Derive Macro OverrideConfig

#[derive(OverrideConfig)]
{
    // Attributes available to this derive:
    #[override_opts]
}

Sections in the configuration file can use #[derive(OverrideConfig)] to generate the implementation of overwriting configs from the file.

In the struct definition, use #[override_opts(path = …)] on a field to indicate the field in RwConfig to override.

An example:

#[derive(OverrideConfig)]
struct Opts {
    #[override_opts(path = meta.listen_addr)]
    listen_addr: Option<String>,
}

will generate

impl OverrideConfig for Opts {
    fn r#override(self, config: &mut RwConfig) {
        if let Some(v) = self.required_str {
            config.meta.listen_addr = v;
        }
    }
}