Given
```rust
fn main() {
let maybe_vec = Some(vec![1,2,3]);
assert_eq!(maybe_vec.len(), 3);
}
```
suggest unwraping `maybe_vec` to call `.len()` on the `Vec<_>`.
```
error[E0624]: method `len` is private
--> $DIR/enum-method-probe.rs:61:9
|
LL | res.len();
| ^^^ private method
--> $SRC_DIR/core/src/option.rs:LL:COL
|
= note: private method defined here
|
note: the method `len` exists on the type `Vec<{integer}>`
--> $SRC_DIR/alloc/src/vec/mod.rs:LL:COL
help: consider using `Option::expect` to unwrap the `Vec<{integer}>` value, panicking if the value is an `Option::None`
|
LL | res.expect("REASON").len();
| +++++++++++++++++
```
