Merge pull request #56 from mina86/a

Add bytemuck feature and implement some bytemuck traits for Pixel type

Cargo.toml

@@ -36,6 +36,9 @@ rayon = { version = "1.11", optional = true }
 ## [DynamicImage](https://docs.rs/image/latest/image/enum.DynamicImage.html)
 ## type from the `image` crate.
 image = ["dep:image", "dep:bytemuck"]
+## Enable this feature to implement traits [bytemuck::Pod] and
+## [bytemuck::Zeroable] for `Pixel` type.
+bytemuck = ["dep:bytemuck"]
 ## This feature enables image processing in the ` rayon ` thread pool.
 rayon = ["dep:rayon", "resize/rayon", "image/rayon"]
 for_testing = ["image", "image/png"]

src/pixels.rs

@@ -208,6 +208,25 @@ where
     }
 }
 
+// SAFETY: bytemuck derives are tripped by the use of generic arguments.
+// However, since Pixel<T, _, _> is repr(C) it introduces no padding after T nor
+// imposes any additional limitations on T.  Hence, if T is Zeroable, Pixel is
+// Zeroable.
+#[cfg(feature = "bytemuck")]
+unsafe impl<T: bytemuck::Zeroable, C, const COUNT_OF_COMPONENTS: usize>
+    bytemuck::Zeroable for Pixel<T, C, COUNT_OF_COMPONENTS>
+where
+    T: Sized + Copy + Clone + PartialEq + Default + 'static,
+    C: PixelComponent {}
+
+// SAFETY: As above.  If T is Pod than Pixel<T> is Pod.
+#[cfg(feature = "bytemuck")]
+unsafe impl<T: bytemuck::Pod, C, const COUNT_OF_COMPONENTS: usize>
+    bytemuck::Pod for Pixel<T, C, COUNT_OF_COMPONENTS>
+where
+    T: Sized + Copy + Clone + PartialEq + Default + 'static,
+    C: PixelComponent {}
+
 macro_rules! pixel_struct {
     ($name:ident, $type:tt, $comp_type:tt, $comp_count:literal, $pixel_type:expr, $doc:expr) => {
         #[doc = $doc]