change to iterate over &vet

diff --git a/src/doc/intro.md b/src/doc/intro.md
index eb190d2ab2e0ef8bbefcbfc8353d419cad54abea..07a90959deb693b30fbf629a50d950c9c52cc03c 100644 (file)
--- a/src/doc/intro.md
+++ b/src/doc/intro.md
@@ -565,7 +565,7 @@ while retaining safety. The answer is iterators:
 ```{rust}
 let vec = vec![1, 2, 3];
 
-for x in vec {
+for x in &vec {
     println!("{}", x);
 }
 ```