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

How to use with cargo:

[dependencies]
either = "1"

Recent Changes

• 1.15.0
  • Fix serde support when building without std, by @klkvr (#119)
  • Use a more common std feature for default enablement, deprecating the use_std feature as a mere alias of the new name.
• 1.14.0
  • MSRV: either now requires Rust 1.63 or later.
  • Implement fmt::Write for Either, by @yotamofek (#113)
  • Replace Into<Result> for Either with From<Either> for Result, by @cuviper (#118)
• 1.13.0
  • Add new methods .cloned() and .copied(), by @ColonelThirtyTwo (#107)
• 1.12.0
  • MSRV: either now requires Rust 1.37 or later.
  • Specialize nth_back for Either and IterEither, by @cuviper (#106)
• 1.11.0
  • Add new trait IntoEither that is useful to convert to Either in method chains, by @SFM61319 (#101)
• 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 reference 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.