#std #extensions #helpers #utils


Extensions for the Rust standard library structures

6 releases

0.3.1 Jul 11, 2021
0.3.0 Jun 18, 2021
0.2.1 Jul 9, 2020
0.1.1 Jun 28, 2020

#208 in Rust patterns

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41,588 downloads per month
Used in 262 crates (9 directly)

MIT license

804 lines

std extensions

Status: CI

Project info: Docs.rs Latest Version License Rust 1.53+ required

Additional features for the Rust standard library.


This crate contains enhancements to the Rust standard library structures, useful for broad audience, but not yet implemented (or stabilized) in std.

Crate is designed to be lightweight (no external dependencies!) and provide essential functionality which possible can get to the std some day.

The minimal supported Rust version for release 0.3 is 1.53. However, if you need to use this crate with an older version of the compiler, check out release 0.2; there is a good chance that it will suit your needs.


  • Integer super-trait that is implemented for all the built-in integers and reflects the common part of their interfaces.

    use stdext::prelude::*;
    fn accepts_any_integer<I: Integer>(a: I, b: I) {
      println!("{}", (a + b).count_ones());
  • Safe conversions from floating numbers to integers.

    use stdext::prelude::FloatConvert;
    let valid: Option<u8> = 10.5f32.checked_floor();
    let too_big: Option<u8> = 256f32.checked_floor();
    let nan: Option<u8> = f32::NAN.checked_floor();
    assert_eq!(valid, Some(10u8));
    assert_eq!(too_big, None);
    assert_eq!(nan, None);
  • Convenient builder methods for Duration:

    use std::time::Duration;
    use stdext::prelude::*;
    let duration = Duration::from_minutes(1).add_secs(5).add_micros(100);
    assert_eq!(duration, Duration::new(65, 100_000));
  • Panicking version for RwLock::read, RwLock::write and Mutex::lock (for fellows who don't really handle the lock poisoning):

    use std::sync::{Arc, RwLock};
    use stdext::prelude::*;
    let lock = Arc::new(RwLock::new(1));
        let mut n = lock.force_write(); // Instead of `.write().unwrap()`.
        *n = 2;
    let n = lock.force_read();
    assert_eq!(*n, 2);
  • Result::combine and Option::combine to zip pairs of objects:

    use stdext::prelude::*;
    let x = Some(1);
    let y = Some("hi");
    let z = None::<u8>;
    assert_eq!(x.combine(y), Some((1, "hi")));
    assert_eq!(x.combine(z), None);
    let x = Ok(1);
    let y = Ok("hi");
    let z: Result<i32, &str> = Err("error");
    let z2: Result<i32, &str> = Err("other_error");
    assert_eq!(x.combine(y), Ok((1, "hi")));
    assert_eq!(x.combine(z), Err("error"));
    assert_eq!(z.combine(z2), Err("error"));
  • New handy macros (mostly for development purposes):

    use stdext::{compile_warning, function_name};
    fn sample_function() {
      println!("This function is called {}", function_name!());
      compile_warning!("This function must do something else...");

...and other features. For a full list, check out the crate documentation.


Standard library is great, and it becomes even better through time. However, a time gap between proposing a new feature and getting it stabilized is way too big.

This crate, however, can be updated quickly and the feature will be usable on the stable Rust soon after implementation.


If you want to contribute to this project, please read the contributing guide.


stdext library is licensed under the MIT License. See LICENSE for details.

No runtime deps