Rust try_collect

pub fn try_collect<Item, Error, Iter: std::iter::Iterator<Item=Result<Item, Error>>, Collection: Default + Extend<Item>>(iter: Iter) -> Result<Collection, Error> {
    let mut values: Collection = Default::default();
    for item in iter {
        match item {
            Ok(v) => values.extend(std::iter::once(v)),
            Err(err) => return Err(err),
        }   
    }   
    return Ok(values)
}