2.6.0

What's Changed

New Contributors

Full Changelog: https://github.com/bitflags/bitflags/compare/2.5.0...2.6.0

2.5.0

What's Changed

New Contributors

Full Changelog: https://github.com/bitflags/bitflags/compare/2.4.2...2.5.0

2.4.2

What's Changed

New Contributors

Full Changelog: https://github.com/bitflags/bitflags/compare/2.4.1...2.4.2

2.4.1

What's Changed

Full Changelog: https://github.com/bitflags/bitflags/compare/2.4.0...2.4.1

2.4.0

What's Changed

New Contributors

Full Changelog: https://github.com/bitflags/bitflags/compare/2.3.3...2.4.0

2.3.3

Changes to -=

The -= operator was incorrectly changed to truncate bits that didn't correspond to valid flags in 2.3.0. This has been fixed up so it once again behaves the same as - and difference.

Changes to !

The ! operator previously called Self::from_bits_truncate, which would truncate any bits that only partially overlapped with a valid flag. It will now use bits & Self::all().bits(), so any bits that overlap any bits specified by any flag will be respected. This is unlikely to have any practical implications, but enables defining a flag like const ALL = !0 as a way to signal that any bit pattern is a known set of flags.

Changes to formatting

Zero-valued flags will never be printed. You'll either get 0x0 for empty flags using debug formatting, or the set of flags with zero-valued flags omitted for others.

Composite flags will no longer be redundantly printed if there are extra bits to print at the end that don't correspond to a valid flag.

What's Changed

Full Changelog: https://github.com/bitflags/bitflags/compare/2.3.2...2.3.3

2.3.2

What's Changed

New Contributors

Full Changelog: https://github.com/bitflags/bitflags/compare/2.3.1...2.3.2

2.3.1

What's Changed

Full Changelog: https://github.com/bitflags/bitflags/compare/2.3.0...2.3.1

2.3.0

Major changes

BitFlags trait deprecated in favor of Flags trait

This release introduces the Flags trait and deprecates the BitFlags trait. These two traits are semver compatible so if you have public API code depending on BitFlags you can move to Flags without breaking end-users. This is possible because the BitFlags trait was never publicly implementable, so it now carries Flags as a supertrait. All implementations of Flags additionally implement BitFlags.

The Flags trait is a publicly implementable version of the old BitFlags trait. The original BitFlags trait carried some macro baggage that made it difficult to implement, so a new Flags trait has been introduced as the One True Trait for interacting with flags types generically. See the the macro_free and custom_derive examples for more details.

Bits trait publicly exposed

The Bits trait for the underlying storage of flags values is also now publicly implementable. This lets you define your own exotic backing storage for flags. See the custom_bits_type example for more details.

What's Changed

Full Changelog: https://github.com/bitflags/bitflags/compare/2.2.1...2.3.0

2.2.1

What's Changed

Full Changelog: https://github.com/bitflags/bitflags/compare/2.2.0...2.2.1

2.2.0

What's Changed

New Contributors

Full Changelog: https://github.com/bitflags/bitflags/compare/2.1.0...2.2.0

2.1.0

What's Changed

New Contributors

Full Changelog: https://github.com/bitflags/bitflags/compare/2.0.2...2.1.0

2.0.2

What's Changed

Full Changelog: https://github.com/bitflags/bitflags/compare/2.0.1...2.0.2

2.0.1

What's Changed

New Contributors

Full Changelog: https://github.com/bitflags/bitflags/compare/2.0.0...2.0.1

2.0.0

Major changes

This release includes some major changes over 1.x. If you use bitflags! types in your public API then upgrading this library may cause breakage in your downstream users.

⚠️ Serialization

You'll need to add the serde Cargo feature in order to #[derive(Serialize, Deserialize)] on your generated flags types:

bitflags! {
    #[derive(Serialize, Deserialize)]
    #[serde(transparent)]
    pub struct Flags: T {
        ..
    }
}

where T is the underlying bits type you're using, such as u32.

The default serialization format with serde has changed if you #[derive(Serialize, Deserialize)] on your generated flags types. It will now use a formatted string for human-readable formats and the underlying bits type for compact formats.

To keep the old format, see the https://github.com/KodrAus/bitflags-serde-legacy library.

⚠️ Traits

Generated flags types now derive fewer traits. If you need to maintain backwards compatibility, you can derive the following yourself:

#[derive(PartialEq, Eq, PartialOrd, Ord, Hash, Debug, Clone, Copy)]

⚠️ Methods

The unsafe from_bits_unchecked method is now a safe from_bits_retain method.

You can add the following method to your generated types to keep them compatible:

#[deprecated = "use the safe `from_bits_retain` method instead"]
pub unsafe fn from_bits_unchecked(bits: T) -> Self {
    Self::from_bits_retain(bits)
}

where T is the underlying bits type you're using, such as u32.

⚠️ .bits field

You can now use the .bits() method instead of the old .bits.

