struct A {
}

struct B {
}

impl From<A> for B {
    fn from(a: A) -> Self {
        B { }
    }
}

struct C<Inner> {
    inner: Inner,
}

impl From<C<A>> for C<B> {
    fn from(c: C<A>) -> Self {
        C { inner: c.inner.into() }
    }
}

fn main () {}