Enum HeaderData

pub enum HeaderData<'a> {
    Str(Box<dyn ExactSizeIterator<Item = (&'a str, &'a str)> + 'a>),
    Bytes(Box<dyn ExactSizeIterator<Item = (&'a [u8], &'a [u8])> + 'a>),
    Parsed(Box<dyn ExactSizeIterator<Item = (&'a HeaderName, &'a HeaderValue)> + 'a>),
}

Internals

We need dyn dispatch for the ExactSizeIterator contained here since we have no idea at time of usage what the actual type may be. We “could” use three generics for each possible contained concrete ExactSizeIterator however it would substantially pollute the api. We would need to encode some of the ExactSizeIterator Item into each usage site, see below.

fn provide_headers<'s, IS, IB, IP>(&'s self, dk: DataKinds) -> Option<HeaderData<'s>>
where IS: ExactSizeIterator<Item = (&'s str, &'s str)>,
      IB: ExactSizeIterator<Item = (&'s [u8], &'s [u8])>,
      IP: ExactSizeIterator<Item = (&'s ::http::HeaderName, &'s ::http::HeaderValue)>;

We tried to use a & dyn ExactSizeIterator<Item = (..)> here but the issue is on implementation we will be returning a reference to an ExactSizeIterator created on the stack (without bending over backwards).

Variants

Str(Box<dyn ExactSizeIterator<Item = (&'a str, &'a str)> + 'a>)

Bytes(Box<dyn ExactSizeIterator<Item = (&'a [u8], &'a [u8])> + 'a>)

Parsed(Box<dyn ExactSizeIterator<Item = (&'a HeaderName, &'a HeaderValue)> + 'a>)

Implementations

impl HeaderData<'_>

pub fn len(&self) -> usize