trait Fromable {
    fn create() -> Self;
}

struct A;

impl Fromable for A {
    fn create() -> Self {
        A {}
    }
}

fn construct<T: Fromable>() -> impl Fromable {
    T::create()
}

fn main() {
    let s = "'A";

    match s {
        "'A" => Some(construct::<A>()),
        _ => None
    };
}