Function image::codecs::webp::decoder::read_fourcc

pub(crate) fn read_fourcc<R: Read>(
    r: &mut R
) -> ImageResult<Option<ImageResult<WebPRiffChunk>>>

Reads a chunk header FourCC Returns None if and only if we hit end of file reading the four character code of the chunk The inner error is Err if and only if the chunk header FourCC is present but unknown