src/doc/book/nostarch/chapter09-read-to-string-update.md

   1 Please insert this text after the paragraph ending in “ergonomic way to write
   2 it” on page 160.
   3
   4 ---
   5
   6 Speaking of different ways to write this function, Listing 9-9 shows that
   7 there’s a way to make this even shorter.
   8
   9 Filename: src/main.rs
  10
  11 ```
  12 use std::io;
  13 use std::fs;
  14
  15 fn read_username_from_file() -> Result<String, io::Error> {
  16     fs::read_to_string("hello.txt")
  17 }
  18 ```
  19
  20 Listing 9-9: Using `fs::read_to_string` instead of opening and then reading the
  21 file
  22
  23 Reading a file into a string is a fairly common operation, so Rust provides the
  24 convenient `fs::read_to_string` function that opens the file, creates a new
  25 `String`, reads the contents of the file, puts the contents into that `String`,
  26 and returns it. Of course, using `fs::read_to_string` doesn’t give us the
  27 opportunity to explain all the error handling, so we did it the longer way
  28 first.