Using Serde on simple Struct that has external struct not Serializable

1

I have a very simple struct:

use internment::Intern;

#[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]
pub struct Name {
    pub(crate) name: Intern<String>,
}

I tried to derive Serialize and Deserialize from the serde crate but it is not implemented for Intern so it didn't work.

I managed to follow the docs and implement a customer Serializer:

impl Serialize for Name {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
        S: Serializer,
    {
        let mut state = serializer.serialize_struct("Name", 1)?;
        state.serialize_field("name", &self.name.deref())?;
        state.end()
    }
}

The docs readily state implementing a Deserializer is more complicated. I probably can muddle through and get it working but on the face of it there is a lot of bolier plate code. Am I doing the right, and necessary thing, for such a basic struct?

2

Note that internment::Intern does implement Serialize and Deserialize, if you enable the serde feature for internment in your Cargo.toml:

[dependencies]
internment = { version = "0.8", features = ["serde"] }
1 Like
3

Ah great, i checked the docs but didn't see the feature. In any case, its fixed now, but had it not implemented serde, was what I was suggesting necessary?

4

Rather than implementing Serialize and Deserialize by hand, you could've tried to use the derive macros for the remote type. I think in your case implementing by hand would've been easier though.

5

You could also use the #[serde(with = ...)] attribute to specify a module with free functions for serialization and deserialization of individual fields. Then you can continue using the derive macro.

6

This topic was automatically closed 90 days after the last reply. We invite you to open a new topic if you have further questions or comments.