Result<T, Error>

This is a reasonable return type to use throughout your application but also for fn main; if you do, failures will be printed along with any [context][Context] and a backtrace if one was captured.

anyhow::Result may be used with one or two type parameters.

use anyhow::Result;

# const IGNORE: &str = stringify! {
fn demo1() -> Result<T> {...}
           // ^ equivalent to std::result::Result<T, anyhow::Error>

fn demo2() -> Result<T, OtherError> {...}
           // ^ equivalent to std::result::Result<T, OtherError>
# };

Example

# pub trait Deserialize {}
#
# mod serde_json {
#     use super::Deserialize;
#     use std::io;
#
#     pub fn from_str<T: Deserialize>(json: &str) -> io::Result<T> {
#         unimplemented!()
#     }
# }
#
# #[derive(Debug)]
# struct ClusterMap;
#
# impl Deserialize for ClusterMap {}
#
use anyhow::Result;

fn main() -> Result<()> {
    # return Ok(());
    let config = std::fs::read_to_string("cluster.json")?;
    let map: ClusterMap = serde_json::from_str(&config)?;
    println!("cluster info: {:#?}", map);
    Ok(())
}