Bug: 146584155

Clone this repo:
  1. 506e6d2 Upgrade bitflags to 2.4.2 am: 5fc2b79734 by Stephen Hines · 8 weeks ago emu-34-2-dev main master
  2. 5fc2b79 Upgrade bitflags to 2.4.2 by Stephen Hines · 8 weeks ago emu-34-3-release
  3. a15185e Migrate to cargo_embargo. am: e2d1b9e3f6 am: 6e7aa0fc86 am: 1c029fcac0 by Andrew Walbran · 4 months ago
  4. c7a098b Migrate to cargo_embargo. am: e2d1b9e3f6 am: 840989e390 am: b0ed7e9002 by Andrew Walbran · 4 months ago
  5. 1c029fc Migrate to cargo_embargo. am: e2d1b9e3f6 am: 6e7aa0fc86 by Andrew Walbran · 4 months ago

bitflags

Rust Latest version Documentation License

bitflags generates flags enums with well-defined semantics and ergonomic end-user APIs.

You can use bitflags to:

  • provide more user-friendly bindings to C APIs where flags may or may not be fully known in advance.
  • generate efficient options types with string parsing and formatting support.

You can't use bitflags to:

  • guarantee only bits corresponding to defined flags will ever be set. bitflags allows access to the underlying bits type so arbitrary bits may be set.

  • define bitfields. bitflags only generates types where set bits denote the presence of some combination of flags.

  • Documentation

  • Specification

  • Release notes

Usage

Add this to your Cargo.toml:

[dependencies]
bitflags = "2.4.2"

and this to your source code:

use bitflags::bitflags;

Example

Generate a flags structure:

use bitflags::bitflags;

// The `bitflags!` macro generates `struct`s that manage a set of flags.
bitflags! {
    /// Represents a set of flags.
    #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
    struct Flags: u32 {
        /// The value `A`, at bit position `0`.
        const A = 0b00000001;
        /// The value `B`, at bit position `1`.
        const B = 0b00000010;
        /// The value `C`, at bit position `2`.
        const C = 0b00000100;

        /// The combination of `A`, `B`, and `C`.
        const ABC = Self::A.bits() | Self::B.bits() | Self::C.bits();
    }
}

fn main() {
    let e1 = Flags::A | Flags::C;
    let e2 = Flags::B | Flags::C;
    assert_eq!((e1 | e2), Flags::ABC);   // union
    assert_eq!((e1 & e2), Flags::C);     // intersection
    assert_eq!((e1 - e2), Flags::A);     // set difference
    assert_eq!(!e2, Flags::A);           // set complement
}

Rust Version Support

The minimum supported Rust version is documented in the Cargo.toml file. This may be bumped in minor releases as necessary.