Merge pull request #1742 from mfasold/patch-1

Update read_lines example to flatten iterator

Author: marioidival

src/std_misc/file/read_lines.md

@@ -56,10 +56,8 @@ fn main() {
     // File hosts.txt must exist in the current path
     if let Ok(lines) = read_lines("./hosts.txt") {
         // Consumes the iterator, returns an (Optional) String
-        for line in lines {
-            if let Ok(ip) = line {
-                println!("{}", ip);
-            }
+        for line in lines.flatten() {
+            println!("{}", line);
         }
     }
 }