Ch. 02: Consistent ordering of use statements

Adopt the idiomatic pattern of separating `std` from third-party `use`
statements, with the result that we get the ordering we want for Ch. 07
for “free”.

Fixes #3121

Author: chriskrycho

listings/ch02-guessing-game-tutorial/listing-02-03/src/main.rs

@@ -1,5 +1,6 @@
 // ANCHOR: all
 use std::io;
+
 // ANCHOR: ch07-04
 use rand::Rng;
 

listings/ch02-guessing-game-tutorial/listing-02-04/src/main.rs

@@ -1,8 +1,9 @@
 // ANCHOR: here
-use rand::Rng;
 use std::cmp::Ordering;
 use std::io;
 
+use rand::Rng;
+
 fn main() {
     // --snip--
     // ANCHOR_END: here

listings/ch02-guessing-game-tutorial/listing-02-05/src/main.rs

@@ -1,7 +1,8 @@
-use rand::Rng;
 use std::cmp::Ordering;
 use std::io;
 
+use rand::Rng;
+
 fn main() {
     println!("Guess the number!");
 

listings/ch02-guessing-game-tutorial/listing-02-06/src/main.rs

@@ -1,7 +1,8 @@
-use rand::Rng;
 use std::cmp::Ordering;
 use std::io;
 
+use rand::Rng;
+
 fn main() {
     println!("Guess the number!");
 

listings/ch02-guessing-game-tutorial/no-listing-03-convert-string-to-number/src/main.rs

@@ -1,7 +1,8 @@
-use rand::Rng;
 use std::cmp::Ordering;
 use std::io;
 
+use rand::Rng;
+
 fn main() {
     println!("Guess the number!");
 

listings/ch02-guessing-game-tutorial/no-listing-04-looping/src/main.rs

@@ -1,7 +1,8 @@
-use rand::Rng;
 use std::cmp::Ordering;
 use std::io;
 
+use rand::Rng;
+
 fn main() {
     println!("Guess the number!");
 

listings/ch02-guessing-game-tutorial/no-listing-05-quitting/src/main.rs

@@ -1,7 +1,8 @@
-use rand::Rng;
 use std::cmp::Ordering;
 use std::io;
 
+use rand::Rng;
+
 fn main() {
     println!("Guess the number!");