43 releases (24 stable)
2.6.0 | Jun 24, 2024 |
---|---|
2.5.0 | Mar 19, 2024 |
2.4.2 | Jan 16, 2024 |
2.4.1 | Oct 15, 2023 |
0.1.1 | Feb 9, 2015 |
#1 in Rust patterns
21,890,327 downloads per month
Used in 71,580 crates
(2,902 directly)
145KB
3.5K
SLoC
bitflags
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.
Usage
Add this to your Cargo.toml
:
[dependencies]
bitflags = "2.6.0"
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.
Dependencies
~0–430KB