Function extract_version_range

fn extract_version_range<F>(line: &str, parse: F) -> Option<(u32, u32)>
where
    F: Fn(&str) -> Option<u32>,

Takes a directive of the form "<version1> [- <version2>]", returns the numeric representation of <version1> and <version2> as tuple: (<version1> as u32, <version2> as u32).

If the <version2> part is omitted, the second component of the tuple is the same as <version1>.