temporary value does not live long enough

temporary value does not live long enough.rs

#[derive(Debug)]
struct MyString {
    s:String,
}


impl MyString {
    fn to_str(&self) -> &str {
        &self.s
    }
}

fn main() {
    let s = MyString {s:"1".to_string()};
    let t = s.to_str();
    // let  s2 = MyString {s:"1".to_string()}.to_str();
    // does not work. It seems to be equivalent to
    // let s3 = {
    //    MyString {s:"1".to_string()}
    // }.to_str();
    println!("{:?}", s);
}