I just had a thought: Why should `response::Headers` be generic, but
`body::StreamBody` should not? `StreamBody` previously boxed the stream
to erase the generics. So we had `response::Headers<T>` but
`body::StreamBody`, without generics.
After thinking about it I think it actually makes sense for responses to
remain generic because you're able to use `impl IntoResponse` so you
don't have to name the generics.
Whereas in the case of `BodyStream` (an extractor) you cannot use `impl Trait`
so it makes sense to box the inner body to make the type easier to name. Besides,
`BodyStream` is mostly useful when the request body isn't `hyper::Body`, as
that already implements `Stream`.
This adds `StreamBody` which converts a `Stream` of `Bytes` into a `http_body::Body`.
---
As suggested by Kestrer on Discord it would make sense for axum to provide different kinds of body types other than `Empty`, `Full`, and `hyper::Body`. There is also some talk about [splitting up `hyper::Body`](https://github.com/hyperium/hyper/issues/2345) so this can be seen as getting started on that effort. axum's body types could be moved to hyper or http-body if thats the direction we decide on.
The types I'm thinking about adding are:
- `StreamBody`- added in this PR
- `AsyncReadBody` - similar to [http-body#41](https://github.com/hyperium/http-body/pull/41/files)
- `ChannelBody` - similar to `hyper::Body::channel`
This way there is now only one way to create a router:
```rust
use axum::{Router, handler::get};
let app = Router::new()
.route("/foo", get(handler))
.route("/foo", get(handler));
```
`nest` was changed in the same way:
```rust
use axum::Router;
let app = Router::new().nest("/foo", service);
```
* Add `Headers`
Example usage:
```rust
use axum::{
route,
routing::RoutingDsl,
response::{IntoResponse, Headers},
handler::get,
};
use http::header::{HeaderName, HeaderValue};
// It works with any `IntoIterator<Item = (Key, Value)>` where `Key` can be
// turned into a `HeaderName` and `Value` can be turned into a `HeaderValue`
//
// Such as `Vec<(HeaderName, HeaderValue)>`
async fn just_headers() -> impl IntoResponse {
Headers(vec![
(HeaderName::from_static("X-Foo"), HeaderValue::from_static("foo")),
])
}
// Or `[(&str, &str)]`
async fn from_strings() -> impl IntoResponse {
Headers([("X-Foo", "foo")])
}
```
Fixes https://github.com/tokio-rs/axum/issues/187
* Make work on Rust versions without `IntoIterator` for arrays
* format
* changelog
David Pedersen