Storing a reference to self before returning in Rust

Question

I have two structs, A and B, where:

• A will store an immutable reference to objects of B.
• B will store an object of A.

My goal is to insert a reference to the newly created object of B into A::vec_of_b before returning. Here is my attempt at executing above goal:

struct A<'a> {
    vec_of_b: Vec<&'a B<'a>>
}

impl<'a> A<'a> {
    pub fn new() -> Self {
        Self { vec_of_b: Default::default() }
    }
}

struct B<'a> {
    a_struct: A<'a>,
}

impl<'a> B<'a> {
    pub fn new(data: A<'a>) -> Self {
        let mut bvar = Self { a_struct: data };

        // I want to insert a reference to the newly created object `bvar`
        bvar.a_struct.vec_of_b.push(&bvar); // <-- this line throws error

        bvar
    }
}

pub fn main() {
    let a = A::new();
    let mut b = B::new(a);
}

But I received an error related to lifetimes:

error[E0502]: cannot borrow `bvar.a_struct.vec_of_b` as mutable because it is also borrowed as immutable

error[E0515]: cannot return value referencing local variable `bvar`

error[E0505]: cannot move out of `bvar` because it is borrowed

How to solve this problem?