fn c<F, G, A, B, C>(f: F, g: G) -> impl Fn(A) -> C
where
    F: Fn(A) -> B,
    G: Fn(B) -> C,
{
    move |x| g(f(x))
}


fn f(x: u32) -> u32 {
    x * 2
}

fn g(x: u32) -> u32 {
    x * 3
}

fn main() {

    let h = c(f, g);

    println!("{}", h(10));
    println!("{}", f(10));
    println!("{}", g(10));

}