RDruon / bitflags-serde-legacy

Implement serde traits for bitflags 2.x types compatibly with 1.x

bitflags-serde-legacy

The serialization format used by bitflags! has changed between 1.x and 2.x. If you previously #[derive(Serialize, Deserialize], then you can use this library to maintain compatibility while upgrading.

Usage

You can either use this as a regular dependency, or pull the source into a private module in your project.

Add bitflags-serde-legacy to your Cargo.toml:

[dependencies.bitflags_serde_legacy]
version = "0.1.1"

Then, replace an existing #[derive(Serialize, Deserialize)] on your bitflags! generated types with the following manual implementations:

use bitflags::bitflags;

bitflags! {
    // #[derive(Serialize, Deserialize)]
    struct Flags: u32 {
        const A = 0b00000001;
        const B = 0b00000010;
        const C = 0b00000100;
        const ABC = Self::A.bits() | Self::B.bits() | Self::C.bits();
    }
}

impl serde::Serialize for Flags {
    fn serialize<S: serde::Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
        bitflags_serde_legacy::serialize(self, "Flags", serializer)
    }
}

impl<'de> serde::Deserialize<'de> for Flags {
    fn deserialize<D: serde::Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error> {
        bitflags_serde_legacy::deserialize("Flags", deserializer)
    }
}