CODEWITHSUNDEEP
rust
Rob Latham
Rob Latham

Reputation: 5223

What are these arguments to Rust's std::fmt::write?

I'm trying to make sure I understand all the examples on http://chrismorgan.info/blog/rust-fizzbuzz.html, and the one thing I am stuck on has nothing to do with FizzBuzz, but instead the arguments to write().

Consider the code below: in a line like Fizz => f.write(b"Fizz"), what is 'b' and where did it come from?

use std::fmt;

enum FizzBuzzItem {
    Fizz,
    Buzz,
    FizzBuzz,
    Number(int),
}

impl fmt::Show for FizzBuzzItem {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        match *self {
            Fizz => f.write(b"Fizz"),
            Buzz => f.write(b"Buzz"),
            FizzBuzz => f.write(b"FizzBuzz"),
            Number(num) => write!(f, "{}", num),
        }
    }
}

Upvotes: 0

Views: 164

Answers (1)

Chris Morgan
Chris Morgan

Reputation: 90752

b"…" is a byte string literal. As "…" has the type &'static str, it has the type &'static [u8].

Upvotes: 2

Related Questions