Method fmt

Rust/notes.rs:117–130

This trait requires `fmt` with this exact signature.

(&self, f: &mut std::fmt::Formatter)

    impl std::fmt::Display for Point2D {
        // This trait requires `fmt` with this exact signature.
        fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
            // Write strictly the first element into the supplied output
            // stream: `f`. Returns `fmt::Result` which indicates whether the
            // operation succeeded or failed. Note that `write!` uses syntax which
            // is very similar to `println!`.
            // write!(f, "x: {}, y: {}", self.x, self.y) // If it was a tupple, we could access if like self.0, self.1

            // Rust provides the ? operator, which can be combined with write! for complex writes
            // Try `write!` to see if it errors. If it errors, return the error. Otherwise continue.
            // As an example (This is the equivalent solution from the above):
            // Use this trick for more complex structures that need to break in steps the print sequence
            write!(f, "x: {}", self.x)?;
            write!(f, ", y: {}", self.y)
        }
    }

    let point = Point2D { x: 3.3, y: 7.2 };