Clippy Example

Example code:

fn main() {
    let pi = 3.14;
    let diameter = 1_f64;

    println!("Circumference: {}", diameter * pi);
}

Apply clippy:

play (main #) $ cargo clippy
    Checking play v0.1.0 (/Users/joseph/Temp/play)
error: approximate value of `f{32, 64}::consts::PI` found. Consider using it directly
 --> src/main.rs:2:14
  |
2 |     let pi = 3.14;
  |              ^^^^
  |
  = note: `#[deny(clippy::approx_constant)]` on by default
  = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#approx_constant

error: aborting due to previous error

error: could not compile `play`

To learn more, run the command again with --verbose.