
+        let id = self.0.create_surface_webgl_offscreen_canvas(canvas, ());
        Surface {
            id,
            configured_device: Mutex::default(),
@@ -218,9 +213,7 @@ impl Context {
        self: &Arc<Self>,
        visual: *mut std::ffi::c_void,
    ) -> crate::Surface {
-        let id = self
-            .0
-            .instance_create_surface_from_visual(visual, PhantomData);
+        let id = self.0.instance_create_surface_from_visual(visual, ());
        crate::Surface {
            context: Arc::clone(self),
            id: Surface {
@@ -853,7 +846,7 @@ impl crate::Context for Context {
        handle: &(impl raw_window_handle::HasRawWindowHandle + raw_window_handle::HasRawDisplayHandle),
    ) -> Self::SurfaceId {
        Surface {
-            id: self.0.instance_create_surface(handle, PhantomData),
+            id: self.0.instance_create_surface(handle, ()),
            configured_device: Mutex::new(None),
        }
    }
@@ -868,7 +861,7 @@ impl crate::Context for Context {
                force_fallback_adapter: options.force_fallback_adapter,
                compatible_surface: options.compatible_surface.map(|surface| surface.id.id),
            },
-            wgc::instance::AdapterInputs::Mask(wgt::Backends::all(), |_| PhantomData),
+            wgc::instance::AdapterInputs::Mask(wgt::Backends::all(), |_| ()),
        );
        ready(id.ok())
    }
@@ -892,7 +885,7 @@ impl crate::Context for Context {
            *adapter,
            &desc.map_label(|l| l.map(Borrowed)),
            trace_dir,
-            PhantomData
+            ()
        ));
        if let Some(err) = error {
            log::error!("Error in Adapter::request_device: {}", err);
@@ -1022,7 +1015,7 @@ impl crate::Context for Context {
            .lock()
            .expect("Surface was not configured?");
        match wgc::gfx_select!(
-            device_id => global.surface_get_current_texture(surface.id, PhantomData)
+            device_id => global.surface_get_current_texture(surface.id, ())
        ) {
            Ok(wgc::present::SurfaceOutput { status, texture_id }) => (
                texture_id.map(|id| Texture {
@@ -1127,7 +1120,7 @@ impl crate::Context for Context {
            ShaderSource::Naga(module) => wgc::pipeline::ShaderModuleSource::Naga(module),
        };
        let (id, error) = wgc::gfx_select!(
-            device.id => global.device_create_shader_module(device.id, &descriptor, source, PhantomData)
+            device.id => global.device_create_shader_module(device.id, &descriptor, source, ())
        );
        if let Some(cause) = error {
            self.handle_error(
@@ -1154,7 +1147,7 @@ impl crate::Context for Context {
            shader_bound_checks: wgt::ShaderBoundChecks::unchecked(),
        };
        let (id, error) = wgc::gfx_select!(
-            device.id => global.device_create_shader_module_spirv(device.id, &descriptor, Borrowed(&desc.source), PhantomData)
+            device.id => global.device_create_shader_module_spirv(device.id, &descriptor, Borrowed(&desc.source), ())
        );
        if let Some(cause) = error {
            self.handle_error(
@@ -1179,7 +1172,7 @@ impl crate::Context for Context {
            entries: Borrowed(desc.entries),
        };
        let (id, error) = wgc::gfx_select!(
-            device.id => global.device_create_bind_group_layout(device.id, &descriptor, PhantomData)
+            device.id => global.device_create_bind_group_layout(device.id, &descriptor, ())
        );
        if let Some(cause) = error {
            self.handle_error(
@@ -1280,7 +1273,7 @@ impl crate::Context for Context {
        let (id, error) = wgc::gfx_select!(device.id => global.device_create_bind_group(
            device.id,
            &descriptor,
-            PhantomData
+            ()
        ));
        if let Some(cause) = error {
            self.handle_error(
@@ -1323,7 +1316,7 @@ impl crate::Context for Context {
        let (id, error) = wgc::gfx_select!(device.id => global.device_create_pipeline_layout(
            device.id,
            &descriptor,
-            PhantomData
+            ()
        ));
        if let Some(cause) = error {
            self.handle_error(
@@ -1358,8 +1351,8 @@ impl crate::Context for Context {
        let implicit_pipeline_ids = match desc.layout {
            Some(_) => None,
            None => Some(wgc::device::ImplicitPipelineIds {
-                root_id: PhantomData,
-                group_ids: &[PhantomData; wgc::MAX_BIND_GROUPS],
+                root_id: (),
+                group_ids: &[(); wgc::MAX_BIND_GROUPS],
            }),
        };
        let descriptor = pipe::RenderPipelineDescriptor {
@@ -1389,7 +1382,7 @@ impl crate::Context for Context {
        let (id, error) = wgc::gfx_select!(device.id => global.device_create_render_pipeline(
            device.id,
            &descriptor,
-            PhantomData,
+            (),
            implicit_pipeline_ids
        ));
        if let Some(cause) = error {
@@ -1418,8 +1411,8 @@ impl crate::Context for Context {
        let implicit_pipeline_ids = match desc.layout {
            Some(_) => None,
            None => Some(wgc::device::ImplicitPipelineIds {
-                root_id: PhantomData,
-                group_ids: &[PhantomData; wgc::MAX_BIND_GROUPS],
+                root_id: (),
+                group_ids: &[(); wgc::MAX_BIND_GROUPS],
            }),
        };
        let descriptor = pipe::ComputePipelineDescriptor {
@@ -1435,7 +1428,7 @@ impl crate::Context for Context {
        let (id, error) = wgc::gfx_select!(device.id => global.device_create_compute_pipeline(
            device.id,
            &descriptor,
-            PhantomData,
+            (),
            implicit_pipeline_ids
        ));
        if let Some(cause) = error {
@@ -1467,7 +1460,7 @@ impl crate::Context for Context {
        let (id, error) = wgc::gfx_select!(device.id => global.device_create_buffer(
            device.id,
            &desc.map_label(|l| l.map(Borrowed)),
-            PhantomData
+            ()
        ));
        if let Some(cause) = error {
            self.handle_error(
@@ -1493,7 +1486,7 @@ impl crate::Context for Context {
        let (id, error) = wgc::gfx_select!(device.id => global.device_create_texture(
            device.id,
            &desc.map_label(|l| l.map(Borrowed)),
-            PhantomData
+            ()
        ));
        if let Some(cause) = error {
            self.handle_error(
@@ -1536,7 +1529,7 @@ impl crate::Context for Context {
        let (id, error) = wgc::gfx_select!(device.id => global.device_create_sampler(
            device.id,
            &descriptor,
-            PhantomData
+            ()
        ));
        if let Some(cause) = error {
            self.handle_error(
@@ -1559,7 +1552,7 @@ impl crate::Context for Context {
        let (id, error) = wgc::gfx_select!(device.id => global.device_create_query_set(
            device.id,
            &desc.map_label(|l| l.map(Borrowed)),
-            PhantomData
+            ()
        ));
        if let Some(cause) = error {
            self.handle_error_nolabel(&device.error_sink, cause, "Device::create_query_set");
@@ -1576,7 +1569,7 @@ impl crate::Context for Context {
        let (id, error) = wgc::gfx_select!(device.id => global.device_create_command_encoder(
            device.id,
            &desc.map_label(|l| l.map(Borrowed)),
-            PhantomData
+            ()
        ));
        if let Some(cause) = error {
            self.handle_error(
@@ -1742,7 +1735,7 @@ impl crate::Context for Context {
        };
        let global = &self.0;
        let (id, error) = wgc::gfx_select!(
-            texture.id => global.texture_create_view(texture.id, &descriptor, PhantomData)
+            texture.id => global.texture_create_view(texture.id, &descriptor, ())
        );
        if let Some(cause) = error {
            self.handle_error(
@@ -1848,7 +1841,7 @@ impl crate::Context for Context {
        index: u32,
    ) -> Self::BindGroupLayoutId {
        let global = &self.0;
-        let (id, error) = wgc::gfx_select!(*pipeline => global.compute_pipeline_get_bind_group_layout(*pipeline, index, PhantomData));
+        let (id, error) = wgc::gfx_select!(*pipeline => global.compute_pipeline_get_bind_group_layout(*pipeline, index, ()));
        if let Some(err) = error {
            panic!("Error reflecting bind group {}: {}", index, err);
        }
@@ -1860,7 +1853,7 @@ impl crate::Context for Context {
        index: u32,
    ) -> Self::BindGroupLayoutId {
        let global = &self.0;
-        let (id, error) = wgc::gfx_select!(*pipeline => global.render_pipeline_get_bind_group_layout(*pipeline, index, PhantomData));
+        let (id, error) = wgc::gfx_select!(*pipeline => global.render_pipeline_get_bind_group_layout(*pipeline, index, ()));
        if let Some(err) = error {
            panic!("Error reflecting bind group {}: {}", index, err);
        }
@@ -2183,7 +2176,7 @@ impl crate::Context for Context {
        let (id, error) = wgc::gfx_select!(encoder.parent() => global.render_bundle_encoder_finish(
            encoder,
            &desc.map_label(|l| l.map(Borrowed)),
-            PhantomData
+            ()
        ));
        if let Some(err) = error {
            self.handle_error_fatal(err, "RenderBundleEncoder::finish");
@@ -2230,7 +2223,7 @@ impl crate::Context for Context {
    ) -> QueueWriteBuffer {
        let global = &self.0;
        match wgc::gfx_select!(
-            *queue => global.queue_create_staging_buffer(*queue, size, PhantomData)
+            *queue => global.queue_create_staging_buffer(*queue, size, ())
        ) {
            Ok((buffer_id, ptr)) => QueueWriteBuffer {
                buffer_id,