Tune mtl api

cidre/src/mtl/texture.rs

@@ -62,6 +62,7 @@ pub enum Swizzle {
     Alpha = 5,
 }
 
+#[doc(alias = "MTLTextureSwizzleChannels")]
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 #[repr(C)]
 pub struct SwizzleChannels {
@@ -264,7 +265,7 @@ impl Texture {
     /// The texture this texture view was created from, or [`None`] if this is not
     /// a texture view or it was not created from a texture.
     #[objc::msg_send(parentTexture)]
-    pub fn parent_texture(&self) -> Option<&Texture>;
+    pub fn parent_texture(&self) -> Option<arc::R<Texture>>;
 
     #[objc::msg_send(newTextureViewWithPixelFormat:)]
     pub fn new_texture_view_with_pixel_format(
@@ -275,7 +276,7 @@ impl Texture {
     /// The buffer this texture view was created from, or [`None`] if this is not a texture
     /// view or it was not created from a buffer.
     #[objc::msg_send(buffer)]
-    pub fn buf(&self) -> Option<&mtl::Buf>;
+    pub fn buf(&self) -> Option<arc::R<mtl::Buf>>;
 
     /// The offset of the buffer this texture view was created from, or 0 if this is not a texture view.
     #[objc::msg_send(bufferOffset)]