4 releases (2 breaking)

0.3.0 Mar 19, 2023
0.2.0 May 7, 2022
0.1.1 Apr 29, 2022
0.1.0 Apr 28, 2022

#350 in Rust patterns

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Named Tups

github crates.io docs.rs

Provides a new type called Named Tups that can be called using the tup! macro. Named Tups are structs that can contain a set of named arguments, effectively they work like normal tuples that can be accessed and created using an actual name.

The idea of named tuples is to provide a way to quickly iterate on ideas without having to create a builder struct or losing the ability to type check at compile time. Named tuples also allow the creation of default values that can replace nonexistent arguments.

named-tup = "0.3.0"

inwelling = "0.4.0"


And put the following in your build.rs file.

fn main() {

If you would prefer for this crate to not scan your project files to determine what named arguments are being used add a list of the named tup arguments you used in your Cargo.toml like so.

arguments = ["count", "ingredients", "eggs", "price"]


use named_tup::tup;
let count = 5;

// This will have the type of Tup!(count: i32, ingredients: [&str; 3], eggs: bool)
let cakes = tup!(count, ingredients: ["milk", "flower", "sugar"], eggs: true);

// We can just add a price afterwards
let mut cakes = cakes + tup!(price: 3);
// And now it has the type of Tup!(eggs: bool, ingredients: [&str; 3], count: i32, price: i32)

// Once the price is in the tup we can just update it!
cakes.price = 4;

// Will print tup { count: 5, eggs: true, ingredients: ["milk", "flower", "sugar"], price: 4 }

To use defaults just annotate the item where you set a field with #[tup_default]. Additionally since the defaulted tup! is a type you need to convert into it by calling .into_tup() which can be accessed through the TupInto trait.

use named_tup::{tup, Tup, tup_default, TupInto};

let options = tup!(read: false, write: true);

// Converts to Tup!(read: false, write: true, create: false, timeout: 5)
open_file("main.rs", options.into_tup());

fn open_file(
    path: &str,
    options: Tup!(
        read: bool = true,
        write: bool = false,
        create: bool = false,
        timeout: i32 = 5
    // Open the file

To test the crate enable the feature dev-test.


  • Write some more tests
  • Serialise and Deserialise using Serde
  • Provide nice looking types for cargo doc


Licensed under either of Apache License, Version 2.0 or MIT license at your option.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in this crate by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.


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