The representation of generated flags types has changed from a struct with the single field bits to a newtype.

What's Changed

New Contributors

Full Changelog: https://github.com/bitflags/bitflags/compare/1.3.2...2.0.0

2.0.0-rc.3

What's Changed

New Contributors

Full Changelog: https://github.com/bitflags/bitflags/compare/2.0.0-rc.2...2.0.0-rc.3

2.0.0-rc.2

Changes to serde serialization

⚠️ NOTE ⚠️ This release changes the default serialization you'll get if you #[derive(Serialize, Deserialize)] on your generated flags types. It will now use a formatted string for human-readable formats and the underlying bits type for compact formats.

To keep the old behavior, see the bitflags-serde-legacy library.

What's Changed

New Contributors

Full Changelog: https://github.com/bitflags/bitflags/compare/2.0.0-rc.1...2.0.0-rc.2

2.0.0-rc.1

This is a big release including a few years worth of work on a new BitFlags trait, iteration, and better macro organization for future extensibility.

What's Changed

New Contributors

Full Changelog: https://github.com/bitflags/bitflags/compare/1.3.2...2.0.0-rc.1

1.3.2

  • Allow non_snake_case in generated flags types (#256)

1.3.1

  • Revert unconditional #[repr(transparent)] (#252)

1.3.0 (yanked)

This release bumps the Minimum Supported Rust Version to 1.46.0

  • Add #[repr(transparent)] (#187)

  • End empty doc comment with full stop (#202)

  • Fix typo in crate root docs (#206)

  • Document from_bits_unchecked unsafety (#207)

  • Let is_all ignore extra bits (#211)

  • Allows empty flag definition (#225)

  • Making crate accessible from std (#227)

  • Make from_bits a const fn (#229)

  • Allow multiple bitflags structs in one macro invocation (#235)

  • Add named functions to perform set operations (#244)

  • Fix typos in method docs (#245)

  • Modernization of the bitflags macro to take advantage of newer features and 2018 idioms (#246)

  • Fix regression (in an unreleased feature) and simplify tests (#247)

  • Use Self and fix bug when overriding stringify! (#249)

1.2.1

  • Remove extraneous #[inline] attributes (#194)

1.2.0

  • Fix typo: {Lower, Upper}Exp - {Lower, Upper}Hex (#183)

  • Add support for “unknown” bits (#188)

1.1.0

This is a re-release of 1.0.5, which was yanked due to a bug in the RLS.

1.0.5

  • Use compiletest_rs flags supported by stable toolchain (#171)

  • Put the user provided attributes first (#173)

  • Make bitflags methods const on newer compilers (#175)

1.0.4

  • Support Rust 2018 style macro imports (#165)

    use bitflags::bitflags;

1.0.3

  • Improve zero value flag handling and documentation (#157)

1.0.2

  • 30% improvement in compile time of bitflags crate (#156)

  • Documentation improvements (#153)

  • Implementation cleanup (#149)

1.0.1

  • Add support for pub(restricted) specifier on the bitflags struct (#135)
  • Optimize performance of all() when called from a separate crate (#136)

1.0.0

  • [breaking change] Macro now generates associated constants (#24)

  • [breaking change] Minimum supported version is Rust 1.20, due to usage of associated constants

  • After being broken in 0.9, the #[deprecated] attribute is now supported again (#112)

  • Other improvements to unit tests and documentation (#106 and #115)

How to update your code to use associated constants

Assuming the following structure definition:

bitflags! {
  struct Something: u8 {
     const FOO = 0b01,
     const BAR = 0b10
  }
}

In 0.9 and older you could do:

let x = FOO.bits | BAR.bits;

Now you must use:

let x = Something::FOO.bits | Something::BAR.bits;

0.9.1

  • Fix the implementation of Formatting traits when other formatting traits were present in scope (#105)

0.9.0

  • [breaking change] Use struct keyword instead of flags to define bitflag types (#84)

  • [breaking change] Terminate const items with semicolons instead of commas (#87)

  • Implement the Hex, Octal, and Binary formatting traits (#86)

  • Printing an empty flag value with the Debug trait now prints “(empty)” instead of nothing (#85)

  • The bitflags! macro can now be used inside of a fn body, to define a type local to that function (#74)

0.8.2

  • Update feature flag used when building bitflags as a dependency of the Rust toolchain

0.8.1

  • Allow bitflags to be used as a dependency of the Rust toolchain

0.8.0

  • Add support for the experimental i128 and u128 integer types (#57)
  • Add set method: flags.set(SOME_FLAG, true) or flags.set(SOME_FLAG, false) (#55) This may break code that defines its own set method

0.7.1

(yanked)

0.7.0

  • Implement the Extend trait (#49)
  • Allow definitions inside the bitflags! macro to refer to items imported from other modules (#51)

0.6.0

  • The no_std feature was removed as it is now the default
  • The assignment_operators feature was remove as it is now enabled by default
  • Some clippy suggestions have been applied