custom_derive.rs - mozsearch

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//! 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() {}