Customizing errors

While the Result type doesn't care about the type it returns in the Err branch, returning String instances for error messages is not ideal either. Typical errors have several things to consider:

• Is there a root cause or error?
• What is the error message?
• Is there a more in-depth message to output?

The standard library's errors all follow a common trait from std::error::Error—let's see how they are implemented.

How to do it...

Defining error types is not hard—just follow these steps:

1. Create a new project with cargo new custom-errors and open it with VS Code.
2. Using VS Code, open src/main.rs and create a basic struct called MyError:

use std::fmt;
use std::error::Error;

#[derive...