Macro peel_ip::prelude::length_bytes

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

length_bytes!(&[T] -> IResult<&[T], nb>) => &[T] -> IResult<&[T], &[T]> Gets a number from the first parser, then extracts that many bytes from the remaining stream