To squash to 6bc4ca4: sealed encodable layout trait

src/buffer.rs

@@ -8,7 +8,7 @@ use color::{ChannelsType, ColorType, FromColor, Luma, LumaA, Rgb, Rgba, Bgr, Bgr
 use flat::{FlatSamples, SampleLayout};
 use dynimage::{save_buffer, save_buffer_with_format};
 use image::{GenericImage, GenericImageView, ImageFormat, ImageResult};
-use traits::{AsBytes, Primitive};
+use traits::{EncodableLayout, Primitive};
 use utils::expand_packed;
 
 
@@ -744,7 +744,7 @@ where
 impl<P, Container> ImageBuffer<P, Container>
 where
     P: Pixel + 'static,
-    [P::Subpixel]: AsBytes,
+    [P::Subpixel]: EncodableLayout,
     Container: Deref<Target = [P::Subpixel]>,
 {
     /// Saves the buffer to a file at the path specified.
@@ -769,7 +769,7 @@ where
 impl<P, Container> ImageBuffer<P, Container>
 where
     P: Pixel + 'static,
-    [P::Subpixel]: AsBytes,
+    [P::Subpixel]: EncodableLayout,
     Container: Deref<Target = [P::Subpixel]>,
 {
     /// Saves the buffer to a file at the specified path in

src/traits.rs

@@ -5,20 +5,20 @@
 use num_traits::{Bounded, Num, NumCast};
 use std::ops::AddAssign;
 
-/// Types which are safe to treat as an immutable byte slice. This is a wrapper
-/// around the `zerocopy::AsBytes` trait.
-pub trait AsBytes {
+/// Types which are safe to treat as an immutable byte slice in a pixel layout
+/// for image encoding.
+pub trait EncodableLayout: seals::EncodableLayout {
     /// Get the bytes of this value.
     fn as_bytes(&self) -> &[u8];
 }
 
-impl<T> AsBytes for T where T: zerocopy::AsBytes {
+impl EncodableLayout for [u8] {
     fn as_bytes(&self) -> &[u8] {
         zerocopy::AsBytes::as_bytes(self)
     }
 }
 
-impl<T> AsBytes for [T] where [T]: zerocopy::AsBytes {
+impl EncodableLayout for [u16] {
     fn as_bytes(&self) -> &[u8] {
         zerocopy::AsBytes::as_bytes(self)
     }
@@ -64,3 +64,12 @@ impl Enlargeable for u16 {
 impl Enlargeable for u32 {
     type Larger = u64;
 }
+
+
+/// Private module for supertraits of sealed traits.
+mod seals {
+    pub trait EncodableLayout {}
+
+    impl EncodableLayout for [u8] {}
+    impl EncodableLayout for [u16] {}
+}