#iterator #first #last


Helper functions to determine the first/last repetition of something

2 unstable releases

Uses old Rust 2015

0.2.0 Jun 30, 2018
0.1.0 Jun 29, 2018

#1494 in Rust patterns


181 lines


Build Status crates.io version docs

This tiny crate contains functions and types to help you do something special when repeating for the first or last time (or in between!). This crate offers two distinct features:

  • IterStatusExt::with_status: a new method for iterators, that creates a new iterator which yields the item paired with information to tell you if this is the first/last item.
  • SkipFirst: a simple struct to help you always do something, except on the first repetition. Works without iterators, too!


(also see examples/)

let names = ["anna", "peter", "brigitte", "bob"];

for (name, status) in names.iter().with_status() {
    print!("{}", name);

    if status.is_first() {
        print!(" <-- winner (ᵔᴥᵔ)");
    if status.is_last_only() {
        print!(" ... ʘ︵ʘ");


The old programming problem – commas in between elements:

let mut comma = SkipFirst::new();

for name in &["banana", "melon", "kiwi"] {
    comma.skip_first(|| print!(", "));
    print!("{}", name);



Licensed under either of

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Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.

No runtime deps