Macro peel_ip::prelude::count_fixed

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

count_fixed!(O, I -> IResult<I,O>, nb) => I -> IResult<I, [O; nb]> Applies the child parser a fixed number of times and returns a fixed size array The type must be specified and it must be Copy

 named!(counter< [&[u8]; 2] >, count_fixed!( &[u8], tag!( "abcd" ), 2 ) );
 // can omit the type specifier if returning slices
 // named!(counter< [&[u8]; 2] >, count_fixed!( tag!( "abcd" ), 2 ) );

 let a = b"abcdabcdabcdef";
 let b = b"abcdefgh";
 let res = [&b"abcd"[..], &b"abcd"[..]];

 assert_eq!(counter(&a[..]), Done(&b"abcdef"[..], res));
 assert_eq!(counter(&b[..]), Error(error_position!(ErrorKind::Count, &b[..])));