use std::marker::PhantomData;
trait Lolka {}

pub struct LolkaImpl;

impl Lolka for LolkaImpl {}

struct Instance<CFG=LolkaImpl> {
    _temp: PhantomData<CFG>
}

impl<CFG: Lolka> Instance<CFG> {
    pub fn new() -> Instance<CFG> {
        Self {
            _temp: PhantomData
        }
    }
}

fn main() {
    let test = Instance::new();
}