Follow the steps to implement this recipe:

1. Open the main.rs file in the src directory in your preferred text editor.
2. Write the code header with the relevant information:

        //-- #########################
        //-- Task: Testing rust-clippy tool
        //-- Author: Vigneshwer.D
        //-- Version: 1.0.0
        //-- Date: 28 April 17
        //-- #########################

3. Create a main function, and copy and paste the code:

        fn main(){
        let x = Some(1u8);
        match x {
          Some(y) => println!("{:?}", y),
          _ => ()
        }
        }

4. Copy and paste the code snippet above the main function at the beginning of the code to use rust-clippy as an optional dependency:

      #![cfg_attr(feature="clippy", feature(plugin))]

      #![cfg_attr(feature="clippy", plugin(clippy))]

5. Run Clippy with the command cargo build --features "clippy".
6. For running Clippy as a subcommand, run the following command:

        cargo clippy

7. Copy paste the code snippet above the main function at the beginning of the code to use rust-clippy as a compiler plugin:

        #![feature(plugin)]
        #![plugin(clippy)]

8. When we run the cargo run command, Cargo will install Clippy and show a warning.

We will get the following output for the preceding three different methods:

• Running Clippy as an optional dependency:

• Running Clippy as a Cargo subcommand:

• Running Clippy as a compiler plugin: