The enum `Either` with variants `Left` and `Right` is a general purpose sum type with two cases.


Keywords
no_std, data-structure, rust
Licenses
MIT/Apache-2.0

Documentation

Either

The enum Either with variants Left and Right and trait implementations including Iterator, Read, Write.

Either has methods that are similar to Option and Result.

Includes convenience macros try_left!() and try_right!() to use for short-circuiting logic.

Please read the API documentation here

build_status crates

How to use with cargo:

[dependencies]
either = "1.10"

Recent Changes

  • 1.10.0
    • Add new methods .factor_iter(), .factor_iter_mut(), and .factor_into_iter() that return Either items, plus .iter() and .iter_mut() to convert to direct referene iterators; by @aj-bagwell and @cuviper (#91)
  • 1.9.0
    • Add new methods .map_either() and .map_either_with(), by @nasadorian (#82)
  • 1.8.1
    • Clarified that the multiple licenses are combined with OR.
  • 1.8.0
    • MSRV: either now requires Rust 1.36 or later.
    • Add new methods .as_pin_ref() and .as_pin_mut() to project a pinned Either as inner Pin variants, by @cuviper (#77)
    • Implement the Future trait, by @cuviper (#77)
    • Specialize more methods of the io traits, by @Kixunil and @cuviper (#75)
  • 1.7.0
    • MSRV: either now requires Rust 1.31 or later.
    • Export the macro for_both!, by @thomaseizinger (#58)
    • Implement the io::Seek trait, by @Kerollmops (#60)
    • Add new method .either_into() for Into conversion, by @TonalidadeHidrica (#63)
    • Add new methods .factor_ok(), .factor_err(), and .factor_none(), by @zachs18 (#67)
    • Specialize source in the Error implementation, by @thomaseizinger (#69)
    • Specialize more iterator methods and implement the FusedIterator trait, by @Ten0 (#66) and @cuviper (#71)
    • Specialize Clone::clone_from, by @cuviper (#72)
  • 1.6.1
    • Add new methods .expect_left(), .unwrap_left(), and equivalents on the right, by @spenserblack (#51)
  • 1.6.0
    • Add new modules serde_untagged and serde_untagged_optional to customize how Either fields are serialized in other types, by @MikailBag (#49)
  • 1.5.3
    • Add new method .map() for Either<T, T> by @nvzqz (#40).
  • 1.5.2
    • Add new methods .left_or(), .left_or_default(), .left_or_else(), and equivalents on the right, by @DCjanus (#36)
  • 1.5.1
    • Add AsRef and AsMut implementations for common unsized types: str, [T], CStr, OsStr, and Path, by @mexus (#29)
  • 1.5.0
    • Add new methods .factor_first(), .factor_second() and .into_inner() by @mathstuf (#19)
  • 1.4.0
    • Add inherent method .into_iter() by @cuviper (#12)
  • 1.3.0
    • Add opt-in serde support by @hcpl
  • 1.2.0
    • Add method .either_with() by @Twey (#13)
  • 1.1.0
    • Add methods left_and_then, right_and_then by @rampantmonkey
    • Include license files in the repository and released crate
  • 1.0.3
    • Add crate categories
  • 1.0.2
    • Forward more Iterator methods
    • Implement Extend for Either<L, R> if L, R do.
  • 1.0.1
    • Fix Iterator impl for Either to forward .fold().
  • 1.0.0
    • Add default crate feature use_std so that you can opt out of linking to std.
  • 0.1.7
    • Add methods .map_left(), .map_right() and .either().
    • Add more documentation
  • 0.1.3
    • Implement Display, Error
  • 0.1.2
    • Add macros try_left! and try_right!.
  • 0.1.1
    • Implement Deref, DerefMut
  • 0.1.0
    • Initial release
    • Support Iterator, Read, Write

License

Dual-licensed to be compatible with the Rust project.

Licensed under the Apache License, Version 2.0 https://www.apache.org/licenses/LICENSE-2.0 or the MIT license https://opensource.org/licenses/MIT, at your option. This file may not be copied, modified, or distributed except according to those terms.