Function fn_factory 

pub fn fn_factory<F, S, St, Req, Err>(f: F) -> FnFactory<F, S, St, Req, Err>
where
    F: AsyncFn(&St) -> Result<S, Err>,
    S: Service<St, Req>,

Converts an asynchronous constructor function into a ServiceFactory.

Any function with the form AsyncFn(&State) -> Result<Service, InitError> can act as a factory.

Example

use std::io;
use ntex_service::{factory, fn_factory, fn_service, Pipeline, Service, ServiceFactory};

#[ntex::main]
async fn main() -> io::Result<()> {
    // Create a factory that uses the state to configure each service.
    let fac = fn_factory(async |y: &usize| {
        let y = *y;
        Ok::<_, io::Error>(fn_service(move |x: usize| async move { Ok::<_, io::Error>(x * y) }))
    });

    // Construct a service with the supplied state.
    let srv = Pipeline::new((), factory(fac).create(&10).await?);

    let result = srv.call(10).await?;
    assert_eq!(result, 100);

    println!("10 * 10 = {}", result);
    Ok(())
}