message: Make ChannelsType nonexhaustive
diff: @@ -19,6 +19,9 @@ pub enum ChannelsType {
  Bgr,
  /// Blue, green, red and alpha
  Bgra,
  +
  + #[doc(hidden)]
  + __Nonexhaustive,
  }
  impl ChannelsType {
  @@ -30,6 +33,7 @@ impl ChannelsType {
  Self::Rgba => 4,
  Self::Bgr => 3,
  Self::Bgra => 4,
  + Self::__Nonexhaustive => unreachable!(),
  }
  }
  }
  @@ -237,6 +241,7 @@ impl<T: Primitive + 'static> Pixel for $ident<T> {
  (ChannelsType::Rgba, _) => ColorType::Rgba16,
  (ChannelsType::Bgr, _) => ColorType::Bgr8,
  (ChannelsType::Bgra, _) => ColorType::Bgra8,
  + (ChannelsType::__Nonexhaustive, _) => unreachable!(),
  }
  }
  