<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `actix-http/src/body/either.rs`."><title>either.rs - source</title><script>if(window.location.protocol!=="file:")document.head.insertAdjacentHTML("beforeend","SourceSerif4-Regular-46f98efaafac5295.ttf.woff2,FiraSans-Regular-018c141bf0843ffd.woff2,FiraSans-Medium-8f9a781e4970d388.woff2,SourceCodePro-Regular-562dcc5011b6de7d.ttf.woff2,SourceCodePro-Semibold-d899c5a5c4aeb14a.ttf.woff2".split(",").map(f=>`<link rel="preload" as="font" type="font/woff2" crossorigin href="../../../static.files/${f}">`).join(""))</script><link rel="stylesheet" href="../../../static.files/normalize-76eba96aa4d2e634.css"><link rel="stylesheet" href="../../../static.files/rustdoc-dd39b87e5fcfba68.css"><meta name="rustdoc-vars" data-root-path="../../../" data-static-root-path="../../../static.files/" data-current-crate="actix_http" data-themes="" data-resource-suffix="" data-rustdoc-version="1.80.0-nightly (bdbbb6c6a 2024-05-26)" data-channel="nightly" data-search-js="search-d52510db62a78183.js" data-settings-js="settings-4313503d2e1961c2.js" ><script src="../../../static.files/storage-118b08c4c78b968e.js"></script><script defer src="../../../static.files/src-script-e66d777a5a92e9b2.js"></script><script defer src="../../../src-files.js"></script><script defer src="../../../static.files/main-20a3ad099b048cf2.js"></script><noscript><link rel="stylesheet" href="../../../static.files/noscript-df360f571f6edeae.css"></noscript><link rel="icon" href="https://actix.rs/favicon.ico"></head><body class="rustdoc src"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><div class="src-sidebar-title"><h2>Files</h2></div></nav><div class="sidebar-resizer"></div><main><rustdoc-search></rustdoc-search><section id="main-content" class="content"><div class="example-wrap"><div data-nosnippet><pre class="src-line-numbers"><a href="#1" id="1">1</a>
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</pre></div><pre class="rust"><code><span class="kw">use </span>std::{
pin::Pin,
task::{Context, Poll},
};
<span class="kw">use </span>bytes::Bytes;
<span class="kw">use </span>pin_project_lite::pin_project;
<span class="kw">use super</span>::{BodySize, BoxBody, MessageBody};
<span class="kw">use </span><span class="kw">crate</span>::Error;
<span class="macro">pin_project!</span> {
<span class="doccomment">/// An "either" type specialized for body types.
///
/// It is common, in middleware especially, to conditionally return an inner service's unknown/
/// generic body `B` type or return early with a new response. This type's "right" variant
/// defaults to `BoxBody` since error responses are the common case.
///
/// For example, middleware will often have `type Response = ServiceResponse<EitherBody<B>>`.
/// This means that the inner service's response body type maps to the `Left` variant and the
/// middleware's own error responses use the default `Right` variant of `BoxBody`. Of course,
/// there's no reason it couldn't use `EitherBody<B, String>` instead if its alternative
/// responses have a known type.
</span><span class="attr">#[project = EitherBodyProj]
#[derive(Debug, Clone)]
</span><span class="kw">pub enum </span>EitherBody<L, R = BoxBody> {
<span class="doccomment">/// A body of type `L`.
</span>Left { <span class="attr">#[pin] </span>body: L },
<span class="doccomment">/// A body of type `R`.
</span>Right { <span class="attr">#[pin] </span>body: R },
}
}
<span class="kw">impl</span><L> EitherBody<L, BoxBody> {
<span class="doccomment">/// Creates new `EitherBody` left variant with a boxed right variant.
///
/// If the expected `R` type will be inferred and is not `BoxBody` then use the
/// [`left`](Self::left) constructor instead.
</span><span class="attr">#[inline]
</span><span class="kw">pub fn </span>new(body: L) -> <span class="self">Self </span>{
<span class="self">Self</span>::Left { body }
}
}
<span class="kw">impl</span><L, R> EitherBody<L, R> {
<span class="doccomment">/// Creates new `EitherBody` using left variant.
</span><span class="attr">#[inline]
</span><span class="kw">pub fn </span>left(body: L) -> <span class="self">Self </span>{
<span class="self">Self</span>::Left { body }
}
<span class="doccomment">/// Creates new `EitherBody` using right variant.
</span><span class="attr">#[inline]
</span><span class="kw">pub fn </span>right(body: R) -> <span class="self">Self </span>{
<span class="self">Self</span>::Right { body }
}
}
<span class="kw">impl</span><L, R> MessageBody <span class="kw">for </span>EitherBody<L, R>
<span class="kw">where
</span>L: MessageBody + <span class="lifetime">'static</span>,
R: MessageBody + <span class="lifetime">'static</span>,
{
<span class="kw">type </span>Error = Error;
<span class="attr">#[inline]
</span><span class="kw">fn </span>size(<span class="kw-2">&</span><span class="self">self</span>) -> BodySize {
<span class="kw">match </span><span class="self">self </span>{
EitherBody::Left { body } => body.size(),
EitherBody::Right { body } => body.size(),
}
}
<span class="attr">#[inline]
</span><span class="kw">fn </span>poll_next(
<span class="self">self</span>: Pin<<span class="kw-2">&mut </span><span class="self">Self</span>>,
cx: <span class="kw-2">&mut </span>Context<<span class="lifetime">'_</span>>,
) -> Poll<<span class="prelude-ty">Option</span><<span class="prelude-ty">Result</span><Bytes, <span class="self">Self</span>::Error>>> {
<span class="kw">match </span><span class="self">self</span>.project() {
EitherBodyProj::Left { body } => body
.poll_next(cx)
.map_err(|err| Error::new_body().with_cause(err)),
EitherBodyProj::Right { body } => body
.poll_next(cx)
.map_err(|err| Error::new_body().with_cause(err)),
}
}
<span class="attr">#[inline]
</span><span class="kw">fn </span>try_into_bytes(<span class="self">self</span>) -> <span class="prelude-ty">Result</span><Bytes, <span class="self">Self</span>> {
<span class="kw">match </span><span class="self">self </span>{
EitherBody::Left { body } => body
.try_into_bytes()
.map_err(|body| EitherBody::Left { body }),
EitherBody::Right { body } => body
.try_into_bytes()
.map_err(|body| EitherBody::Right { body }),
}
}
<span class="attr">#[inline]
</span><span class="kw">fn </span>boxed(<span class="self">self</span>) -> BoxBody {
<span class="kw">match </span><span class="self">self </span>{
EitherBody::Left { body } => body.boxed(),
EitherBody::Right { body } => body.boxed(),
}
}
}
<span class="attr">#[cfg(test)]
</span><span class="kw">mod </span>tests {
<span class="kw">use super</span>::<span class="kw-2">*</span>;
<span class="attr">#[test]
</span><span class="kw">fn </span>type_parameter_inference() {
<span class="kw">let </span>_body: EitherBody<(), <span class="kw">_</span>> = EitherBody::new(());
<span class="kw">let </span>_body: EitherBody<<span class="kw">_</span>, ()> = EitherBody::left(());
<span class="kw">let </span>_body: EitherBody<(), <span class="kw">_</span>> = EitherBody::right(());
}
}
</code></pre></div></section></main></body></html>