Another kind of manual map

[ronnodas]

What it does

Replace Some(f(...?)) or Ok(f(...)?) as a return value with (...).map(f). Potentially an addition to manual_map.

Advantage

Clearer, has less nesting, and can be more concise. Helps discoverability of Option::map etc.

Drawbacks

Can be less concise.

Example

fn maybe_len(maybe_string: Option<&str>) -> Option<usize> {
    Some(maybe_string?.len())
}

Could be written as:

fn maybe_len(maybe_string: Option<&str>) -> Option<usize> {
    maybe_some_string.map(|s| s.len())
}

[Jarcho]

This is only the same if the value is immediately returned. This also seems a bit more pedantic than manual_map.