Trait Source

pub trait Source {
    type Item;

    // Required method
    fn next(&mut self) -> Self::Item;

    // Provided method
    fn size_hint(&self) -> (usize, Option<usize>) { ... }
}

This trait allows receiving items from somewhere.

Types implementing this trait are called “sources”.

Required Associated Types

type Item

The type of items the source receives.

Required Methods

fn next(&mut self) -> Self::Item

Get the next item.

Provided Methods

fn size_hint(&self) -> (usize, Option<usize>)

Get an estimation of the number of items yet to be received.

Returns a tuple where the 2 elements are the lower and upper bounds of the number of items expected to be received. The upper bound is an Option<usize> to account for cases where the upper bound is not known. In such cases, implementations should return None as the upper bound.

The default implementation returns (0, None).

Implementors

impl<R, D> Source for FramedRead<R, D>

where R: Read, D: Decoder,

Available on crate feature alloc only.

type Item = Result<<D as Decoder>::Output, FramedReadError<<D as Decoder>::Error, <R as Read>::Error>>