I have an if statement which needs to check for the existence of a value in a nested Option. The statement currently looks like

if my_vec.get(0).is_some() && my_vec.get(0).unwrap().is_some() {      
    // My True Case
} else {
    // My Else Case
}

I feel like this is an amateurish way of checking if this potential nested value exists. I want to maintain safety when fetching the Option from the array as it may or may not exist, and also when unwrapping the Option itself. I tried using and_then and similar operators but haven't had any luck.

CodePudding user response：

I would check the length first and access it like a regular array instead of using .get(x) unless there is some benefit in doing so (like passing it to something which expects an option).

if my_vec.len() > x && my_vec[x].is_some() {
    // etc
}

Another option is to just match the value with an if let x = y or full match statement.

if let Some(Some(_)) = my_vec.get(x) {
    // etc
}

The matches! macro can also be used in this situation similarly to the if let when you don't need to take a reference to the data.

if matches!(my_vec.get(x), Some(Some(_))) {
    // etc
}

Or the and_then version, but personally it is probably my least favorite since it is longer and gargles the intention.

if my_vec.get(x).and_then(|y| y.as_ref()).is_some() {
    // etc
}

You can pick whichever one is your favorite. They all compile down to the same thing (probably, I haven't checked).