Struct async_codec_util::decoder::Map

pub struct Map<R, D, F> { /* fields omitted */ }

Change the return type of a decoder by mapping its item through a function.

Methods

impl<R, D, F> Map<R, D, F>

pub fn new(decoder: D, f: F) -> Map<R, D, F>

Chain a compution on the result of a decoder.

Trait Implementations

impl<R, D, F, U> AsyncDecode<R> for Map<R, D, F> where
    R: AsyncRead,
    D: AsyncDecode<R>,
    F: FnOnce(D::Item) -> U, 

type Item = U

The type of the value to decode.

type Error = D::Error

An error indicating how decoding can fail.

fn poll_decode(
    &mut self,
    cx: &mut Context,
    reader: &mut R
) -> Poll<(Option<Self::Item>, usize), DecodeError<Self::Error>>

Call reader.poll_read exactly once, propgating any Err and Pending, and return how many bytes have been read, as well as the decoded value, once decoding is done.