Macro peel_ip::prelude::recognize

macro_rules! recognize {
    ( $ i : expr , $ submac : ident ! ( $ ( $ args : tt ) * ) ) => { ... };
    ( $ i : expr , $ f : expr ) => { ... };
}

recognize!(&[T] -> IResult<&[T], O> ) => &[T] -> IResult<&[T], &[T]> if the child parser was successful, return the consumed input as produced value

 named!(x, recognize!(delimited!(tag!("<!--"), take!(5), tag!("-->"))));
 let r = x(&b"<!-- abc --> aaa"[..]);
 assert_eq!(r, Done(&b" aaa"[..], &b"<!-- abc -->"[..]));