How can I convert a struct to another struct with exactly the same field names and types?

I've got two identical structs with the same name, fields (and field types), that live in different modules. These are constructed by a derive macro and would like to easily convert from one to the other.

e.g.

mod a {
    struct A {
        field1: String,
        field2: String,
    }
}

mod b {
    struct A {
        field1: String,
        field2: String,
    }
}

I'd like to be able to do let a: a::A = a::A::from(b::A) or similar.

impl From<b::A> for a::A requires writing all the fields from both structs in the from() method. Is there any way to achieve this without all the associated boilerplate?

It seems that until something like this is implemented the only way to achieve this conversion is serialising:

impl From<b::A> for a::A {
    fn from(a: b::A) -> Self {
        let serialised = serde_json::to_value(&a).unwrap();
        serde_json::from_value(&serialised).unwrap()
    }
}

Source