Function async_postgres::connect_tls

pub async fn connect_tls<T>(
    config: Config, 
    __arg1: T
) -> Result<(Client, Connection<Socket, T::Stream>)> where
    T: MakeTlsConnect<Socket>, 

Connect to postgres server with a tls connector.

use async_postgres::connect_tls;
use native_tls::{Certificate, TlsConnector};
use postgres_native_tls::MakeTlsConnector;
use std::fs;
use std::error::Error;
use async_std::task::spawn;

async fn play() -> Result<(), Box<dyn Error>> {
    let cert = fs::read("database_cert.pem")?;
    let cert = Certificate::from_pem(&cert)?;
    let connector = TlsConnector::builder()
        .add_root_certificate(cert)
        .build()?;
    let connector = MakeTlsConnector::new(connector);
    let url = "host=localhost user=postgres sslmode=require";
    let (client, conn) = connect_tls(url.parse()?, connector).await?;
    spawn(conn);
    let row = client.query_one("SELECT * FROM user WHERE id=$1", &[&0]).await?;
    let value: &str = row.get(0);
    println!("value: {}", value);
    Ok(())
}