Async postgres client (compact api)

[package]
name = "tokio-psql"
version = "0.1.0"
authors = ["Jinhua Luo <home_king@163.com>"]
edition = "2018"

[dependencies]
futures-preview = "=0.3.0-alpha.19"
tokio = "0.2.0-alpha.6"
tokio-postgres= { git = "https://github.com/sfackler/rust-postgres" }

--------------

use futures::FutureExt;
use tokio_postgres::{Error, NoTls, Row};

#[tokio::main]
async fn main() -> Result<(), Error> {
    // Connect to the database.
    let (client, connection) =
        tokio_postgres::connect("host=localhost user=postgres", NoTls).await?;

    // The connection object performs the actual communication with the database,
    // so spawn it off to run on its own.
    let connection = connection.map(|r| {
        if let Err(e) = r {
            eprintln!("connection error: {}", e);
        }
    });
    tokio::spawn(connection);

    // Now we can prepare a simple statement that just returns its parameter.
    let stmt = client.prepare("SELECT $1::TEXT").await?;

    // And then execute it, returning a Stream of Rows which we collect into a Vec.
    let rows: Vec<Row> = client.query(&stmt, &[&"hello world"]).await?;

    // Now we can check that we got back the same string we sent over.
    let value: &str = rows[0].get(0);
    assert_eq!(value, "hello world");

    Ok(())
}