macro_rules! destructure_field{
    ($matched:expr; $($variant:path),+ => $value:ident) => (
        match $matched {
            $($variant($value))|+ => $value
        }
    );
    // Problematic variant
    ($matched:expr; $($variant:path),+ => $($values:ident),+) => (
        match $matched {
            // nested repetition occurs here
            $($variant($($values),+))|+ => ($($values),+)
        }
    )
}

enum Test<'a> {
    A(&'a str, usize),
    B(&'a str, usize),
    C(&'a str, usize),
    D(&'a str, usize)
}

impl<'a> Test<'a> {
    fn get_content(&self) -> (&str, usize) {
        destructure_field!(self; Test::A, Test::B, Test::C, Test::D => string, number)
    }
}

fn main() {
    let (string, number) = Test::B("This is a test!", 5).get_content();
    println!("{}{}", string, number);
}