## `while let`
In a similar fashion, `while let` can be used when you want to conditionally
-loop as long as a value matches a certain pattern. It turns code like this:
+loop over an iterator as long as a value matches a certain pattern. It turns
+code like this:
```rust
# let option: Option<i32> = None;
Into code like this:
```rust
-# let option: Option<i32> = None;
-while let Some(x) = option {
+# let v: vec![1, 3, 5, 7, 9, ];
+# let mut it: v.iter();
+while let Some(x) = it.next() {
println!("{}", x);
}
```