fune/third_party/rust/bitflags/examples/custom_derive.rs
Mike Hommey 1ce83241da Bug 1852209 - Switch to bitflags 2 r=supply-chain-reviewers,emilio
We currently are using a fake bitflags 2, derived from bitflags 1. More
and more crates are using it, and we're at a sweet spot where flipping
things around makes sense: using a fake bitflags 1, derived from
bitflags 2.

Differential Revision: https://phabricator.services.mozilla.com/D189316
2023-09-27 19:56:17 +00:00

23 lines
644 B
Rust

//! An example of implementing the `BitFlags` trait manually for a flags type.
use std::str;
use bitflags::bitflags;
// Define a flags type outside of the `bitflags` macro as a newtype
// It can accept custom derives for libaries `bitflags` doesn't support natively
#[derive(zerocopy::AsBytes, zerocopy::FromBytes)]
#[repr(transparent)]
pub struct ManualFlags(u32);
// Next: use `impl Flags` instead of `struct Flags`
bitflags! {
impl ManualFlags: u32 {
const A = 0b00000001;
const B = 0b00000010;
const C = 0b00000100;
const ABC = Self::A.bits() | Self::B.bits() | Self::C.bits();
}
}
fn main() {}