Function patch 

pub fn patch<I: 'static, R, E: Render, F>(
    pattern: impl Into<String>,
    f: F,
) -> Route<I, R, E>
where
    F: Fn(&mut Context<'_, I, E>) -> Result + Send + Sync + 'static,

A route with a PATCH handler.

use web_net::{App, patch};

let app = App::builder()
    .route(patch("/items/:id", |cx| cx.text(200, "changed")).csrf_exempt("example: no browser form"))
    .build()?;
let r = serve_net::testing::respond(
    &app,
    b"PATCH /items/1 HTTP/1.1\r\nHost: localhost\r\nContent-Length: 0\r\n\r\n",
);
assert_eq!(r.text(), "changed");