radix! { Binary,    2, "0b", x @  0 ..=  1 => b'0' + x }
right_arrow! {NonZeroI8(i8) -> NonZeroU8(u8);}
fn f() {
matches!(a, b if c < d);
matches!(*self, '!'..='/' | ':'..='@');
test!{0 1 2  4
    }
m!(&v[..], [N(0), sub @ .., N(4)] => c!(sub, &[N], n![1, 2, 3]));
quote! { &self.#field_ident }
async_assert_fn!(tokio_stream::empty<Rc<u8>>(): Send & Sync);
a!(Timeout<BoxFutureSync<()>>: Send & Sync & !Unpin);
}