Struct Unsupported 

pub struct Unsupported<E>(/* private fields */);

Stub type for codecs that don’t support an operation.

Use as the associated type for unsupported decode modes:

impl<'a> DecodeJob<'a> for MyDecodeJob<'a> {
    type Error = At<MyError>;  // or just MyError
    type Dec = MyDecoder<'a>;
    type StreamDec = Unsupported<At<MyError>>;
    type AnimationFrameDec = Unsupported<At<MyError>>;
    // ...

    fn streaming_decoder(self, ..) -> Result<Unsupported<At<MyError>>, At<MyError>> {
        Err(MyError::from(UnsupportedOperation::RowLevelDecode).start_at())
    }

    fn animation_frame_decoder(self, ..) -> Result<Unsupported<At<MyError>>, At<MyError>> {
        Err(MyError::from(UnsupportedOperation::AnimationDecode).start_at())
    }
}

The job’s method returns Err(...) before an Unsupported instance is ever created, so the trait methods below are unreachable in practice.

Trait Implementations

impl<E: Error + Send + Sync + 'static> AnimationFrameDecoder for Unsupported<E>

type Error = E

The codec-specific error type.

fn wrap_sink_error(_err: SinkError) -> E

Wrap a SinkError into this decoder’s error type.

fn info(&self) -> &ImageInfo

Image metadata, available after construction.

fn render_next_frame( &mut self, _stop: Option<&dyn Stop>, ) -> Result<Option<AnimationFrame<'_>>, E>

Render the next composited full-canvas frame.

fn render_next_frame_owned( &mut self, _stop: Option<&dyn Stop>, ) -> Result<Option<OwnedAnimationFrame>, E>

Render the next frame as an owned copy.

fn render_next_frame_to_sink( &mut self, _stop: Option<&dyn Stop>, _sink: &mut dyn DecodeRowSink, ) -> Result<Option<OutputInfo>, E>

Render the next frame directly into a caller-owned sink (push model).

fn frame_count(&self) -> Option<u32>

Number of frames, if known without decoding.

fn loop_count(&self) -> Option<u32>

Animation loop count from the container.

impl<E: Error + Send + Sync + 'static> StreamingDecode for Unsupported<E>

type Error = E

The codec-specific error type.

fn next_batch(&mut self) -> Result<Option<(u32, PixelSlice<'_>)>, E>

Pull the next batch of scanlines.

fn info(&self) -> &ImageInfo

Image metadata, available after construction.