FromIterator

function.rs

    fn packagist_versions_from_json<'a>(&self, json: &'a Json) -> Option<Version> {
        json.find_path(&[&"package".to_string(), &"versions".to_string()])
            .and_then(|versions_json| versions_json.as_object())
            .and_then(|versions_map| {
                versions_map.keys().map(|version_string| {
                    println!("version {}, {}", version_string, Version::parse(version_string.as_slice()));
                    Version::parse(version_string.as_slice()).ok()
                }).fold(None, |a, b| {
                    match (a, b) {
                        (None, b@_) => b,
                        (a@Some(_), None) => a,
                        (Some(a), Some(b)) => Some(max(a, b))
                    }
                })
            })
    }

gistfile1.txt

/home/robin/dev/rust-composer-check/src/main.rs:74:17: 81:28 error: the trait `core::iter::FromIterator<semver::version::Version>` is not implemented for the type `semver::version::Version`
/home/robin/dev/rust-composer-check/src/main.rs:74                 versions_map.values().map(|version_json|
/home/robin/dev/rust-composer-check/src/main.rs:75                     version_json.find(&"version".to_string())
/home/robin/dev/rust-composer-check/src/main.rs:76                         .and_then(|version_json_string| version_json_string.as_string())
/home/robin/dev/rust-composer-check/src/main.rs:77                         .and_then(|version_string| {
/home/robin/dev/rust-composer-check/src/main.rs:78                             println!("version {}, {}", version_string, Version::parse(version_string))
/home/robin/dev/rust-composer-check/src/main.rs:79                             Version::parse(version_string).ok()