How to Use the anyhow Crate for Application Errors

Use the anyhow crate to simplify error handling by returning anyhow::Result<T> instead of Result<T, E> and propagating errors with the ? operator. Add anyhow = "1" to your Cargo.toml dependencies, import anyhow::Result and the anyhow! macro, then define functions to return Result types that automatically convert other errors.

use anyhow::{anyhow, Result};

fn read_config() -> Result<String> {
    let content = std::fs::read_to_string("config.txt")?;
    if content.is_empty() {
        return Err(anyhow!("Config file is empty"));
    }
    Ok(content)
}

fn main() -> Result<()> {
    let config = read_config()?;
    println!("Config: {}", config);
    Ok(())
}

The anyhow crate acts as a universal error type that lets you stop writing custom error enums for every function. Instead of manually converting different error types, you just use the ? operator to pass errors up the chain until they reach the main function. Think of it as a single bucket that catches all different types of errors so you don't have to sort them individually.