macro_rules! defer {
    ($c:expr, $i:ident( $( $x:expr ),* )) => {{
        $c.defer(|c| $i(c $(, $x)*));
    }}
}
struct Core {}
impl Core {
    fn defer<F>(&mut self, _f: F) where F: FnOnce(&mut Core) + 'static {}
}
fn test(_core: &mut Core, _v1: i32, _v2: i32) {}
fn main() {
    let mut core = Core {};
    defer!(&mut core, test(1, 2));
}