lifetime.rs

struct Path<'a> {
    path: &'a str,
}

impl<'a> Path<'a> {
    fn new(path: &str) -> Path {
        Path { path }
    }

    fn query(&self) -> &'a str {
        if let Some(i) = self.path.find('?') {
            &self.path[i..]
        } else {
            self.path
        }
    }
}

fn query(path: &str) -> &str {
    // we have to explicitly tie the lifetime of the str passed into Path
    // with the slice that is returned or it will be coerced into
    // the lifetime of the borrowed self which doesn't live past this
    // function call
    Path::new(path).query()
}

fn main() {
    println!("{}", query("http://example.com/path?query=1"))
}